В Обединеното кралство всяка нова услуга преминава през тест за съответствие с обществената мисия от две части. През тест преминават и исканията за съществени промени. Британският регулатор е поискал от обществената телевизия Би Би Си да проведе тест за обществена значимост (PIT), за да позволи публично разглеждане на промените в услугата iPlayer на BBC.
Би Би Си отговаря, че планираните за 2018 и 2019 г. промени не са „съществени“ и следователно не изискват оценка. Регулаторът настоява, че оценка е необходима и иска Би Би Си да представи дългосрочна стратегия за трансформиране на услугата iPlayer, вкл. за ефектите върху всички заинтересовани страни. Обществената телевизия представя исканата стратегия.
Сега е ред на регулатора да прецени дали цената на предложената промяна от гледна точка на значението на услугата – и в резултат регулаторът има три опции – положително решение (Би Би Си може да извърши промяната на iPlayer), отрицателно решение или положително решение с условия.
В методологическо отношение Би Би Си използва количествен и качествен анализ за проучване както на нагласите на аудиторията, така и икономическите ефекти и влиянието върху конкуренцията. Съпътстващи анализи, на които се основава стратегията:
Новите и съществено променяните услуги на обществените медии в ЕС трябва да отговарят на мисията на обществените медии и да се финансират – ако отговарят на мисията – адекватно, не повече и не по-малко.
Как точно се вземат решенията за нови услуги или съществени промени в съществуващите услуги? На базата на каква точно информация БНТ2 промени лицензията си – и СЕМ разреши промените – просто защото това е един от последните примери, иначе може да се пита и за други програми и услуги.
Вярно, законът не изисква тест за обществена значимост на услугите. И все пак – изисква се обосновка, защото за тези услуги се разходва обществен ресурс – държавен бюджет.
Идват избори за генерални директори в двете обществени медии – може някой кандидат да запише в концепцията си, че ще работи за съответствие мисия – бюджет и за модернизиране на правната рамка.
At the 2017 Linux Storage, Filesystem, and Memory-Management Summit (LSFMM), Amir Goldstein presented his work on adding a superblock watch mechanism to provide a scalable way to notify applications of changes in a filesystem. At the 2018 edition of LSFMM, he was back to discuss adding NTFS-like change journals to the kernel in support of backup solutions of various sorts. As a second topic for the session, he also wanted to discuss doing more performance-regression testing for filesystems.
Earlier this month we launched the C5 Instances with Local NVMe Storage and I told you that we would be doing the same for additional instance types in the near future!
Today we are introducing M5 instances equipped with local NVMe storage. Available for immediate use in 5 regions, these instances are a great fit for workloads that require a balance of compute and memory resources. Here are the specs:
Instance Name
vCPUs
RAM
Local Storage
EBS-Optimized Bandwidth
Network Bandwidth
m5d.large
2
8 GiB
1 x 75 GB NVMe SSD
Up to 2.120 Gbps
Up to 10 Gbps
m5d.xlarge
4
16 GiB
1 x 150 GB NVMe SSD
Up to 2.120 Gbps
Up to 10 Gbps
m5d.2xlarge
8
32 GiB
1 x 300 GB NVMe SSD
Up to 2.120 Gbps
Up to 10 Gbps
m5d.4xlarge
16
64 GiB
1 x 600 GB NVMe SSD
2.210 Gbps
Up to 10 Gbps
m5d.12xlarge
48
192 GiB
2 x 900 GB NVMe SSD
5.0 Gbps
10 Gbps
m5d.24xlarge
96
384 GiB
4 x 900 GB NVMe SSD
10.0 Gbps
25 Gbps
The M5d instances are powered by Custom Intel® Xeon® Platinum 8175M series processors running at 2.5 GHz, including support for AVX-512.
You can use any AMI that includes drivers for the Elastic Network Adapter (ENA) and NVMe; this includes the latest Amazon Linux, Microsoft Windows (Server 2008 R2, Server 2012, Server 2012 R2 and Server 2016), Ubuntu, RHEL, SUSE, and CentOS AMIs.
Here are a couple of things to keep in mind about the local NVMe storage on the M5d instances:
Naming – You don’t have to specify a block device mapping in your AMI or during the instance launch; the local storage will show up as one or more devices (/dev/nvme*1 on Linux) after the guest operating system has booted.
Encryption – Each local NVMe device is hardware encrypted using the XTS-AES-256 block cipher and a unique key. Each key is destroyed when the instance is stopped or terminated.
Lifetime – Local NVMe devices have the same lifetime as the instance they are attached to, and do not stick around after the instance has been stopped or terminated.
Available Now M5d instances are available in On-Demand, Reserved Instance, and Spot form in the US East (N. Virginia), US West (Oregon), EU (Ireland), US East (Ohio), and Canada (Central) Regions. Prices vary by Region, and are just a bit higher than for the equivalent M5 instances.
Linus has released the 4.17 kernel, which will indeed be called “4.17”. “No, I didn’t call it 5.0, even though all the git object count numerology was in place for that. It will happen in the not _too_ distant future, and I’m told all the release scripts on kernel.org are ready for it, but I didn’t feel there was any real reason for it.”
Headline features in this release include improved load estimation in the CPU scheduler, raw BPF tracepoints, lazytime support in the XFS filesystem, full in-kernel TLS protocol support, histogram triggers for tracing, mitigations for the latest Spectre variants, and, of course, the removal of support for eight unloved processor architectures.
The German charity Save Nemo works to protect coral reefs, and they are developing Nemo-Pi, an underwater “weather station” that monitors ocean conditions. Right now, you can vote for Save Nemo in the Google.org Impact Challenge.
Save Nemo
The organisation says there are two major threats to coral reefs: divers, and climate change. To make diving saver for reefs, Save Nemo installs buoy anchor points where diving tour boats can anchor without damaging corals in the process.
In addition, they provide dos and don’ts for how to behave on a reef dive.
The Nemo-Pi
To monitor the effects of climate change, and to help divers decide whether conditions are right at a reef while they’re still on shore, Save Nemo is also in the process of perfecting Nemo-Pi.
This Raspberry Pi-powered device is made up of a buoy, a solar panel, a GPS device, a Pi, and an array of sensors. Nemo-Pi measures water conditions such as current, visibility, temperature, carbon dioxide and nitrogen oxide concentrations, and pH. It also uploads its readings live to a public webserver.
The Save Nemo team is currently doing long-term tests of Nemo-Pi off the coast of Thailand and Indonesia. They are also working on improving the device’s power consumption and durability, and testing prototypes with the Raspberry Pi Zero W.
The web dashboard showing live Nemo-Pi data
Long-term goals
Save Nemo aims to install a network of Nemo-Pis at shallow reefs (up to 60 metres deep) in South East Asia. Then diving tour companies can check the live data online and decide day-to-day whether tours are feasible. This will lower the impact of humans on reefs and help the local flora and fauna survive.
A healthy coral reef
Nemo-Pi data may also be useful for groups lobbying for reef conservation, and for scientists and activists who want to shine a spotlight on the awful effects of climate change on sea life, such as coral bleaching caused by rising water temperatures.
A bleached coral reef
Vote now for Save Nemo
If you want to help Save Nemo in their mission today, vote for them to win the Google.org Impact Challenge:
Click “Abstimmen” in the footer of the page to vote
Click “JA” in the footer to confirm
Voting is open until 6 June. You can also follow Save Nemo on Facebook or Twitter. We think this organisation is doing valuable work, and that their projects could be expanded to reefs across the globe. It’s fantastic to see the Raspberry Pi being used to help protect ocean life.
Today, at the AWS Summit in Tokyo we announced a number of updates and new features for Amazon SageMaker. Starting today, SageMaker is available in Asia Pacific (Tokyo)! SageMaker also now supports CloudFormation. A new machine learning framework, Chainer, is now available in the SageMaker Python SDK, in addition to MXNet and Tensorflow. Finally, support for running Chainer models on several devices was added to AWS Greengrass Machine Learning.
Amazon SageMaker Chainer Estimator
Chainer is a popular, flexible, and intuitive deep learning framework. Chainer networks work on a “Define-by-Run” scheme, where the network topology is defined dynamically via forward computation. This is in contrast to many other frameworks which work on a “Define-and-Run” scheme where the topology of the network is defined separately from the data. A lot of developers enjoy the Chainer scheme since it allows them to write their networks with native python constructs and tools.
Luckily, using Chainer with SageMaker is just as easy as using a TensorFlow or MXNet estimator. In fact, it might even be a bit easier since it’s likely you can take your existing scripts and use them to train on SageMaker with very few modifications. With TensorFlow or MXNet users have to implement a train function with a particular signature. With Chainer your scripts can be a little bit more portable as you can simply read from a few environment variables like SM_MODEL_DIR, SM_NUM_GPUS, and others. We can wrap our existing script in a if __name__ == '__main__': guard and invoke it locally or on sagemaker.
import argparse
import os
if __name__ =='__main__':
parser = argparse.ArgumentParser()
# hyperparameters sent by the client are passed as command-line arguments to the script.
parser.add_argument('--epochs', type=int, default=10)
parser.add_argument('--batch-size', type=int, default=64)
parser.add_argument('--learning-rate', type=float, default=0.05)
# Data, model, and output directories
parser.add_argument('--output-data-dir', type=str, default=os.environ['SM_OUTPUT_DATA_DIR'])
parser.add_argument('--model-dir', type=str, default=os.environ['SM_MODEL_DIR'])
parser.add_argument('--train', type=str, default=os.environ['SM_CHANNEL_TRAIN'])
parser.add_argument('--test', type=str, default=os.environ['SM_CHANNEL_TEST'])
args, _ = parser.parse_known_args()
# ... load from args.train and args.test, train a model, write model to args.model_dir.
Then, we can run that script locally or use the SageMaker Python SDK to launch it on some GPU instances in SageMaker. The hyperparameters will get passed in to the script as CLI commands and the environment variables above will be autopopulated. When we call fit the input channels we pass will be populated in the SM_CHANNEL_* environment variables.
from sagemaker.chainer.estimator import Chainer
# Create my estimator
chainer_estimator = Chainer(
entry_point='example.py',
train_instance_count=1,
train_instance_type='ml.p3.2xlarge',
hyperparameters={'epochs': 10, 'batch-size': 64}
)
# Train my estimator
chainer_estimator.fit({'train': train_input, 'test': test_input})
# Deploy my estimator to a SageMaker Endpoint and get a Predictor
predictor = chainer_estimator.deploy(
instance_type="ml.m4.xlarge",
initial_instance_count=1
)
Now, instead of bringing your own docker container for training and hosting with Chainer, you can just maintain your script. You can see the full sagemaker-chainer-containers on github. One of my favorite features of the new container is built-in chainermn for easy multi-node distribution of your chainer training jobs.
There’s a lot more documentation and information available in both the README and the example notebooks.
AWS GreenGrass ML with Chainer
AWS GreenGrass ML now includes a pre-built Chainer package for all devices powered by Intel Atom, NVIDIA Jetson, TX2, and Raspberry Pi. So, now GreenGrass ML provides pre-built packages for TensorFlow, Apache MXNet, and Chainer! You can train your models on SageMaker then easily deploy it to any GreenGrass-enabled device using GreenGrass ML.
JAWS UG
I want to give a quick shout out to all of our wonderful and inspirational friends in the JAWS UG who attended the AWS Summit in Tokyo today. I’ve very much enjoyed seeing your pictures of the summit. Thanks for making Japan an amazing place for AWS developers! I can’t wait to visit again and meet with all of you.
Previously, I showed you how to rotate Amazon RDS database credentials automatically with AWS Secrets Manager. In addition to database credentials, AWS Secrets Manager makes it easier to rotate, manage, and retrieve API keys, OAuth tokens, and other secrets throughout their lifecycle. You can configure Secrets Manager to rotate these secrets automatically, which can help you meet your compliance needs. You can also use Secrets Manager to rotate secrets on demand, which can help you respond quickly to security events. In this post, I show you how to store an API key in Secrets Manager and use a custom Lambda function to rotate the key automatically. I’ll use a Twitter API key and bearer token as an example; you can reference this example to rotate other types of API keys.
The instructions are divided into four main phases:
Store a Twitter API key and bearer token in Secrets Manager.
Create a custom Lambda function to rotate the bearer token.
Configure your application to retrieve the bearer token from Secrets Manager.
Configure Secrets Manager to use the custom Lambda function to rotate the bearer token automatically.
For the purpose of this post, I use the placeholder Demo/Twitter_Api_Key to denote the API key, the placeholder Demo/Twitter_bearer_token to denote the bearer token, and placeholder Lambda_Rotate_Bearer_Token to denote the custom Lambda function. Be sure to replace these placeholders with the resource names from your account.
Phase 1: Store a Twitter API key and bearer token in Secrets Manager
Twitter enables developers to register their applications and retrieve an API key, which includes a consumer_key and consumer_secret. Developers use these to generate a bearer token that applications can then use to authenticate and retrieve information from Twitter. At any given point of time, you can use an API key to create only one valid bearer token.
Start by storing the API key in Secrets Manager. Here’s how:
Figure 1: The “Store a new secret” button in the AWS Secrets Manager console
Select Other type of secrets (because you’re storing an API key).
Input the consumer_key and consumer_secret, and then select Next.
Figure 2: Select the consumer_key and the consumer_secret
Specify values for Secret Name and Description, then select Next. For this example, I use Demo/Twitter_API_Key.
Figure 3: Set values for “Secret Name” and “Description”
On the next screen, keep the default setting, Disable automatic rotation, because you’ll use the same API key to rotate bearer tokens programmatically and automatically. Applications and employees will not retrieve this API key. Select Next.
Figure 4: Keep the default “Disable automatic rotation” setting
Review the information on the next screen and, if everything looks correct, select Store. You’ve now successfully stored a Twitter API key in Secrets Manager.
Next, store the bearer token in Secrets Manager. Here’s how:
From the Secrets Manager console, select Store a new secret, select Other type of secrets, input details (access_token, token_type, and ARN of the API key) about the bearer token, and then select Next.
Figure 5: Add details about the bearer token
Specify values for Secret Name and Description, and then select Next. For this example, I use Demo/Twitter_bearer_token.
Figure 6: Again set values for “Secret Name” and “Description”
Keep the default rotation setting, Disable automatic rotation, and then select Next. You’ll enable rotation after you’ve updated the application to use Secrets Manager APIs to retrieve secrets.
Review the information and select Store. You’ve now completed storing the bearer token in Secrets Manager. I take note of the sample code provided on the review page. I’ll use this code to update my application to retrieve the bearer token using Secrets Manager APIs.
Figure 7: The sample code you can use in your app
Phase 2: Create a custom Lambda function to rotate the bearer token
While Secrets Manager supports rotating credentials for databases hosted on Amazon RDS natively, it also enables you to meet your unique rotation-related use cases by authoring custom Lambda functions. Now that you’ve stored the API key and bearer token, you’ll create a Lambda function to rotate the bearer token. For this example, I’ll create my Lambda function using Python 3.6.
Figure 8: In the Lambda console, select “Create function”
Select Author from scratch. For this example, I use the name Lambda_Rotate_Bearer_Token for my Lambda function. I also set the Runtime environment as Python 3.6.
Figure 9: Create a new function from scratch
This Lambda function requires permissions to call AWS resources on your behalf. To grant these permissions, select Create a custom role. This opens a console tab.
Select Create a new IAM Role and specify the value for Role Name. For this example, I use Role_Lambda_Rotate_Twitter_Bearer_Token.
Figure 10: For “IAM Role,” select “Create a new IAM role”
Next, to define the IAM permissions, copy and paste the following IAM policy in the View Policy Document text-entry field. Be sure to replace the placeholder ARN-OF-Demo/Twitter_API_Key with the ARN of your secret.
Figure 11: The IAM policy pasted in the “View Policy Document” text-entry field
Now, select Allow. This brings me back to the Lambda console with the appropriate Role selected.
Select Create function.
Figure 12: Select the “Create function” button in the lower-right corner
Copy the following Python code and paste it in the Function code section.
import base64
import json
import logging
import os
import boto3
from botocore.vendored import requests
logger = logging.getLogger()
logger.setLevel(logging.INFO)
def lambda_handler(event, context):
"""Secrets Manager Twitter Bearer Token Handler
This handler uses the master-user rotation scheme to rotate a bearer token of a Twitter app.
The Secret PlaintextString is expected to be a JSON string with the following format:
{
'access_token': ,
'token_type': ,
'masterarn':
}
Args:
event (dict): Lambda dictionary of event parameters. These keys must include the following:
- SecretId: The secret ARN or identifier
- ClientRequestToken: The ClientRequestToken of the secret version
- Step: The rotation step (one of createSecret, setSecret, testSecret, or finishSecret)
context (LambdaContext): The Lambda runtime information
Raises:
ResourceNotFoundException: If the secret with the specified arn and stage does not exist
ValueError: If the secret is not properly configured for rotation
KeyError: If the secret json does not contain the expected keys
"""
arn = event['SecretId']
token = event['ClientRequestToken']
step = event['Step']
# Setup the client and environment variables
service_client = boto3.client('secretsmanager', endpoint_url=os.environ['SECRETS_MANAGER_ENDPOINT'])
oauth2_token_url = os.environ['TWITTER_OAUTH2_TOKEN_URL']
oauth2_invalid_token_url = os.environ['TWITTER_OAUTH2_INVALID_TOKEN_URL']
tweet_search_url = os.environ['TWITTER_SEARCH_URL']
# Make sure the version is staged correctly
metadata = service_client.describe_secret(SecretId=arn)
if not metadata['RotationEnabled']:
logger.error("Secret %s is not enabled for rotation" % arn)
raise ValueError("Secret %s is not enabled for rotation" % arn)
versions = metadata['VersionIdsToStages']
if token not in versions:
logger.error("Secret version %s has no stage for rotation of secret %s." % (token, arn))
raise ValueError("Secret version %s has no stage for rotation of secret %s." % (token, arn))
if "AWSCURRENT" in versions[token]:
logger.info("Secret version %s already set as AWSCURRENT for secret %s." % (token, arn))
return
elif "AWSPENDING" not in versions[token]:
logger.error("Secret version %s not set as AWSPENDING for rotation of secret %s." % (token, arn))
raise ValueError("Secret version %s not set as AWSPENDING for rotation of secret %s." % (token, arn))
# Call the appropriate step
if step == "createSecret":
create_secret(service_client, arn, token, oauth2_token_url, oauth2_invalid_token_url)
elif step == "setSecret":
set_secret(service_client, arn, token, oauth2_token_url)
elif step == "testSecret":
test_secret(service_client, arn, token, tweet_search_url)
elif step == "finishSecret":
finish_secret(service_client, arn, token)
else:
logger.error("lambda_handler: Invalid step parameter %s for secret %s" % (step, arn))
raise ValueError("Invalid step parameter %s for secret %s" % (step, arn))
def create_secret(service_client, arn, token, oauth2_token_url, oauth2_invalid_token_url):
"""Get a new bearer token from Twitter
This method invalidates existing bearer token for the Twitter app and retrieves a new one from Twitter.
If a secret version with AWSPENDING stage exists, updates it with the newly retrieved bearer token and if
the AWSPENDING stage does not exist, creates a new version of the secret with that stage label.
Args:
service_client (client): The secrets manager service client
arn (string): The secret ARN or other identifier
token (string): The ClientRequestToken associated with the secret version
oauth2_token_url (string): The Twitter API endpoint to request a bearer token
oauth2_invalid_token_url (string): The Twitter API endpoint to invalidate a bearer token
Raises:
ValueError: If the current secret is not valid JSON
KeyError: If the secret json does not contain the expected keys
ResourceNotFoundException: If the current secret is not found
"""
# Make sure the current secret exists and try to get the master arn from the secret
try:
current_secret_dict = get_secret_dict(service_client, arn, "AWSCURRENT")
master_arn = current_secret_dict['masterarn']
logger.info("createSecret: Successfully retrieved secret for %s." % arn)
except service_client.exceptions.ResourceNotFoundException:
return
# create bearer token credentials to be passed as authorization string to Twitter
bearer_token_credentials = encode_credentials(service_client, master_arn, "AWSCURRENT")
# get the bearer token from Twitter
bearer_token_from_twitter = get_bearer_token(bearer_token_credentials,oauth2_token_url)
# invalidate the current bearer token
invalidate_bearer_token(oauth2_invalid_token_url,bearer_token_credentials,bearer_token_from_twitter)
# get a new bearer token from Twitter
new_bearer_token = get_bearer_token(bearer_token_credentials, oauth2_token_url)
# if a secret version with AWSPENDING stage exists, update it with the lastest bearer token
# if the AWSPENDING stage does not exist, then create the version with AWSPENDING stage
try:
pending_secret_dict = get_secret_dict(service_client, arn, "AWSPENDING", token)
pending_secret_dict['access_token'] = new_bearer_token
service_client.put_secret_value(SecretId=arn, ClientRequestToken=token, SecretString=json.dumps(pending_secret_dict), VersionStages=['AWSPENDING'])
logger.info("createSecret: Successfully invalidated the bearer token of the secret %s and updated the pending version" % arn)
except service_client.exceptions.ResourceNotFoundException:
current_secret_dict['access_token'] = new_bearer_token
service_client.put_secret_value(SecretId=arn, ClientRequestToken=token, SecretString=json.dumps(current_secret_dict), VersionStages=['AWSPENDING'])
logger.info("createSecret: Successfully invalidated the bearer token of the secret %s and and created the pending version." % arn)
def set_secret(service_client, arn, token, oauth2_token_url):
"""Validate the pending secret with that in Twitter
This method checks wether the bearer token in Twitter is the same as the one in the version with AWSPENDING stage.
Args:
service_client (client): The secrets manager service client
arn (string): The secret ARN or other identifier
token (string): The ClientRequestToken associated with the secret version
oauth2_token_url (string): The Twitter API endopoint to get a bearer token
Raises:
ResourceNotFoundException: If the secret with the specified arn and stage does not exist
ValueError: If the secret is not valid JSON or master credentials could not be used to login to DB
KeyError: If the secret json does not contain the expected keys
"""
# First get the pending version of the bearer token and compare it with that in Twitter
pending_secret_dict = get_secret_dict(service_client, arn, "AWSPENDING")
master_arn = pending_secret_dict['masterarn']
# create bearer token credentials to be passed as authorization string to Twitter
bearer_token_credentials = encode_credentials(service_client, master_arn, "AWSCURRENT")
# get the bearer token from Twitter
bearer_token_from_twitter = get_bearer_token(bearer_token_credentials, oauth2_token_url)
# if the bearer tokens are same, invalidate the bearer token in Twitter
# if not, raise an exception that bearer token in Twitter was changed outside Secrets Manager
if pending_secret_dict['access_token'] == bearer_token_from_twitter:
logger.info("createSecret: Successfully verified the bearer token of arn %s" % arn)
else:
raise ValueError("The bearer token of the Twitter app was changed outside Secrets Manager. Please check.")
def test_secret(service_client, arn, token, tweet_search_url):
"""Test the pending secret by calling a Twitter API
This method tries to use the bearer token in the secret version with AWSPENDING stage and search for tweets
with 'aws secrets manager' string.
Args:
service_client (client): The secrets manager service client
arn (string): The secret ARN or other identifier
token (string): The ClientRequestToken associated with the secret version
Raises:
ResourceNotFoundException: If the secret with the specified arn and stage does not exist
ValueError: If the secret is not valid JSON or pending credentials could not be used to login to the database
KeyError: If the secret json does not contain the expected keys
"""
# First get the pending version of the bearer token and compare it with that in Twitter
pending_secret_dict = get_secret_dict(service_client, arn, "AWSPENDING", token)
# Now verify you can search for tweets using the bearer token
if verify_bearer_token(pending_secret_dict['access_token'], tweet_search_url):
logger.info("testSecret: Successfully authorized with the pending secret in %s." % arn)
return
else:
logger.error("testSecret: Unable to authorize with the pending secret of secret ARN %s" % arn)
raise ValueError("Unable to connect to Twitter with pending secret of secret ARN %s" % arn)
def finish_secret(service_client, arn, token):
"""Finish the rotation by marking the pending secret as current
This method moves the secret from the AWSPENDING stage to the AWSCURRENT stage.
Args:
service_client (client): The secrets manager service client
arn (string): The secret ARN or other identifier
token (string): The ClientRequestToken associated with the secret version
Raises:
ResourceNotFoundException: If the secret with the specified arn and stage does not exist
"""
# First describe the secret to get the current version
metadata = service_client.describe_secret(SecretId=arn)
current_version = None
for version in metadata["VersionIdsToStages"]:
if "AWSCURRENT" in metadata["VersionIdsToStages"][version]:
if version == token:
# The correct version is already marked as current, return
logger.info("finishSecret: Version %s already marked as AWSCURRENT for %s" % (version, arn))
return
current_version = version
break
# Finalize by staging the secret version current
service_client.update_secret_version_stage(SecretId=arn, VersionStage="AWSCURRENT", MoveToVersionId=token, RemoveFromVersionId=current_version)
logger.info("finishSecret: Successfully set AWSCURRENT stage to version %s for secret %s." % (version, arn))
def encode_credentials(service_client, arn, stage):
"""Encodes the Twitter credentials
This helper function encodes the Twitter credentials (consumer_key and consumer_secret)
Args:
service_client (client):The secrets manager service client
arn (string): The secret ARN or other identifier
stage (stage): The stage identifying the secret version
Returns:
encoded_credentials (string): base64 encoded authorization string for Twitter
Raises:
KeyError: If the secret json does not contain the expected keys
"""
required_fields = ['consumer_key','consumer_secret']
master_secret_dict = get_secret_dict(service_client, arn, stage)
for field in required_fields:
if field not in master_secret_dict:
raise KeyError("%s key is missing from the secret JSON" % field)
encoded_credentials = base64.urlsafe_b64encode(
'{}:{}'.format(master_secret_dict['consumer_key'], master_secret_dict['consumer_secret']).encode('ascii')).decode('ascii')
return encoded_credentials
def get_bearer_token(encoded_credentials, oauth2_token_url):
"""Gets a bearer token from Twitter
This helper function retrieves the current bearer token from Twitter, given a set of credentials.
Args:
encoded_credentials (string): Twitter credentials for authentication
oauth2_token_url (string): REST API endpoint to request a bearer token from Twitter
Raises:
KeyError: If the secret json does not contain the expected keys
"""
headers = {
'Authorization': 'Basic {}'.format(encoded_credentials),
'Content-Type': 'application/x-www-form-urlencoded;charset=UTF-8',
}
data = 'grant_type=client_credentials'
response = requests.post(oauth2_token_url, headers=headers, data=data)
response_data = response.json()
if response_data['token_type'] == 'bearer':
bearer_token = response_data['access_token']
return bearer_token
else:
raise RuntimeError('unexpected token type: {}'.format(response_data['token_type']))
def invalidate_bearer_token(oauth2_invalid_token_url, bearer_token_credentials, bearer_token):
"""Invalidates a Bearer Token of a Twitter App
This helper function invalidates a bearer token of a Twitter app.
If successful, it returns the invalidated bearer token, else None
Args:
oauth2_invalid_token_url (string): The Twitter API endpoint to invalidate a bearer token
bearer_token_credentials (string): encoded consumer key and consumer secret to authenticate with Twitter
bearer_token (string): The bearer token to be invalidated
Returns:
invalidated_bearer_token: The invalidated bearer token
Raises:
ResourceNotFoundException: If the secret with the specified arn and stage does not exist
ValueError: If the secret is not valid JSON
KeyError: If the secret json does not contain the expected keys
"""
headers = {
'Authorization': 'Basic {}'.format(bearer_token_credentials),
'Content-Type': 'application/x-www-form-urlencoded;charset=UTF-8',
}
data = 'access_token=' + bearer_token
invalidate_response = requests.post(oauth2_invalid_token_url, headers=headers, data=data)
invalidate_response_data = invalidate_response.json()
if invalidate_response_data:
return
else:
raise RuntimeError('Invalidate bearer token request failed')
def verify_bearer_token(bearer_token, tweet_search_url):
"""Verifies access to Twitter APIs using a bearer token
This helper function verifies that the bearer token is valid by calling Twitter's search/tweets API endpoint
Args:
bearer_token (string): The current bearer token for the application
Returns:
True or False
Raises:
KeyError: If the response of search tweets API call fails
"""
headers = {
'Authorization' : 'Bearer {}'.format(bearer_token),
'Content-Type': 'application/x-www-form-urlencoded;charset=UTF-8',
}
search_results = requests.get(tweet_search_url, headers=headers)
try:
search_results.json()['statuses']
return True
except:
return False
def get_secret_dict(service_client, arn, stage, token=None):
"""Gets the secret dictionary corresponding for the secret arn, stage, and token
This helper function gets credentials for the arn and stage passed in and returns the dictionary by parsing the JSON string
Args:
service_client (client): The secrets manager service client
arn (string): The secret ARN or other identifier
token (string): The ClientRequestToken associated with the secret version, or None if no validation is desired
stage (string): The stage identifying the secret version
Returns:
SecretDictionary: Secret dictionary
Raises:
ResourceNotFoundException: If the secret with the specified arn and stage does not exist
ValueError: If the secret is not valid JSON
"""
# Only do VersionId validation against the stage if a token is passed in
if token:
secret = service_client.get_secret_value(SecretId=arn, VersionId=token, VersionStage=stage)
else:
secret = service_client.get_secret_value(SecretId=arn, VersionStage=stage)
plaintext = secret['SecretString']
# Parse and return the secret JSON string
return json.loads(plaintext)
Here’s what it will look like:
Figure 13: The Python code pasted in the “Function code” section
On the same page, provide the following environment variables:
Note: Resources used in this example are in US East (Ohio) region. If you intend to use another AWS Region, change the SECRETS_MANAGER_ENDPOINT set in the Environment variables to the appropriate region.
You’ve now created a Lambda function that can rotate the bearer token:
Figure 15: The new Lambda function
Before you can configure Secrets Manager to use this Lambda function, you need to update the function policy of the Lambda function. A function policy permits AWS services, such as Secrets Manager, to invoke a Lambda function on behalf of your application. You can attach a Lambda function policy from the AWS Command Line Interface (AWS CLI) or SDK. To attach a function policy, call the add-permission Lambda API from the AWS CLI.
Phase 3: Configure your application to retrieve the bearer token from Secrets Manager
Now that you’ve stored the bearer token in Secrets Manager, update the application to retrieve the bearer token from Secrets Manager instead of hard-coding this information in a configuration file or source code. For this example, I show you how to configure a Python application to retrieve this secret from Secrets Manager.
import config
def no_secrets_manager_sample()
# Get the bearer token from a config file.
Bearer_token = config.bearer_token
# Use the bearer token to authenticate requests to Twitter
Use the sample code from section titled Phase 1 and update the application to retrieve the bearer token from Secrets Manager. The following code sets up the client and retrieves and decrypts the secret Demo/Twitter_bearer_token.
# Use this code snippet in your app.
import boto3
from botocore.exceptions import ClientError
def get_secret():
secret_name = "Demo/Twitter_bearer_token"
endpoint_url = "https://secretsmanager.us-east-2.amazonaws.com"
region_name = "us-east-2"
session = boto3.session.Session()
client = session.client(
service_name='secretsmanager',
region_name=region_name,
endpoint_url=endpoint_url
)
try:
get_secret_value_response = client.get_secret_value(
SecretId=secret_name
)
except ClientError as e:
if e.response['Error']['Code'] == 'ResourceNotFoundException':
print("The requested secret " + secret_name + " was not found")
elif e.response['Error']['Code'] == 'InvalidRequestException':
print("The request was invalid due to:", e)
elif e.response['Error']['Code'] == 'InvalidParameterException':
print("The request had invalid params:", e)
else:
# Decrypted secret using the associated KMS CMK
# Depending on whether the secret was a string or binary, one of these fields will be populated
if 'SecretString' in get_secret_value_response:
secret = get_secret_value_response['SecretString']
else:
binary_secret_data = get_secret_value_response['SecretBinary']
# Your code goes here.
Applications require permissions to access Secrets Manager. My application runs on Amazon EC2 and uses an IAM role to get access to AWS services. I’ll attach the following policy to my IAM role, and you should take a similar action with your IAM role. This policy uses the GetSecretValue action to grant my application permissions to read secrets from Secrets Manager. This policy also uses the resource element to limit my application to read only the Demo/Twitter_bearer_token secret from Secrets Manager. Read the AWS Secrets Manager documentation to understand the minimum IAM permissions required to retrieve a secret.
{
"Version": "2012-10-17",
"Statement": {
"Sid": "RetrieveBearerToken",
"Effect": "Allow",
"Action": "secretsmanager:GetSecretValue",
"Resource": Input ARN of the secret Demo/Twitter_bearer_token here
}
}
Note: To improve the resiliency of your applications, associate your application with two API keys/bearer tokens. This is a higher availability option because you can continue to use one bearer token while Secrets Manager rotates the other token. Read the AWS documentation to learn how AWS Secrets Manager rotates your secrets.
Phase 4: Enable and verify rotation
Now that you’ve stored the secret in Secrets Manager and created a Lambda function to rotate this secret, configure Secrets Manager to rotate the secret Demo/Twitter_bearer_token.
From the Secrets Manager console, go to the list of secrets and choose the secret you created in the first step (in my example, this is named Demo/Twitter_bearer_token).
Scroll to Rotation configuration, and then select Edit rotation.
Figure 16: Select the “Edit rotation” button
To enable rotation, select Enable automatic rotation, and then choose how frequently you want Secrets Manager to rotate this secret. For this example, I set the rotation interval to 30 days. I also choose the rotation Lambda function, Lambda_Rotate_Bearer_Token, from the drop-down list.
Figure 17: “Edit rotation configuration” options
The banner on the next screen confirms that I have successfully configured rotation and the first rotation is in progress, which enables you to verify that rotation is functioning as expected. Secrets Manager will rotate this credential automatically every 30 days.
Figure 18: Confirmation notice
Summary
In this post, I showed you how to configure Secrets Manager to manage and rotate an API key and bearer token used by applications to authenticate and retrieve information from Twitter. You can use the steps described in this blog to manage and rotate other API keys, as well.
Secrets Manager helps you protect access to your applications, services, and IT resources without the upfront investment and on-going maintenance costs of operating your own secrets management infrastructure. To get started, open the Secrets Manager console. To learn more, read the Secrets Manager documentation.
If you have comments about this post, submit them in the Comments section below. If you have questions about anything in this post, start a new thread on the Secrets Manager forum or contact AWS Support.
Want more AWS Security news? Follow us on Twitter.
Hey folks, Rob here! It’s the last Thursday of the month, and that means it’s time for a brand-new The MagPi. Issue 70 is all about home automation using your favourite microcomputer, the Raspberry Pi.
Home automation in this month’s The MagPi!
Raspberry Pi home automation
We think home automation is an excellent use of the Raspberry Pi, hiding it around your house and letting it power your lights and doorbells and…fish tanks? We show you how to do all of that, and give you some excellent tips on how to add even more automation to your home in our ten-page cover feature.
Upcycle your life
Our other big feature this issue covers upcycling, the hot trend of taking old electronics and making them better than new with some custom code and a tactically placed Raspberry Pi. For this feature, we had a chat with Martin Mander, upcycler extraordinaire, to find out his top tips for hacking your old hardware.
Upcycling is a lot of fun
But wait, there’s more!
If for some reason you want even more content, you’re in luck! We have some fun tutorials for you to try, like creating a theremin and turning a Babbage into an IoT nanny cam. We also continue our quest to make a video game in C++. Our project showcase is headlined by the Teslonda on page 28, a Honda/Tesla car hybrid that is just wonderful.
We review PiBorg’s latest robot
All this comes with our definitive reviews and the community section where we celebrate you, our amazing community! You’re all good beans
An amazing, and practical, Raspberry Pi project
Get The MagPi 70
Issue 70 is available today from WHSmith, Tesco, Sainsbury’s, and Asda. If you live in the US, head over to your local Barnes & Noble or Micro Center in the next few days for a print copy. You can also get the new issue online from our store, or digitally via our Android and iOS apps. And don’t forget, there’s always the free PDF as well.
New subscription offer!
Want to support the Raspberry Pi Foundation and the magazine? We’ve launched a new way to subscribe to the print version of The MagPi: you can now take out a monthly £4 subscription to the magazine, effectively creating a rolling pre-order system that saves you money on each issue.
You can also take out a twelve-month print subscription and get a Pi Zero W plus case and adapter cables absolutely free! This offer does not currently have an end date.
What do I do with a Mac that still has personal data on it? Do I take out the disk drive and smash it? Do I sweep it with a really strong magnet? Is there a difference in how I handle a hard drive (HDD) versus a solid-state drive (SSD)? Well, taking a sledgehammer or projectile weapon to your old machine is certainly one way to make the data irretrievable, and it can be enormously cathartic as long as you follow appropriate safety and disposal protocols. But there are far less destructive ways to make sure your data is gone for good. Let me introduce you to secure erasing.
Which Type of Drive Do You Have?
Before we start, you need to know whether you have a HDD or a SSD. To find out, or at least to make sure, you click on the Apple menu and select “About this Mac.” Once there, select the “Storage” tab to see which type of drive is in your system.
The first example, below, shows a SATA Disk (HDD) in the system.
In the next case, we see we have a Solid State SATA Drive (SSD), plus a Mac SuperDrive.
The third screen shot shows an SSD, as well. In this case it’s called “Flash Storage.”
Make Sure You Have a Backup
Before you get started, you’ll want to make sure that any important data on your hard drive has moved somewhere else. OS X’s built-in Time Machine backup software is a good start, especially when paired with Backblaze. You can learn more about using Time Machine in our Mac Backup Guide.
With a local backup copy in hand and secure cloud storage, you know your data is always safe no matter what happens.
Once you’ve verified your data is backed up, roll up your sleeves and get to work. The key is OS X Recovery — a special part of the Mac operating system since OS X 10.7 “Lion.”
How to Wipe a Mac Hard Disk Drive (HDD)
NOTE: If you’re interested in wiping an SSD, see below.
Make sure your Mac is turned off.
Press the power button.
Immediately hold down the command and R keys.
Wait until the Apple logo appears.
Select “Disk Utility” from the OS X Utilities list. Click Continue.
Select the disk you’d like to erase by clicking on it in the sidebar.
Click the Erase button.
Click the Security Options button.
The Security Options window includes a slider that enables you to determine how thoroughly you want to erase your hard drive.
There are four notches to that Security Options slider. “Fastest” is quick but insecure — data could potentially be rebuilt using a file recovery app. Moving that slider to the right introduces progressively more secure erasing. Disk Utility’s most secure level erases the information used to access the files on your disk, then writes zeroes across the disk surface seven times to help remove any trace of what was there. This setting conforms to the DoD 5220.22-M specification.
Once you’ve selected the level of secure erasing you’re comfortable with, click the OK button.
Click the Erase button to begin. Bear in mind that the more secure method you select, the longer it will take. The most secure methods can add hours to the process.
Once it’s done, the Mac’s hard drive will be clean as a whistle and ready for its next adventure: a fresh installation of OS X, being donated to a relative or a local charity, or just sent to an e-waste facility. Of course you can still drill a hole in your disk or smash it with a sledgehammer if it makes you happy, but now you know how to wipe the data from your old computer with much less ruckus.
The above instructions apply to older Macintoshes with HDDs. What do you do if you have an SSD?
Securely Erasing SSDs, and Why Not To
Most new Macs ship with solid state drives (SSDs). Only the iMac and Mac mini ship with regular hard drives anymore, and even those are available in pure SSD variants if you want.
If your Mac comes equipped with an SSD, Apple’s Disk Utility software won’t actually let you zero the hard drive.
Wait, what?
In a tech note posted to Apple’s own online knowledgebase, Apple explains that you don’t need to securely erase your Mac’s SSD:
With an SSD drive, Secure Erase and Erasing Free Space are not available in Disk Utility. These options are not needed for an SSD drive because a standard erase makes it difficult to recover data from an SSD.
In fact, some folks will tell you not to zero out the data on an SSD, since it can cause wear and tear on the memory cells that, over time, can affect its reliability. I don’t think that’s nearly as big an issue as it used to be — SSD reliability and longevity has improved.
If “Standard Erase” doesn’t quite make you feel comfortable that your data can’t be recovered, there are a couple of options.
FileVault Keeps Your Data Safe
One way to make sure that your SSD’s data remains secure is to use FileVault. FileVault is whole-disk encryption for the Mac. With FileVault engaged, you need a password to access the information on your hard drive. Without it, that data is encrypted.
There’s one potential downside of FileVault — if you lose your password or the encryption key, you’re screwed: You’re not getting your data back any time soon. Based on my experience working at a Mac repair shop, losing a FileVault key happens more frequently than it should.
When you first set up a new Mac, you’re given the option of turning FileVault on. If you don’t do it then, you can turn on FileVault at any time by clicking on your Mac’s System Preferences, clicking on Security & Privacy, and clicking on the FileVault tab. Be warned, however, that the initial encryption process can take hours, as will decryption if you ever need to turn FileVault off.
With FileVault turned on, you can restart your Mac into its Recovery System (by restarting the Mac while holding down the command and R keys) and erase the hard drive using Disk Utility, once you’ve unlocked it (by selecting the disk, clicking the File menu, and clicking Unlock). That deletes the FileVault key, which means any data on the drive is useless.
FileVault doesn’t impact the performance of most modern Macs, though I’d suggest only using it if your Mac has an SSD, not a conventional hard disk drive.
Securely Erasing Free Space on Your SSD
If you don’t want to take Apple’s word for it, if you’re not using FileVault, or if you just want to, there is a way to securely erase free space on your SSD. It’s a little more involved but it works.
Before we get into the nitty-gritty, let me state for the record that this really isn’t necessary to do, which is why Apple’s made it so hard to do. But if you’re set on it, you’ll need to use Apple’s Terminal app. Terminal provides you with command line interface access to the OS X operating system. Terminal lives in the Utilities folder, but you can access Terminal from the Mac’s Recovery System, as well. Once your Mac has booted into the Recovery partition, click the Utilities menu and select Terminal to launch it.
From a Terminal command line, type:
diskutil secureErase freespace VALUE /Volumes/DRIVE
That tells your Mac to securely erase the free space on your SSD. You’ll need to change VALUE to a number between 0 and 4. 0 is a single-pass run of zeroes; 1 is a single-pass run of random numbers; 2 is a 7-pass erase; 3 is a 35-pass erase; and 4 is a 3-pass erase. DRIVE should be changed to the name of your hard drive. To run a 7-pass erase of your SSD drive in “JohnB-Macbook”, you would enter the following:
And remember, if you used a space in the name of your Mac’s hard drive, you need to insert a leading backslash before the space. For example, to run a 35-pass erase on a hard drive called “Macintosh HD” you enter the following:
diskutil secureErase freespace 3 /Volumes/Macintosh\ HD
Something to remember is that the more extensive the erase procedure, the longer it will take.
When Erasing is Not Enough — How to Destroy a Drive
If you absolutely, positively need to be sure that all the data on a drive is irretrievable, see this Scientific American article (with contributions by Gleb Budman, Backblaze CEO), How to Destroy a Hard Drive — Permanently.
This post is courtesy of Alan Protasio, Software Development Engineer, Amazon Web Services
Just like compute and storage, messaging is a fundamental building block of enterprise applications. Message brokers (aka “message-oriented middleware”) enable different software systems, often written in different languages, on different platforms, running in different locations, to communicate and exchange information. Mission-critical applications, such as CRM and ERP, rely on message brokers to work.
A common performance consideration for customers deploying a message broker in a production environment is the throughput of the system, measured as messages per second. This is important to know so that application environments (hosts, threads, memory, etc.) can be configured correctly.
In this post, we demonstrate how to measure the throughput for Amazon MQ, a new managed message broker service for ActiveMQ, using JMS Benchmark. It should take between 15–20 minutes to set up the environment and an hour to run the benchmark. We also provide some tips on how to configure Amazon MQ for optimal throughput.
Benchmarking throughput for Amazon MQ
ActiveMQ can be used for a number of use cases. These use cases can range from simple fire and forget tasks (that is, asynchronous processing), low-latency request-reply patterns, to buffering requests before they are persisted to a database.
The throughput of Amazon MQ is largely dependent on the use case. For example, if you have non-critical workloads such as gathering click events for a non-business-critical portal, you can use ActiveMQ in a non-persistent mode and get extremely high throughput with Amazon MQ.
On the flip side, if you have a critical workload where durability is extremely important (meaning that you can’t lose a message), then you are bound by the I/O capacity of your underlying persistence store. We recommend using mq.m4.large for the best results. The mq.t2.micro instance type is intended for product evaluation. Performance is limited, due to the lower memory and burstable CPU performance.
Tip: To improve your throughput with Amazon MQ, make sure that you have consumers processing messaging as fast as (or faster than) your producers are pushing messages.
Because it’s impossible to talk about how the broker (ActiveMQ) behaves for each and every use case, we walk through how to set up your own benchmark for Amazon MQ using our favorite open-source benchmarking tool: JMS Benchmark. We are fans of the JMS Benchmark suite because it’s easy to set up and deploy, and comes with a built-in visualizer of the results.
Non-Persistent Scenarios – Queue latency as you scale producer throughput
Getting started
At the time of publication, you can create an mq.m4.large single-instance broker for testing for $0.30 per hour (US pricing).
Step 2 – Create an EC2 instance to run your benchmark Launch the EC2 instance using Step 1: Launch an Instance. We recommend choosing the m5.large instance type.
Step 3 – Configure the security groups Make sure that all the security groups are correctly configured to let the traffic flow between the EC2 instance and your broker.
From the broker list, choose the name of your broker (for example, MyBroker)
In the Details section, under Security and network, choose the name of your security group or choose the expand icon ( ).
From the security group list, choose your security group.
At the bottom of the page, choose Inbound, Edit.
In the Edit inbound rules dialog box, add a role to allow traffic between your instance and the broker: • Choose Add Rule. • For Type, choose Custom TCP. • For Port Range, type the ActiveMQ SSL port (61617). • For Source, leave Custom selected and then type the security group of your EC2 instance. • Choose Save.
Your broker can now accept the connection from your EC2 instance.
Step 4 – Run the benchmark Connect to your EC2 instance using SSH and run the following commands:
After the benchmark finishes, you can find the results in the ~/reports directory. As you may notice, the performance of ActiveMQ varies based on the number of consumers, producers, destinations, and message size.
Amazon MQ architecture
The last bit that’s important to know so that you can better understand the results of the benchmark is how Amazon MQ is architected.
Amazon MQ is architected to be highly available (HA) and durable. For HA, we recommend using the multi-AZ option. After a message is sent to Amazon MQ in persistent mode, the message is written to the highly durable message store that replicates the data across multiple nodes in multiple Availability Zones. Because of this replication, for some use cases you may see a reduction in throughput as you migrate to Amazon MQ. Customers have told us they appreciate the benefits of message replication as it helps protect durability even in the face of the loss of an Availability Zone.
Conclusion
We hope this gives you an idea of how Amazon MQ performs. We encourage you to run tests to simulate your own use cases.
To learn more, see the Amazon MQ website. You can try Amazon MQ for free with the AWS Free Tier, which includes up to 750 hours of a single-instance mq.t2.micro broker and up to 1 GB of storage per month for one year.
The adoption of Apache Spark has increased significantly over the past few years, and running Spark-based application pipelines is the new normal. Spark jobs that are in an ETL (extract, transform, and load) pipeline have different requirements—you must handle dependencies in the jobs, maintain order during executions, and run multiple jobs in parallel. In most of these cases, you can use workflow scheduler tools like Apache Oozie, Apache Airflow, and even Cron to fulfill these requirements.
Apache Oozie is a widely used workflow scheduler system for Hadoop-based jobs. However, its limited UI capabilities, lack of integration with other services, and heavy XML dependency might not be suitable for some users. On the other hand, Apache Airflow comes with a lot of neat features, along with powerful UI and monitoring capabilities and integration with several AWS and third-party services. However, with Airflow, you do need to provision and manage the Airflow server. The Cron utility is a powerful job scheduler. But it doesn’t give you much visibility into the job details, and creating a workflow using Cron jobs can be challenging.
What if you have a simple use case, in which you want to run a few Spark jobs in a specific order, but you don’t want to spend time orchestrating those jobs or maintaining a separate application? You can do that today in a serverless fashion using AWS Step Functions. You can create the entire workflow in AWS Step Functions and interact with Spark on Amazon EMR through Apache Livy.
In this post, I walk you through a list of steps to orchestrate a serverless Spark-based ETL pipeline using AWS Step Functions and Apache Livy.
Input data
For the source data for this post, I use the New York City Taxi and Limousine Commission (TLC) trip record data. For a description of the data, see this detailed dictionary of the taxi data. In this example, we’ll work mainly with the following three columns for the Spark jobs.
Column name
Column description
RateCodeID
Represents the rate code in effect at the end of the trip (for example, 1 for standard rate, 2 for JFK airport, 3 for Newark airport, and so on).
FareAmount
Represents the time-and-distance fare calculated by the meter.
TripDistance
Represents the elapsed trip distance in miles reported by the taxi meter.
The trip data is in comma-separated values (CSV) format with the first row as a header. To shorten the Spark execution time, I trimmed the large input data to only 20,000 rows. During the deployment phase, the input file tripdata.csv is stored in Amazon S3 in the <<your-bucket>>/emr-step-functions/input/ folder.
The following image shows a sample of the trip data:
Solution overview
The next few sections describe how Spark jobs are created for this solution, how you can interact with Spark using Apache Livy, and how you can use AWS Step Functions to create orchestrations for these Spark applications.
At a high level, the solution includes the following steps:
Trigger the AWS Step Function state machine by passing the input file path.
The first stage in the state machine triggers an AWS Lambda
The Lambda function interacts with Apache Spark running on Amazon EMR using Apache Livy, and submits a Spark job.
The state machine waits a few seconds before checking the Spark job status.
Based on the job status, the state machine moves to the success or failure state.
Subsequent Spark jobs are submitted using the same approach.
The state machine waits a few seconds for the job to finish.
The job finishes, and the state machine updates with its final status.
Let’s take a look at the Spark application that is used for this solution.
Spark jobs
For this example, I built a Spark jar named spark-taxi.jar. It has two different Spark applications:
MilesPerRateCode – The first job that runs on the Amazon EMR cluster. This job reads the trip data from an input source and computes the total trip distance for each rate code. The output of this job consists of two columns and is stored in Apache Parquet format in the output path.
The following are the expected output columns:
rate_code – Represents the rate code for the trip.
total_distance – Represents the total trip distance for that rate code (for example, sum(trip_distance)).
RateCodeStatus – The second job that runs on the EMR cluster, but only if the first job finishes successfully. This job depends on two different input sets:
csv – The same trip data that is used for the first Spark job.
miles-per-rate – The output of the first job.
This job first reads the tripdata.csv file and aggregates the fare_amount by the rate_code. After this point, you have two different datasets, both aggregated by rate_code. Finally, the job uses the rate_code field to join two datasets and output the entire rate code status in a single CSV file.
The output columns are as follows:
rate_code_id – Represents the rate code type.
total_distance – Derived from first Spark job and represents the total trip distance.
total_fare_amount – A new field that is generated during the second Spark application, representing the total fare amount by the rate code type.
Note that in this case, you don’t need to run two different Spark jobs to generate that output. The goal of setting up the jobs in this way is just to create a dependency between the two jobs and use them within AWS Step Functions.
Both Spark applications take one input argument called rootPath. It’s the S3 location where the Spark job is stored along with input and output data. Here is a sample of the final output:
The next section discusses how you can use Apache Livy to interact with Spark applications that are running on Amazon EMR.
Using Apache Livy to interact with Apache Spark
Apache Livy provides a REST interface to interact with Spark running on an EMR cluster. Livy is included in Amazon EMR release version 5.9.0 and later. In this post, I use Livy to submit Spark jobs and retrieve job status. When Amazon EMR is launched with Livy installed, the EMR master node becomes the endpoint for Livy, and it starts listening on port 8998 by default. Livy provides APIs to interact with Spark.
Let’s look at a couple of examples how you can interact with Spark running on Amazon EMR using Livy.
To list active running jobs, you can execute the following from the EMR master node:
curl localhost:8998/sessions
If you want to do the same from a remote instance, just change localhost to the EMR hostname, as in the following (port 8998 must be open to that remote instance through the security group):
Through Spark submit, you can pass multiple arguments for the Spark job and Spark configuration settings. You can also do that using Livy, by passing the S3 path through the args parameter, as shown following:
curl -X POST – data '{"file": "s3://<<bucket-location>>/spark.jar", "className": "com.example.SparkApp", “args”: [“s3://bucket-path”]}' -H "Content-Type: application/json" http://ec2-xx-xx-xx-xx.compute-1.amazonaws.com:8998/batches
All Apache Livy REST calls return a response as JSON, as shown in the following image:
If you want to pretty-print that JSON response, you can pipe command with Python’s JSON tool as follows:
For a detailed list of Livy APIs, see the Apache Livy REST API page. This post uses GET /batches and POST /batches.
In the next section, you create a state machine and orchestrate Spark applications using AWS Step Functions.
Using AWS Step Functions to create a Spark job workflow
AWS Step Functions automatically triggers and tracks each step and retries when it encounters errors. So your application executes in order and as expected every time. To create a Spark job workflow using AWS Step Functions, you first create a Lambda state machine using different types of states to create the entire workflow.
First, you use the Task state—a simple state in AWS Step Functions that performs a single unit of work. You also use the Wait state to delay the state machine from continuing for a specified time. Later, you use the Choice state to add branching logic to a state machine.
The following is a quick summary of how to use different states in the state machine to create the Spark ETL pipeline:
Task state – Invokes a Lambda function. The first Task state submits the Spark job on Amazon EMR, and the next Task state is used to retrieve the previous Spark job status.
Wait state – Pauses the state machine until a job completes execution.
Choice state – Each Spark job execution can return a failure, an error, or a success state So, in the state machine, you use the Choice state to create a rule that specifies the next action or step based on the success or failure of the previous step.
Here is one of my Task states, MilesPerRateCode, which simply submits a Spark job:
"MilesPerRate Job": {
"Type": "Task",
"Resource":"arn:aws:lambda:us-east-1:xxxxxx:function:blog-miles-per-rate-job-submit-function",
"ResultPath": "$.jobId",
"Next": "Wait for MilesPerRate job to complete"
}
This Task state configuration specifies the Lambda function to execute. Inside the Lambda function, it submits a Spark job through Livy using Livy’s POST API. Using ResultPath, it tells the state machine where to place the result of the executing task. As discussed in the previous section, Spark submit returns the session ID, which is captured with $.jobId and used in a later state.
The following code section shows the Lambda function, which is used to submit the MilesPerRateCode job. It uses the Python request library to submit a POST against the Livy endpoint hosted on Amazon EMR and passes the required parameters in JSON format through payload. It then parses the response, grabs id from the response, and returns it. The Next field tells the state machine which state to go to next.
Just like in the MilesPerRate job, another state submits the RateCodeStatus job, but it executes only when all previous jobs have completed successfully.
Here is the Task state in the state machine that checks the Spark job status:
Just like other states, the preceding Task executes a Lambda function, captures the result (represented by jobStatus), and passes it to the next state. The following is the Lambda function that checks the Spark job status based on a given session ID:
In the Choice state, it checks the Spark job status value, compares it with a predefined state status, and transitions the state based on the result. For example, if the status is success, move to the next state (RateCodeJobStatus job), and if it is dead, move to the MilesPerRate job failed state.
To set up this entire solution, you need to create a few AWS resources. To make it easier, I have created an AWS CloudFormation template. This template creates all the required AWS resources and configures all the resources that are needed to create a Spark-based ETL pipeline on AWS Step Functions.
This CloudFormation template requires you to pass the following four parameters during initiation.
Parameter
Description
ClusterSubnetID
The subnet where the Amazon EMR cluster is deployed and Lambda is configured to talk to this subnet.
KeyName
The name of the existing EC2 key pair to access the Amazon EMR cluster.
VPCID
The ID of the virtual private cloud (VPC) where the EMR cluster is deployed and Lambda is configured to talk to this VPC.
S3RootPath
The Amazon S3 path where all required files (input file, Spark job, and so on) are stored and the resulting data is written.
IMPORTANT: These templates are designed only to show how you can create a Spark-based ETL pipeline on AWS Step Functions using Apache Livy. They are not intended for production use without modification. And if you try this solution outside of the us-east-1 Region, download the necessary files from s3://aws-data-analytics-blog/emr-step-functions, upload the files to the buckets in your Region, edit the script as appropriate, and then run it.
To launch the CloudFormation stack, choose Launch Stack:
Launching this stack creates the following list of AWS resources.
Logical ID
Resource Type
Description
StepFunctionsStateExecutionRole
IAM role
IAM role to execute the state machine and have a trust relationship with the states service.
SparkETLStateMachine
AWS Step Functions state machine
State machine in AWS Step Functions for the Spark ETL workflow.
LambdaSecurityGroup
Amazon EC2 security group
Security group that is used for the Lambda function to call the Livy API.
RateCodeStatusJobSubmitFunction
AWS Lambda function
Lambda function to submit the RateCodeStatus job.
MilesPerRateJobSubmitFunction
AWS Lambda function
Lambda function to submit the MilesPerRate job.
SparkJobStatusFunction
AWS Lambda function
Lambda function to check the Spark job status.
LambdaStateMachineRole
IAM role
IAM role for all Lambda functions to use the lambda trust relationship.
EMRCluster
Amazon EMR cluster
EMR cluster where Livy is running and where the job is placed.
During the AWS CloudFormation deployment phase, it sets up S3 paths for input and output. Input files are stored in the <<s3-root-path>>/emr-step-functions/input/ path, whereas spark-taxi.jar is copied under <<s3-root-path>>/emr-step-functions/.
The following screenshot shows how the S3 paths are configured after deployment. In this example, I passed a bucket that I created in the AWS account s3://tm-app-demos for the S3 root path.
If the CloudFormation template completed successfully, you will see Spark-ETL-State-Machine in the AWS Step Functions dashboard, as follows:
Choose the Spark-ETL-State-Machine state machine to take a look at this implementation. The AWS CloudFormation template built the entire state machine along with its dependent Lambda functions, which are now ready to be executed.
On the dashboard, choose the newly created state machine, and then choose New execution to initiate the state machine. It asks you to pass input in JSON format. This input goes to the first state MilesPerRate Job, which eventually executes the Lambda function blog-miles-per-rate-job-submit-function.
Pass the S3 root path as input:
{
“rootPath”: “s3://tm-app-demos”
}
Then choose Start Execution:
The rootPath value is the same value that was passed when creating the CloudFormation stack. It can be an S3 bucket location or a bucket with prefixes, but it should be the same value that is used for AWS CloudFormation. This value tells the state machine where it can find the Spark jar and input file, and where it will write output files. After the state machine starts, each state/task is executed based on its definition in the state machine.
At a high level, the following represents the flow of events:
Execute the first Spark job, MilesPerRate.
The Spark job reads the input file from the location <<rootPath>>/emr-step-functions/input/tripdata.csv. If the job finishes successfully, it writes the output data to <<rootPath>>/emr-step-functions/miles-per-rate.
If the Spark job fails, it transitions to the error state MilesPerRate job failed, and the state machine stops. If the Spark job finishes successfully, it transitions to the RateCodeStatus Job state, and the second Spark job is executed.
If the second Spark job fails, it transitions to the error state RateCodeStatus job failed, and the state machine stops with the Failed status.
If this Spark job completes successfully, it writes the final output data to the <<rootPath>>/emr-step-functions/rate-code-status/ It also transitions the RateCodeStatus job finished state, and the state machine ends its execution with the Success status.
This following screenshot shows a successfully completed Spark ETL state machine:
The right side of the state machine diagram shows the details of individual states with their input and output.
When you execute the state machine for the second time, it fails because the S3 path already exists. The state machine turns red and stops at MilePerRate job failed. The following image represents that failed execution of the state machine:
You can also check your Spark application status and logs by going to the Amazon EMR console and viewing the Application history tab:
I hope this walkthrough paints a picture of how you can create a serverless solution for orchestrating Spark jobs on Amazon EMR using AWS Step Functions and Apache Livy. In the next section, I share some ideas for making this solution even more elegant.
Next steps
The goal of this post is to show a simple example that uses AWS Step Functions to create an orchestration for Spark-based jobs in a serverless fashion. To make this solution robust and production ready, you can explore the following options:
In this example, I manually initiated the state machine by passing the rootPath as input. You can instead trigger the state machine automatically. To run the ETL pipeline as soon as the files arrive in your S3 bucket, you can pass the new file path to the state machine. Because CloudWatch Events supports AWS Step Functions as a target, you can create a CloudWatch rule for an S3 event. You can then set AWS Step Functions as a target and pass the new file path to your state machine. You’re all set!
You can also improve this solution by adding an alerting mechanism in case of failures. To do this, create a Lambda function that sends an alert email and assigns that Lambda function to a Fail That way, when any part of your state fails, it triggers an email and notifies the user.
If you want to submit multiple Spark jobs in parallel, you can use the Parallel state type in AWS Step Functions. The Parallel state is used to create parallel branches of execution in your state machine.
With Lambda and AWS Step Functions, you can create a very robust serverless orchestration for your big data workload.
Cleaning up
When you’ve finished testing this solution, remember to clean up all those AWS resources that you created using AWS CloudFormation. Use the AWS CloudFormation console or AWS CLI to delete the stack named Blog-Spark-ETL-Step-Functions.
Summary
In this post, I showed you how to use AWS Step Functions to orchestrate your Spark jobs that are running on Amazon EMR. You used Apache Livy to submit jobs to Spark from a Lambda function and created a workflow for your Spark jobs, maintaining a specific order for job execution and triggering different AWS events based on your job’s outcome. Go ahead—give this solution a try, and share your experience with us!
Tanzir Musabbir is an EMR Specialist Solutions Architect with AWS. He is an early adopter of open source Big Data technologies. At AWS, he works with our customers to provide them architectural guidance for running analytics solutions on Amazon EMR, Amazon Athena & AWS Glue. Tanzir is a big Real Madrid fan and he loves to travel in his free time.
As we shoot way past 500 petabytes of data stored, we need a lot of helping hands in the data center to keep those hard drives spinning! We’ve been hiring quite a lot, and our latest addition is Jack. Lets learn a bit more about him, shall we?
What is your Backblaze Title? Data Center Tech
Where are you originally from? Walnut Creek, CA until 7th grade when the family moved to Durango, Colorado.
What attracted you to Backblaze? I had heard about how cool the Backblaze community is and have always been fascinated by technology.
What do you expect to learn while being at Backblaze? I expect to learn a lot about how our data centers run and all of the hardware behind it.
Where else have you worked? Garrhs HVAC as an HVAC Installer and then Durango Electrical as a Low Volt Technician.
Where did you go to school? Durango High School and then Montana State University.
What’s your dream job? I would love to be a driver for the Audi Sport. Race cars are so much fun!
Favorite place you’ve traveled? Iceland has definitely been my favorite so far.
Favorite hobby? Video games.
Of what achievement are you most proud? Getting my Eagle Scout badge was a tough, but rewarding experience that I will always cherish.
Star Trek or Star Wars? Star Wars.
Coke or Pepsi? Coke…I know, it’s bad.
Favorite food? Thai food.
Why do you like certain things? I tend to warm up to things the more time I spend around them, although I never really know until it happens.
Anything else you’d like to tell us? I’m a friendly car guy who will always be in love with my European cars and I really enjoy the Backblaze community!
We’re happy you joined us Out West! Welcome aboard Jack!
Thanks to Greg Eppel, Sr. Solutions Architect, Microsoft Platform for this great blog that describes how to create a custom CodeBuild build environment for the .NET Framework. — AWS CodeBuild is a fully managed build service that compiles source code, runs tests, and produces software packages that are ready to deploy. CodeBuild provides curated build environments for programming languages and runtimes such as Android, Go, Java, Node.js, PHP, Python, Ruby, and Docker. CodeBuild now supports builds for the Microsoft Windows Server platform, including a prepackaged build environment for .NET Core on Windows. If your application uses the .NET Framework, you will need to use a custom Docker image to create a custom build environment that includes the Microsoft proprietary Framework Class Libraries. For information about why this step is required, see our FAQs. In this post, I’ll show you how to create a custom build environment for .NET Framework applications and walk you through the steps to configure CodeBuild to use this environment.
Build environments are Docker images that include a complete file system with everything required to build and test your project. To use a custom build environment in a CodeBuild project, you build a container image for your platform that contains your build tools, push it to a Docker container registry such as Amazon Elastic Container Registry (Amazon ECR), and reference it in the project configuration. When it builds your application, CodeBuild retrieves the Docker image from the container registry specified in the project configuration and uses the environment to compile your source code, run your tests, and package your application.
Step 1: Launch EC2 Windows Server 2016 with Containers
In the Amazon EC2 console, in your region, launch an Amazon EC2 instance from a Microsoft Windows Server 2016 Base with Containers AMI.
Increase disk space on the boot volume to at least 50 GB to account for the larger size of containers required to install and run Visual Studio Build Tools.
Run the following command in that directory. This process can take a while. It depends on the size of EC2 instance you launched. In my tests, a t2.2xlarge takes less than 30 minutes to build the image and produces an approximately 15 GB image.
docker build -t buildtools2017:latest -m 2GB .
Run the following command to test the container and start a command shell with all the developer environment variables:
docker run -it buildtools2017
Create a repository in the Amazon ECS console. For the repository name, type buildtools2017. Choose Next step and then complete the remaining steps.
Execute the following command to generate authentication details for our registry to the local Docker engine. Make sure you have permissions to the Amazon ECR registry before you execute the command.
aws ecr get-login
In the same command prompt window, copy and paste the following commands:
In the CodeCommit console, create a repository named DotNetFrameworkSampleApp. On the Configure email notifications page, choose Skip.
Clone a .NET Framework Docker sample application from GitHub. The repository includes a sample ASP.NET Framework that we’ll use to demonstrate our custom build environment.On the EC2 instance, open a command prompt and execute the following commands:
Navigate to the CodeCommit repository and confirm that the files you just pushed are there.
Step 4: Configure build spec
To build your .NET Framework application with CodeBuild you use a build spec, which is a collection of build commands and related settings, in YAML format, that AWS CodeBuild can use to run a build. You can include a build spec as part of the source code or you can define a build spec when you create a build project. In this example, I include a build spec as part of the source code.
In the root directory of your source directory, create a YAML file named buildspec.yml.
At this point, we have a Docker image with Visual Studio Build Tools installed and stored in the Amazon ECR registry. We also have a sample ASP.NET Framework application in a CodeCommit repository. Now we are going to set up CodeBuild to build the ASP.NET Framework application.
In the Amazon ECR console, choose the repository that was pushed earlier with the docker push command. On the Permissions tab, choose Add.
For Source Provider, choose AWS CodeCommit and then choose the called DotNetFrameworkSampleApp repository.
For Environment Image, choose Specify a Docker image.
For Environment type, choose Windows.
For Custom image type, choose Amazon ECR.
For Amazon ECR repository, choose the Docker image with the Visual Studio Build Tools installed, buildtools2017. Your configuration should look like the image below:
Choose Continue and then Save and Build to create your CodeBuild project and start your first build. You can monitor the status of the build in the console. You can also configure notifications that will notify subscribers whenever builds succeed, fail, go from one phase to another, or any combination of these events.
Summary
CodeBuild supports a number of platforms and languages out of the box. By using custom build environments, it can be extended to other runtimes. In this post, I showed you how to build a .NET Framework environment on a Windows container and demonstrated how to use it to build .NET Framework applications in CodeBuild.
We’re excited to see how customers extend and use CodeBuild to enable continuous integration and continuous delivery for their Windows applications. Feel free to share what you’ve learned extending CodeBuild for your own projects. Just leave questions or suggestions in the comments.
This post courtesy of Thiago Morais, AWS Solutions Architect
When you build web applications or expose any data externally, you probably look for a platform where you can build highly scalable, secure, and robust REST APIs. As APIs are publicly exposed, there are a number of best practices for providing a secure mechanism to consumers using your API.
Amazon API Gateway handles all the tasks involved in accepting and processing up to hundreds of thousands of concurrent API calls, including traffic management, authorization and access control, monitoring, and API version management.
In this post, I show you how to take advantage of the regional API endpoint feature in API Gateway, so that you can create your own Amazon CloudFront distribution and secure your API using AWS WAF.
AWS WAF is a web application firewall that helps protect your web applications from common web exploits that could affect application availability, compromise security, or consume excessive resources.
As you make your APIs publicly available, you are exposed to attackers trying to exploit your services in several ways. The AWS security team published a whitepaper solution using AWS WAF, How to Mitigate OWASP’s Top 10 Web Application Vulnerabilities.
Regional API endpoints
Edge-optimized APIs are endpoints that are accessed through a CloudFront distribution created and managed by API Gateway. Before the launch of regional API endpoints, this was the default option when creating APIs using API Gateway. It primarily helped to reduce latency for API consumers that were located in different geographical locations than your API.
When API requests predominantly originate from an Amazon EC2 instance or other services within the same AWS Region as the API is deployed, a regional API endpoint typically lowers the latency of connections. It is recommended for such scenarios.
For better control around caching strategies, customers can use their own CloudFront distribution for regional APIs. They also have the ability to use AWS WAF protection, as I describe in this post.
Edge-optimized API endpoint
The following diagram is an illustrated example of the edge-optimized API endpoint where your API clients access your API through a CloudFront distribution created and managed by API Gateway.
Regional API endpoint
For the regional API endpoint, your customers access your API from the same Region in which your REST API is deployed. This helps you to reduce request latency and particularly allows you to add your own content delivery network, as needed.
Walkthrough
In this section, you implement the following steps:
Attach the web ACL to the CloudFront distribution.
Test AWS WAF protection.
Create the regional API
For this walkthrough, use an existing PetStore API. All new APIs launch by default as the regional endpoint type. To change the endpoint type for your existing API, choose the cog icon on the top right corner:
After you have created the PetStore API on your account, deploy a stage called “prod” for the PetStore API.
On the API Gateway console, select the PetStore API and choose Actions, Deploy API.
For Stage name, type prod and add a stage description.
Choose Deploy and the new API stage is created.
Use the following AWS CLI command to update your API from edge-optimized to regional:
{
"description": "Your first API with Amazon API Gateway. This is a sample API that integrates via HTTP with your demo Pet Store endpoints",
"createdDate": 1511525626,
"endpointConfiguration": {
"types": [
"REGIONAL"
]
},
"id": "{api-id}",
"name": "PetStore"
}
After you change your API endpoint to regional, you can now assign your own CloudFront distribution to this API.
Create a CloudFront distribution
To make things easier, I have provided an AWS CloudFormation template to deploy a CloudFront distribution pointing to the API that you just created. Click the button to deploy the template in the us-east-1 Region.
For Stack name, enter RegionalAPI. For APIGWEndpoint, enter your API FQDN in the following format:
{api-id}.execute-api.us-east-1.amazonaws.com
After you fill out the parameters, choose Next to continue the stack deployment. It takes a couple of minutes to finish the deployment. After it finishes, the Output tab lists the following items:
A CloudFront domain URL
An S3 bucket for CloudFront access logs
Output from CloudFormation
Test the CloudFront distribution
To see if the CloudFront distribution was configured correctly, use a web browser and enter the URL from your distribution, with the following parameters:
With the new CloudFront distribution in place, you can now start setting up AWS WAF to protect your API.
For this demo, you deploy the AWS WAF Security Automations solution, which provides fine-grained control over the requests attempting to access your API.
For more information about deployment, see Automated Deployment. If you prefer, you can launch the solution directly into your account using the following button.
For CloudFront Access Log Bucket Name, add the name of the bucket created during the deployment of the CloudFormation stack for your CloudFront distribution.
The solution allows you to adjust thresholds and also choose which automations to enable to protect your API. After you finish configuring these settings, choose Next.
To start the deployment process in your account, follow the creation wizard and choose Create. It takes a few minutes do finish the deployment. You can follow the creation process through the CloudFormation console.
After the deployment finishes, you can see the new web ACL deployed on the AWS WAF console, AWSWAFSecurityAutomations.
Attach the AWS WAF web ACL to the CloudFront distribution
With the solution deployed, you can now attach the AWS WAF web ACL to the CloudFront distribution that you created earlier.
To assign the newly created AWS WAF web ACL, go back to your CloudFront distribution. After you open your distribution for editing, choose General, Edit.
Select the new AWS WAF web ACL that you created earlier, AWSWAFSecurityAutomations.
Save the changes to your CloudFront distribution and wait for the deployment to finish.
Test AWS WAF protection
To validate the AWS WAF Web ACL setup, use Artillery to load test your API and see AWS WAF in action.
To install Artillery on your machine, run the following command:
$ npm install -g artillery
After the installation completes, you can check if Artillery installed successfully by running the following command:
$ artillery -V
$ 1.6.0-12
As the time of publication, Artillery is on version 1.6.0-12.
One of the WAF web ACL rules that you have set up is a rate-based rule. By default, it is set up to block any requesters that exceed 2000 requests under 5 minutes. Try this out.
First, use cURL to query your distribution and see the API output:
What you are doing is firing 2000 requests to your API from 10 concurrent users. For brevity, I am not posting the Artillery output here.
After Artillery finishes its execution, try to run the cURL request again and see what happens:
$ curl -s https://{distribution-name}.cloudfront.net/prod/pets
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<HTML><HEAD><META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1">
<TITLE>ERROR: The request could not be satisfied</TITLE>
</HEAD><BODY>
<H1>ERROR</H1>
<H2>The request could not be satisfied.</H2>
<HR noshade size="1px">
Request blocked.
<BR clear="all">
<HR noshade size="1px">
<PRE>
Generated by cloudfront (CloudFront)
Request ID: [removed]
</PRE>
<ADDRESS>
</ADDRESS>
</BODY></HTML>
As you can see from the output above, the request was blocked by AWS WAF. Your IP address is removed from the blocked list after it falls below the request limit rate.
Conclusion
In this first part, you saw how to use the new API Gateway regional API endpoint together with Amazon CloudFront and AWS WAF to secure your API from a series of attacks.
In the second part, I will demonstrate some other techniques to protect your API using API keys and Amazon CloudFront custom headers.
When I talk with customers and partners, I find that they are in different stages in the adoption of DevOps methodologies. They are automating the creation of application artifacts and the deployment of their applications to different infrastructure environments. In many cases, they are creating and supporting multiple applications using a variety of coding languages and artifacts.
The management of these processes and artifacts can be challenging, but using the right tools and methodologies can simplify the process.
In this post, I will show you how you can automate the creation and storage of application artifacts through the implementation of a pipeline and custom deploy action in AWS CodePipeline. The example includes a Node.js code base stored in an AWS CodeCommit repository. A Node Package Manager (npm) artifact is built from the code base, and the build artifact is published to a JFrogArtifactory npm repository.
I frequently recommend AWS CodePipeline, the AWS continuous integration and continuous delivery tool. You can use it to quickly innovate through integration and deployment of new features and bug fixes by building a workflow that automates the build, test, and deployment of new versions of your application. And, because AWS CodePipeline is extensible, it allows you to create a custom action that performs customized, automated actions on your behalf.
JFrog’s Artifactory is a universal binary repository manager where you can manage multiple applications, their dependencies, and versions in one place. Artifactory also enables you to standardize the way you manage your package types across all applications developed in your company, no matter the code base or artifact type.
If you already have a Node.js CodeCommit repository, a JFrog Artifactory host, and would like to automate the creation of the pipeline, including the custom action and CodeBuild project, you can use this AWS CloudFormationtemplate to create your AWS CloudFormation stack.
This figure shows the path defined in the pipeline for this project. It starts with a change to Node.js source code committed to a private code repository in AWS CodeCommit. With this change, CodePipeline triggers AWS CodeBuild to create the npm package from the node.js source code. After the build, CodePipeline triggers the custom action job worker to commit the build artifact to the designated artifact repository in Artifactory.
This blog post assumes you have already:
· Created a CodeCommit repository that contains a Node.js project.
· Configured a two-stage pipeline in AWS CodePipeline.
The Source stage of the pipeline is configured to poll the Node.js CodeCommit repository. The Build stage is configured to use a CodeBuild project to build the npm package using a buildspec.yml file located in the code repository.
If you do not have a Node.js repository, you can create a CodeCommit repository that contains this simple ‘Hello World’ project. This project also includes a buildspec.yml file that is used when you define your CodeBuild project. It defines the steps to be taken by CodeBuild to create the npm artifact.
If you do not already have a pipeline set up in CodePipeline, you can use this template to create a pipeline with a CodeCommit source action and a CodeBuild build action through the AWS Command Line Interface (AWS CLI). If you do not want to install the AWS CLI on your local machine, you can use AWS Cloud9, our managed integrated development environment (IDE), to interact with AWS APIs.
In your development environment, open your favorite editor and fill out the template with values appropriate to your project. For information, see the readme in the GitHub repository.
Use this CLI command to create the pipeline from the template:
aws codepipeline create-pipeline – cli-input-json file://source-build-actions-codepipeline.json – region 'us-west-2'
It creates a pipeline that has a CodeCommit source action and a CodeBuild build action.
Integrating JFrog Artifactory
JFrog Artifactory provides default repositories for your project needs. For my NPM package repository, I am using the default virtual npm repository (named npm) that is available in Artifactory Pro. You might want to consider creating a repository per project but for the example used in this post, using the default lets me get started without having to configure a new repository.
I can use the steps in the Set Me Up -> npm section on the landing page to configure my worker to interact with the default NPM repository.
Describes the required values to run the custom action. I will define my custom action in the ‘Deploy’ category, identify the provider as ‘Artifactory’, of version ‘1’, and specify a variety of configurationProperties whose values will be defined when this stage is added to my pipeline.
Polls CodePipeline for a job, scanning for its action-definition properties. In this blog post, after a job has been found, the job worker does the work required to publish the npm artifact to the Artifactory repository.
{
"category": "Deploy",
"configurationProperties": [{
"name": "TypeOfArtifact",
"required": true,
"key": true,
"secret": false,
"description": "Package type, ex. npm for node packages",
"type": "String"
},
{ "name": "RepoKey",
"required": true,
"key": true,
"secret": false,
"type": "String",
"description": "Name of the repository in which this artifact should be stored"
},
{ "name": "UserName",
"required": true,
"key": true,
"secret": false,
"type": "String",
"description": "Username for authenticating with the repository"
},
{ "name": "Password",
"required": true,
"key": true,
"secret": true,
"type": "String",
"description": "Password for authenticating with the repository"
},
{ "name": "EmailAddress",
"required": true,
"key": true,
"secret": false,
"type": "String",
"description": "Email address used to authenticate with the repository"
},
{ "name": "ArtifactoryHost",
"required": true,
"key": true,
"secret": false,
"type": "String",
"description": "Public address of Artifactory host, ex: https://myexamplehost.com or http://myexamplehost.com:8080"
}],
"provider": "Artifactory",
"version": "1",
"settings": {
"entityUrlTemplate": "{Config:ArtifactoryHost}/artifactory/webapp/#/artifacts/browse/tree/General/{Config:RepoKey}"
},
"inputArtifactDetails": {
"maximumCount": 5,
"minimumCount": 1
},
"outputArtifactDetails": {
"maximumCount": 5,
"minimumCount": 0
}
}
There are seven sections to the custom action definition:
category: This is the stage in which you will be creating this action. It can be Source, Build, Deploy, Test, Invoke, Approval. Except for source actions, the category section simply allows us to organize our actions. I am setting the category for my action as ‘Deploy’ because I’m using it to publish my node artifact to my Artifactory instance.
configurationProperties: These are the parameters or variables required for your project to authenticate and commit your artifact. In the case of my custom worker, I need:
TypeOfArtifact: In this case, npm, because it’s for the Node Package Manager.
RepoKey: The name of the repository. In this case, it’s the default npm.
UserName and Password for the user to authenticate with the Artifactory repository.
EmailAddress used to authenticate with the repository.
Artifactory host name or IP address.
provider: The name you define for your custom action stage. I have named the provider Artifactory.
version: Version number for the custom action. Because this is the first version, I set the version number to 1.
entityUrlTemplate: This URL is presented to your users for the deploy stage along with the title you define in your provider. The link takes the user to their artifact repository page in the Artifactory host.
inputArtifactDetails: The number of artifacts to expect from the previous stage in the pipeline.
outputArtifactDetails: The number of artifacts that should be the result from the custom action stage. Later in this blog post, I define 0 for my output artifacts because I am publishing the artifact to the Artifactory repository as the final action.
After I define the custom action in a JSON file, I use the AWS CLI to create the custom action type in CodePipeline:
After I create the custom action type in the same region as my pipeline, I edit the pipeline to add a Deploy stage and configure it to use the custom action I created for Artifactory:
I have created a custom worker for the actions required to commit the npm artifact to the Artifactory repository. The worker is in Python and it runs in a loop on an Amazon EC2 instance. My custom worker polls for a deploy job and publishes the NPM artifact to the Artifactory repository.
The EC2 instance is running Amazon Linux and has an IAM instance role attached that gives the worker permission to access CodePipeline. The worker process is as follows:
Take the configuration properties from the custom worker and poll CodePipeline for a custom action job.
After there is a job in the job queue with the appropriate category, provider, and version, acknowledge the job.
Download the zipped artifact created in the previous Build stage from the provided S3 buckets with the provided temporary credentials.
Unzip the artifact into a temporary directory.
A user-defined Artifactory user name and password is used to receive a temporary API key from Artifactory.
To avoid having to write the password to a file, use that temporary API key and user name to authenticate with the NPM repository.
Publish the Node.js package to the specified repository.
Because I am running my custom worker on an Amazon Linux EC2 instance, I installed npm with the following command:
sudo yum install nodejs npm – enablerepo=epel
For my custom worker, I used pip to install the required Python libraries:
pip install boto3 requests
For a full Python package list, see requirements.txt in the GitHub repository.
Let’s take a look at some of the code snippets from the worker.
First, the worker polls for jobs:
def action_type():
ActionType = {
'category': 'Deploy',
'owner': 'Custom',
'provider': 'Artifactory',
'version': '1' }
return(ActionType)
def poll_for_jobs():
try:
artifactory_action_type = action_type()
print(artifactory_action_type)
jobs = codepipeline.poll_for_jobs(actionTypeId=artifactory_action_type)
while not jobs['jobs']:
time.sleep(10)
jobs = codepipeline.poll_for_jobs(actionTypeId=artifactory_action_type)
if jobs['jobs']:
print('Job found')
return jobs['jobs'][0]
except ClientError as e:
print("Received an error: %s" % str(e))
raise
When there is a job in the queue, the poller returns a number of values from the queue such as jobId, the input and output S3 buckets for artifacts, temporary credentials to access the S3 buckets, and other configuration details from the stage in the pipeline.
After successfully receiving the job details, the worker sends an acknowledgement to CodePipeline to ensure that the work on the job is not duplicated by other workers watching for the same job:
def job_acknowledge(jobId, nonce):
try:
print('Acknowledging job')
result = codepipeline.acknowledge_job(jobId=jobId, nonce=nonce)
return result
except Exception as e:
print("Received an error when trying to acknowledge the job: %s" % str(e))
raise
With the job now acknowledged, the worker publishes the source code artifact into the desired repository. The worker gets the value of the artifact S3 bucket and objectKey from the inputArtifacts in the response from the poll_for_jobs API request. Next, the worker creates a new directory in /tmp and downloads the S3 object into this directory:
def get_bucket_location(bucketName, init_client):
region = init_client.get_bucket_location(Bucket=bucketName)['LocationConstraint']
if not region:
region = 'us-east-1'
return region
def get_s3_artifact(bucketName, objectKey, ak, sk, st):
init_s3 = boto3.client('s3')
region = get_bucket_location(bucketName, init_s3)
session = Session(aws_access_key_id=ak,
aws_secret_access_key=sk,
aws_session_token=st)
s3 = session.resource('s3',
region_name=region,
config=botocore.client.Config(signature_version='s3v4'))
try:
tempdirname = tempfile.mkdtemp()
except OSError as e:
print('Could not write temp directory %s' % tempdirname)
raise
bucket = s3.Bucket(bucketName)
obj = bucket.Object(objectKey)
filename = tempdirname + '/' + objectKey
try:
if os.path.dirname(objectKey):
directory = os.path.dirname(filename)
os.makedirs(directory)
print('Downloading the %s object and writing it to disk in %s location' % (objectKey, tempdirname))
with open(filename, 'wb') as data:
obj.download_fileobj(data)
except ClientError as e:
print('Downloading the object and writing the file to disk raised this error: ' + str(e))
raise
return(filename, tempdirname)
Because the downloaded artifact from S3 is a zip file, the worker must unzip it first. To have a clean area in which to work, I extract the downloaded zip archive into a new directory:
def unzip_codepipeline_artifact(artifact, origtmpdir):
# create a new temp directory
# Unzip artifact into new directory
try:
newtempdir = tempfile.mkdtemp()
print('Extracting artifact %s into temporary directory %s' % (artifact, newtempdir))
zip_ref = zipfile.ZipFile(artifact, 'r')
zip_ref.extractall(newtempdir)
zip_ref.close()
shutil.rmtree(origtmpdir)
return(os.listdir(newtempdir), newtempdir)
except OSError as e:
if e.errno != errno.EEXIST:
shutil.rmtree(newtempdir)
raise
The worker now has the npm package that I want to store in my Artifactory NPM repository.
To authenticate with the NPM repository, the worker requests a temporary token from the Artifactory host. After receiving this temporary token, it creates a .npmrc file in the worker user’s home directory that includes a hash of the user name and temporary token. After it has authenticated, the worker runs npm config set registry <URL OF REPOSITORY> to configure the npm registry value to be the Artifactory host. Next, the worker runs npm publish –registry <URL OF REPOSITORY>, which publishes the node package to the NPM repository in the Artifactory host.
def push_to_npm(configuration, artifact_list, temp_dir, jobId):
reponame = configuration['RepoKey']
art_type = configuration['TypeOfArtifact']
print("Putting artifact into NPM repository " + reponame)
token, hostname, username = gen_artifactory_auth_token(configuration)
npmconfigfile = create_npmconfig_file(configuration, username, token)
url = hostname + '/artifactory/api/' + art_type + '/' + reponame
print("Changing directory to " + str(temp_dir))
os.chdir(temp_dir)
try:
print("Publishing following files to the repository: %s " % os.listdir(temp_dir))
print("Sending artifact to Artifactory NPM registry URL: " + url)
subprocess.call(["npm", "config", "set", "registry", url])
req = subprocess.call(["npm", "publish", "--registry", url])
print("Return code from npm publish: " + str(req))
if req != 0:
err_msg = "npm ERR! Recieved non OK response while sending response to Artifactory. Return code from npm publish: " + str(req)
signal_failure(jobId, err_msg)
else:
signal_success(jobId)
except requests.exceptions.RequestException as e:
print("Received an error when trying to commit artifact %s to repository %s: " % (str(art_type), str(configuration['RepoKey']), str(e)))
raise
return(req, npmconfigfile)
If the return value from publishing to the repository is not 0, the worker signals a failure to CodePipeline. If the value is 0, the worker signals success to CodePipeline to indicate that the stage of the pipeline has been completed successfully.
For the custom worker code, see npm_job_worker.py in the GitHub repository.
I run my custom worker on an EC2 instance using the command python npm_job_worker.py, with an optional --version flag that can be used to specify worker versions other than 1. Then I trigger a release change in my pipeline:
From my custom worker output logs, I have just committed a package named node_example at version 1.0.3:
On artifact: index.js
Committing to the repo: https://artifactory.myexamplehost.com/artifactory/api/npm/npm
Sending artifact to Artifactory URL: https:// artifactoryhost.myexamplehost.com/artifactory/api/npm/npm
npm config: 0
npm http PUT https://artifactory.myexamplehost.com/artifactory/api/npm/npm/node_example
npm http 201 https://artifactory.myexamplehost.com/artifactory/api/npm/npm/node_example
+ [email protected]
Return code from npm publish: 0
Signaling success to CodePipeline
After that has been built successfully, I can find my artifact in my Artifactory repository:
To help you automate this process, I have created this AWS CloudFormation template that automates the creation of the CodeBuild project, the custom action, and the CodePipeline pipeline. It also launches the Amazon EC2-based custom job worker in an AWS Auto Scaling group. This template requires you to have a VPC and CodeCommit repository for your Node.js project. If you do not currently have a VPC in which you want to run your custom worker EC2 instances, you can use this AWS QuickStart to create one. If you do not have an existing Node.js project, I’ve provided a sample project in the GitHub repository.
Conclusion
I‘ve shown you the steps to integrate your JFrog Artifactory repository with your CodePipeline workflow. I’ve shown you how to create a custom action in CodePipeline and how to create a custom worker that works in your CI/CD pipeline. To dig deeper into custom actions and see how you can integrate your Artifactory repositories into your AWS CodePipeline projects, check out the full code base on GitHub.
If you have any questions or feedback, feel free to reach out to us through the AWS CodePipeline forum.
Erin McGill is a Solutions Architect in the AWS Partner Program with a focus on DevOps and automation tooling.
Slack is widely used by DevOps and development teams to communicate status. Typically, when a build has been tested and is ready to be promoted to a staging environment, a QA engineer or DevOps engineer kicks off the deployment. Using Slack in a ChatOps collaboration model, the promotion can be done in a single click from a Slack channel. And because the promotion happens through a Slack channel, the whole development team knows what’s happening without checking email.
In this blog post, I will show you how to integrate AWS services with a Slack application. I use an interactive message button and incoming webhook to promote a stage with a single click.
To follow along with the steps in this post, you’ll need a pipeline in AWS CodePipeline. If you don’t have a pipeline, the fastest way to create one for this use case is to use AWS CodeStar. Go to the AWS CodeStar console and select the Static Website template (shown in the screenshot). AWS CodeStar will create a pipeline with an AWS CodeCommit repository and an AWS CodeDeploy deployment for you. After the pipeline is created, you will need to add a manual approval stage.
You’ll also need to build a Slack app with webhooks and interactive components, write two Lambda functions, and create an API Gateway API and a SNS topic.
As you’ll see in the following diagram, when I make a change and merge a new feature into the master branch in AWS CodeCommit, the check-in kicks off my CI/CD pipeline in AWS CodePipeline. When CodePipeline reaches the approval stage, it sends a notification to Amazon SNS, which triggers an AWS Lambda function (ApprovalRequester).
The Slack channel receives a prompt that looks like the following screenshot. When I click Yes to approve the build promotion, the approval result is sent to CodePipeline through API Gateway and Lambda (ApprovalHandler). The pipeline continues on to deploy the build to the next environment.
Create a Slack app
For App Name, type a name for your app. For Development Slack Workspace, choose the name of your workspace. You’ll see in the following screenshot that my workspace is AWS ChatOps.
After the Slack application has been created, you will see the Basic Information page, where you can create incoming webhooks and enable interactive components.
To add incoming webhooks:
Under Add features and functionality, choose Incoming Webhooks. Turn the feature on by selecting Off, as shown in the following screenshot.
Now that the feature is turned on, choose Add New Webhook to Workspace. In the process of creating the webhook, Slack lets you choose the channel where messages will be posted.
After the webhook has been created, you’ll see its URL. You will use this URL when you create the Lambda function.
If you followed the steps in the post, the pipeline should look like the following.
Write the Lambda function for approval requests
This Lambda function is invoked by the SNS notification. It sends a request that consists of an interactive message button to the incoming webhook you created earlier. The following sample code sends the request to the incoming webhook. WEBHOOK_URL and SLACK_CHANNEL are the environment variables that hold values of the webhook URL that you created and the Slack channel where you want the interactive message button to appear.
# This function is invoked via SNS when the CodePipeline manual approval action starts.
# It will take the details from this approval notification and sent an interactive message to Slack that allows users to approve or cancel the deployment.
import os
import json
import logging
import urllib.parse
from base64 import b64decode
from urllib.request import Request, urlopen
from urllib.error import URLError, HTTPError
# This is passed as a plain-text environment variable for ease of demonstration.
# Consider encrypting the value with KMS or use an encrypted parameter in Parameter Store for production deployments.
SLACK_WEBHOOK_URL = os.environ['SLACK_WEBHOOK_URL']
SLACK_CHANNEL = os.environ['SLACK_CHANNEL']
logger = logging.getLogger()
logger.setLevel(logging.INFO)
def lambda_handler(event, context):
print("Received event: " + json.dumps(event, indent=2))
message = event["Records"][0]["Sns"]["Message"]
data = json.loads(message)
token = data["approval"]["token"]
codepipeline_name = data["approval"]["pipelineName"]
slack_message = {
"channel": SLACK_CHANNEL,
"text": "Would you like to promote the build to production?",
"attachments": [
{
"text": "Yes to deploy your build to production",
"fallback": "You are unable to promote a build",
"callback_id": "wopr_game",
"color": "#3AA3E3",
"attachment_type": "default",
"actions": [
{
"name": "deployment",
"text": "Yes",
"style": "danger",
"type": "button",
"value": json.dumps({"approve": True, "codePipelineToken": token, "codePipelineName": codepipeline_name}),
"confirm": {
"title": "Are you sure?",
"text": "This will deploy the build to production",
"ok_text": "Yes",
"dismiss_text": "No"
}
},
{
"name": "deployment",
"text": "No",
"type": "button",
"value": json.dumps({"approve": False, "codePipelineToken": token, "codePipelineName": codepipeline_name})
}
]
}
]
}
req = Request(SLACK_WEBHOOK_URL, json.dumps(slack_message).encode('utf-8'))
response = urlopen(req)
response.read()
return None
Create a SNS topic
Create a topic and then create a subscription that invokes the ApprovalRequester Lambda function. You can configure the manual approval action in the pipeline to send a message to this SNS topic when an approval action is required. When the pipeline reaches the approval stage, it sends a notification to this SNS topic. SNS publishes a notification to all of the subscribed endpoints. In this case, the Lambda function is the endpoint. Therefore, it invokes and executes the Lambda function. For information about how to create a SNS topic, see Create a Topic in the Amazon SNS Developer Guide.
Write the Lambda function for handling the interactive message button
This Lambda function is invoked by API Gateway. It receives the result of the interactive message button whether or not the build promotion was approved. If approved, an API call is made to CodePipeline to promote the build to the next environment. If not approved, the pipeline stops and does not move to the next stage.
The Lambda function code might look like the following. SLACK_VERIFICATION_TOKEN is the environment variable that contains your Slack verification token. You can find your verification token under Basic Information on Slack manage app page. When you scroll down, you will see App Credential. Verification token is found under the section.
# This function is triggered via API Gateway when a user acts on the Slack interactive message sent by approval_requester.py.
from urllib.parse import parse_qs
import json
import os
import boto3
SLACK_VERIFICATION_TOKEN = os.environ['SLACK_VERIFICATION_TOKEN']
#Triggered by API Gateway
#It kicks off a particular CodePipeline project
def lambda_handler(event, context):
#print("Received event: " + json.dumps(event, indent=2))
body = parse_qs(event['body'])
payload = json.loads(body['payload'][0])
# Validate Slack token
if SLACK_VERIFICATION_TOKEN == payload['token']:
send_slack_message(json.loads(payload['actions'][0]['value']))
# This will replace the interactive message with a simple text response.
# You can implement a more complex message update if you would like.
return {
"isBase64Encoded": "false",
"statusCode": 200,
"body": "{\"text\": \"The approval has been processed\"}"
}
else:
return {
"isBase64Encoded": "false",
"statusCode": 403,
"body": "{\"error\": \"This request does not include a vailid verification token.\"}"
}
def send_slack_message(action_details):
codepipeline_status = "Approved" if action_details["approve"] else "Rejected"
codepipeline_name = action_details["codePipelineName"]
token = action_details["codePipelineToken"]
client = boto3.client('codepipeline')
response_approval = client.put_approval_result(
pipelineName=codepipeline_name,
stageName='Approval',
actionName='ApprovalOrDeny',
result={'summary':'','status':codepipeline_status},
token=token)
print(response_approval)
Create the API Gateway API
In the Amazon API Gateway console, create a resource called InteractiveMessageHandler.
Create a POST method.
For Integration type, choose Lambda Function.
Select Use Lambda Proxy integration.
From Lambda Region, choose a region.
In Lambda Function, type a name for your function.
Now go back to your Slack application and enable interactive components.
To enable interactive components for the interactive message (Yes) button:
Under Features, choose Interactive Components.
Choose Enable Interactive Components.
Type a request URL in the text box. Use the invoke URL in Amazon API Gateway that will be called when the approval button is clicked.
Now that all the pieces have been created, run the solution by checking in a code change to your CodeCommit repo. That will release the change through CodePipeline. When the CodePipeline comes to the approval stage, it will prompt to your Slack channel to see if you want to promote the build to your staging or production environment. Choose Yes and then see if your change was deployed to the environment.
Conclusion
That is it! You have now created a Slack ChatOps solution using AWS CodeCommit, AWS CodePipeline, AWS Lambda, Amazon API Gateway, and Amazon Simple Notification Service.
Now that you know how to do this Slack and CodePipeline integration, you can use the same method to interact with other AWS services using API Gateway and Lambda. You can also use Slack’s slash command to initiate an action from a Slack channel, rather than responding in the way demonstrated in this post.
We’re usually averse to buzzwords at HackSpace magazine, but not this month: in issue 7, we’re taking a deep dive into the Internet of Things.
Internet of Things (IoT)
To many people, IoT is a shady term used by companies to sell you something you already own, but this time with WiFi; to us, it’s a way to make our builds smarter, more useful, and more connected. In HackSpace magazine #7, you can join us on a tour of the boards that power IoT projects, marvel at the ways in which other makers are using IoT, and get started with your first IoT project!
Awesome projects
DIY retro computing: this issue, we’re taking our collective hat off to Spencer Owen. He stuck his home-brew computer on Tindie thinking he might make a bit of beer money — now he’s paying the mortgage with his making skills and inviting others to build modules for his machine. And if that tickles your fancy, why not take a crack at our Z80 tutorial? Get out your breadboard, assemble your jumper wires, and prepare to build a real-life computer!
Shameless patriotism: combine Lego, Arduino, and the car of choice for 1960 gold bullion thieves, and you’ve got yourself a groovy weekend project. We proudly present to you one man’s epic quest to add LED lights (controllable via a smartphone!) to his daughter’s LEGO Mini Cooper.
Makerspaces
Patriotism intensifies: for the last 200-odd years, the Black Country has been a hotbed of making. Urban Hax, based in Walsall, is the latest makerspace to show off its riches in the coveted Space of the Month pages. Every space has its own way of doing things, but not every space has a portrait of Rob Halford on the wall. All hail!
Diversity: advice on diversity often boils down to ‘Be nice to people’, which might feel more vague than actionable. This is where we come in to help: it is truly worth making the effort to give people of all backgrounds access to your makerspace, so we take a look at why it’s nice to be nice, and at the ways in which one makerspace has put niceness into practice — with great results.
And there’s more!
We also show you how to easily calculate the size and radius of laser-cut gears, use a bank of LEDs to etch PCBs in your own mini factory, and use chemistry to mess with your lunch menu.
All this plus much, much more waits for you in HackSpace magazine issue 7!
Get your copy of HackSpace magazine
If you like the sound of that, you can find HackSpace magazine in WHSmith, Tesco, Sainsbury’s, and independent newsagents in the UK. If you live in the US, check out your local Barnes & Noble, Fry’s, or Micro Center next week. We’re also shipping to stores in Australia, Hong Kong, Canada, Singapore, Belgium, and Brazil, so be sure to ask your local newsagent whether they’ll be getting HackSpace magazine.
I’m in danger of contradicting myself, after previously pointing out that x86 machine code is a high-level language, but this article claiming C is a not a low level language is bunk. C certainly has some problems, but it’s still the closest language to assembly. This is obvious by the fact it’s still the fastest compiled language. What we see is a typical academic out of touch with the real world.
The author makes the (wrong) observation that we’ve been stuck emulating the PDP-11 for the past 40 years. C was written for the PDP-11, and since then CPUs have been designed to make C run faster. The author imagines a different world, such as where CPU designers instead target something like LISP as their preferred language, or Erlang. This misunderstands the state of the market. CPUs do indeed supports lots of different abstractions, and C has evolved to accommodate this.
The author criticizes things like “out-of-order” execution which has lead to the Spectre sidechannel vulnerabilities. Out-of-order execution is necessary to make C run faster. The author claims instead that those resources should be spent on having more slower CPUs, with more threads. This sacrifices single-threaded performance in exchange for a lot more threads executing in parallel. The author cites Sparc Tx CPUs as his ideal processor.
But here’s the thing, the Sparc Tx was a failure. To be fair, it’s mostly a failure because most of the time, people wanted to run old C code instead of new Erlang code. But it was still a failure at running Erlang.
Time after time, engineers keep finding that “out-of-order”, single-threaded performance is still the winner. A good example is ARM processors for both mobile phones and servers. All the theory points to in-order CPUs as being better, but all the products are out-of-order, because this theory is wrong. The custom ARM cores from Apple and Qualcomm used in most high-end phones are so deeply out-of-order they give Intel CPUs competition. The same is true on the server front with the latest Qualcomm Centriq and Cavium ThunderX2 processors, deeply out of order supporting more than 100 instructions in flight.
The Cavium is especially telling. Its ThunderX CPU had 48 simple cores which was replaced with the ThunderX2 having 32 complex, deeply out-of-order cores. The performance increase was massive, even on multithread-friendly workloads. Every competitor to Intel’s dominance in the server space has learned the lesson from Sparc Tx: many wimpy cores is a failure, you need fewer beefy cores. Yes, they don’t need to be as beefy as Intel’s processors, but they need to be close.
Even Intel’s “Xeon Phi” custom chip learned this lesson. This is their GPU-like chip, running 60 cores with 512-bit wide “vector” (sic) instructions, designed for supercomputer applications. Its first version was purely in-order. Its current version is slightly out-of-order. It supports four threads and focuses on basic number crunching, so in-order cores seems to be the right approach, but Intel found in this case that out-of-order processing still provided a benefit. Practice is different than theory.
As an academic, the author of the above article focuses on abstractions. The criticism of C is that it has the wrong abstractions which are hard to optimize, and that if we instead expressed things in the right abstractions, it would be easier to optimize.
This is an intellectually compelling argument, but so far bunk.
The reason is that while the theoretical base language has issues, everyone programs using extensions to the language, like “intrinsics” (C ‘functions’ that map to assembly instructions). Programmers write libraries using these intrinsics, which then the rest of the normal programmers use. In other words, if your criticism is that C is not itself low level enough, it still provides the best access to low level capabilities.
Given that C can access new functionality in CPUs, CPU designers add new paradigms, from SIMD to transaction processing. In other words, while in the 1980s CPUs were designed to optimize C (stacks, scaled pointers), these days CPUs are designed to optimize tasks regardless of language.
The author of that article criticizes the memory/cache hierarchy, claiming it has problems. Yes, it has problems, but only compared to how well it normally works. The author praises the many simple cores/threads idea as hiding memory latency with little caching, but misses the point that caches also dramatically increase memory bandwidth. Intel processors are optimized to read a whopping 256 bits every clock cycle from L1 cache. Main memory bandwidth is orders of magnitude slower.
The author goes onto criticize cache coherency as a problem. C uses it, but other languages like Erlang don’t need it. But that’s largely due to the problems each languages solves. Erlang solves the problem where a large number of threads work on largely independent tasks, needing to send only small messages to each other across threads. The problems C solves is when you need many threads working on a huge, common set of data.
For example, consider the “intrusion prevention system”. Any thread can process any incoming packet that corresponds to any region of memory. There’s no practical way of solving this problem without a huge coherent cache. It doesn’t matter which language or abstractions you use, it’s the fundamental constraint of the problem being solved. RDMA is an important concept that’s moved from supercomputer applications to the data center, such as with memcached. Again, we have the problem of huge quantities (terabytes worth) shared among threads rather than small quantities (kilobytes).
The fundamental issue the author of the the paper is ignoring is decreasing marginal returns. Moore’s Law has gifted us more transistors than we can usefully use. We can’t apply those additional registers to just one thing, because the useful returns we get diminish.
For example, Intel CPUs have two hardware threads per core. That’s because there are good returns by adding a single additional thread. However, the usefulness of adding a third or fourth thread decreases. That’s why many CPUs have only two threads, or sometimes four threads, but no CPU has 16 threads per core.
You can apply the same discussion to any aspect of the CPU, from register count, to SIMD width, to cache size, to out-of-order depth, and so on. Rather than focusing on one of these things and increasing it to the extreme, CPU designers make each a bit larger every process tick that adds more transistors to the chip.
The same applies to cores. It’s why the “more simpler cores” strategy fails, because more cores have their own decreasing marginal returns. Instead of adding cores tied to limited memory bandwidth, it’s better to add more cache. Such cache already increases the size of the cores, so at some point it’s more effective to add a few out-of-order features to each core rather than more cores. And so on.
The question isn’t whether we can change this paradigm and radically redesign CPUs to match some academic’s view of the perfect abstraction. Instead, the goal is to find new uses for those additional transistors. For example, “message passing” is a useful abstraction in languages like Go and Erlang that’s often more useful than sharing memory. It’s implemented with shared memory and atomic instructions, but I can’t help but think it couldn’t better be done with direct hardware support.
Of course, as soon as they do that, it’ll become an intrinsic in C, then added to languages like Go and Erlang.
Summary Academics live in an ideal world of abstractions, the rest of us live in practical reality. The reality is that vast majority of programmers work with the C family of languages (JavaScript, Go, etc.), whereas academics love the epiphanies they learned using other languages, especially function languages. CPUs are only superficially designed to run C and “PDP-11 compatibility”. Instead, they keep adding features to support other abstractions, abstractions available to C. They are driven by decreasing marginal returns — they would love to add new abstractions to the hardware because it’s a cheap way to make use of additional transitions. Academics are wrong believing that the entire system needs to be redesigned from scratch. Instead, they just need to come up with new abstractions CPU designers can add.
Side projects are the things you do at home, after work, for your own “entertainment”, or to satisfy your desire to learn new stuff, in case your workplace doesn’t give you that opportunity (or at least not enough of it). Side projects are also a way to build stuff that you think is valuable but not necessarily “commercialisable”. Many side projects are open-sourced sooner or later and some of them contribute to the pool of tools at other people’s disposal.
I’ve outlined one recommendation about side projects before – do them with technologies that are new to you, so that you learn important things that will keep you better positioned in the software world.
But there are more benefits than that – serendipitous benefits, for example. And I’d like to tell some personal stories about that. I’ll focus on a few examples from my list of side projects to show how, through a sort-of butterfly effect, they helped shape my career.
The computoser project, no matter how cool algorithmic music composition, didn’t manage to have much of a long term impact. But it did teach me something apart from niche musical theory – how to read a bulk of scientific papers (mostly computer science) and understand them without being formally trained in the particular field. We’ll see how that was useful later.
Then there was the “State alerts” project – a website that scraped content from public institutions in my country (legislation, legislation proposals, decisions by regulators, new tenders, etc.), made them searchable, and “subscribable” – so that you get notified when a keyword of interest is mentioned in newly proposed legislation, for example. (I obviously subscribed for “information technologies” and “electronic”).
And that project turned out to have a significant impact on the following years. First, I chose a new technology to write it with – Scala. Which turned out to be of great use when I started working at TomTom, and on the 3rd day I was transferred to a Scala project, which was way cooler and much more complex than the original one I was hired for. It was a bit ironic, as my colleagues had just read that “I don’t like Scala” a few weeks earlier, but nevertheless, that was one of the most interesting projects I’ve worked on, and it went on for two years. Had I not known Scala, I’d probably be gone from TomTom much earlier (as the other project was restructured a few times), and I would not have learned many of the scalability, architecture and AWS lessons that I did learn there.
But the very same project had an even more important follow-up. Because if its “civic hacking” flavour, I was invited to join an informal group of developers (later officiated as an NGO) who create tools that are useful for society (something like MySociety.org). That group gathered regularly, discussed both tools and policies, and at some point we put up a list of policy priorities that we wanted to lobby policy makers. One of them was open source for the government, the other one was open data. As a result of our interaction with an interim government, we donated the official open data portal of my country, functioning to this day.
As a result of that, a few months later we got a proposal from the deputy prime minister’s office to “elect” one of the group for an advisor to the cabinet. And we decided that could be me. So I went for it and became advisor to the deputy prime minister. The job has nothing to do with anything one could imagine, and it was challenging and fascinating. We managed to pass legislation, including one that requires open source for custom projects, eID and open data. And all of that would not have been possible without my little side project.
As for my latest side project, LogSentinel – it became my current startup company. And not without help from the previous two mentioned above – the computer science paper reading was of great use when I was navigating the crypto papers landscape, and from the government job I not only gained invaluable legal knowledge, but I also “got” a co-founder.
Some other side projects died without much fanfare, and that’s fine. But the ones above shaped my “story” in a way that would not have been possible otherwise.
And I agree that such serendipitous chain of events could have happened without side projects – I could’ve gotten these opportunities by meeting someone at a bar (unlikely, but who knows). But we, as software engineers, are capable of tilting chance towards us by utilizing our skills. Side projects are our “extracurricular activities”, and they often lead to unpredictable, but rather positive chains of events. They would rarely be the only factor, but they are certainly great at unlocking potential.
Today we’re launching a new partnership between the Scouts and the Raspberry Pi Foundation that will help tens of thousands of young people learn crucial digital skills for life. In this blog post, I want to explain what we’ve got planned, why it matters, and how you can get involved.
This is personal
First, let me tell you why this partnership matters to me. As a child growing up in North Wales in the 1980s, Scouting changed my life. My time with 2nd Rhyl provided me with countless opportunities to grow and develop new skills. It taught me about teamwork and community in ways that continue to shape my decisions today.
As my own kids (now seven and ten) have joined Scouting, I’ve seen the same opportunities opening up for them, and like so many parents, I’ve come back to the movement as a volunteer to support their local section. So this is deeply personal for me, and the same is true for many of my colleagues at the Raspberry Pi Foundation who in different ways have been part of the Scouting movement.
That shouldn’t come as a surprise. Scouting and Raspberry Pi share many of the same values. We are both community-led movements that aim to help young people develop the skills they need for life. We are both powered by an amazing army of volunteers who give their time to support that mission. We both care about inclusiveness, and pride ourselves on combining fun with learning by doing.
Raspberry Pi
Raspberry Pi started life in 2008 as a response to the problem that too many young people were growing up without the skills to create with technology. Our goal is that everyone should be able to harness the power of computing and digital technologies, for work, to solve problems that matter to them, and to express themselves creatively.
In 2012 we launched our first product, the world’s first $35 computer. Just six years on, we have sold over 20 million Raspberry Pi computers and helped kickstart a global movement for digital skills.
The Raspberry Pi Foundation now runs the world’s largest network of volunteer-led computing clubs (Code Clubs and CoderDojos), and creates free educational resources that are used by millions of young people all over the world to learn how to create with digital technologies. And lots of what we are able to achieve is because of partnerships with fantastic organisations that share our goals. For example, through our partnership with the European Space Agency, thousands of young people have written code that has run on two Raspberry Pi computers that Tim Peake took to the International Space Station as part of his Mission Principia.
Digital makers
Today we’re launching the new Digital Maker Staged Activity Badge to help tens of thousands of young people learn how to create with technology through Scouting. Over the past few months, we’ve been working with the Scouts all over the UK to develop and test the new badge requirements, along with guidance, project ideas, and resources that really make them work for Scouting. We know that we need to get two things right: relevance and accessibility.
Relevance is all about making sure that the activities and resources we provide are a really good fit for Scouting and Scouting’s mission to equip young people with skills for life. From the digital compass to nature cameras and the reinvented wide game, we’ve had a lot of fun thinking about ways we can bring to life the crucial role that digital technologies can play in the outdoors and adventure.
We are beyond excited to be launching a new partnership with the Raspberry Pi Foundation, which will help tens of thousands of young people learn digital skills for life.
We also know that there are great opportunities for Scouts to use digital technologies to solve social problems in their communities, reflecting the movement’s commitment to social action. Today we’re launching the first set of project ideas and resources, with many more to follow over the coming weeks and months.
Accessibility is about providing every Scout leader with the confidence, support, and kit to enable them to offer the Digital Maker Staged Activity Badge to their young people. A lot of work and care has gone into designing activities that require very little equipment: for example, activities at Stages 1 and 2 can be completed with a laptop without access to the internet. For the activities that do require kit, we will be working with Scout Stores and districts to make low-cost kit available to buy or loan.
We’re producing accessible instructions, worksheets, and videos to help leaders run sessions with confidence, and we’ll also be planning training for leaders. We will work with our network of Code Clubs and CoderDojos to connect them with local sections to organise joint activities, bringing both kit and expertise along with them.
Get involved
Today’s launch is just the start. We’ll be developing our partnership over the next few years, and we can’t wait for you to join us in getting more young people making things with technology.
Take a look at the brand-new Raspberry Pi resources designed especially for Scouts, to get young people making and creating right away.
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