All posts by Tiffany Jernigan

Migrating Your Amazon ECS Containers to AWS Fargate

Post Syndicated from Tiffany Jernigan original https://aws.amazon.com/blogs/compute/migrating-your-amazon-ecs-containers-to-aws-fargate/

AWS Fargate is a new technology that works with Amazon Elastic Container Service (ECS) to run containers without having to manage servers or clusters. What does this mean? With Fargate, you no longer need to provision or manage a single virtual machine; you can just create tasks and run them directly!

Fargate uses the same API actions as ECS, so you can use the ECS console, the AWS CLI, or the ECS CLI. I recommend running through the first-run experience for Fargate even if you’re familiar with ECS. It creates all of the one-time setup requirements, such as the necessary IAM roles. If you’re using a CLI, make sure to upgrade to the latest version

In this blog, you will see how to migrate ECS containers from running on Amazon EC2 to Fargate.

Getting started

Note: Anything with code blocks is a change in the task definition file. Screen captures are from the console. Additionally, Fargate is currently available in the us-east-1 (N. Virginia) region.

Launch type

When you create tasks (grouping of containers) and clusters (grouping of tasks), you now have two launch type options: EC2 and Fargate. The default launch type, EC2, is ECS as you knew it before the announcement of Fargate. You need to specify Fargate as the launch type when running a Fargate task.

Even though Fargate abstracts away virtual machines, tasks still must be launched into a cluster. With Fargate, clusters are a logical infrastructure and permissions boundary that allow you to isolate and manage groups of tasks. ECS also supports heterogeneous clusters that are made up of tasks running on both EC2 and Fargate launch types.

The optional, new requiresCompatibilities parameter with FARGATE in the field ensures that your task definition only passes validation if you include Fargate-compatible parameters. Tasks can be flagged as compatible with EC2, Fargate, or both.

"requiresCompatibilities": [
    "FARGATE"
]

Networking

"networkMode": "awsvpc"

In November, we announced the addition of task networking with the network mode awsvpc. By default, ECS uses the bridge network mode. Fargate requires using the awsvpc network mode.

In bridge mode, all of your tasks running on the same instance share the instance’s elastic network interface, which is a virtual network interface, IP address, and security groups.

The awsvpc mode provides this networking support to your tasks natively. You now get the same VPC networking and security controls at the task level that were previously only available with EC2 instances. Each task gets its own elastic networking interface and IP address so that multiple applications or copies of a single application can run on the same port number without any conflicts.

The awsvpc mode also provides a separation of responsibility for tasks. You can get complete control of task placement within your own VPCs, subnets, and the security policies associated with them, even though the underlying infrastructure is managed by Fargate. Also, you can assign different security groups to each task, which gives you more fine-grained security. You can give an application only the permissions it needs.

"portMappings": [
    {
        "containerPort": "3000"
    }
 ]

What else has to change? First, you only specify a containerPort value, not a hostPort value, as there is no host to manage. Your container port is the port that you access on your elastic network interface IP address. Therefore, your container ports in a single task definition file need to be unique.

"environment": [
    {
        "name": "WORDPRESS_DB_HOST",
        "value": "127.0.0.1:3306"
    }
 ]

Additionally, links are not allowed as they are a property of the “bridge” network mode (and are now a legacy feature of Docker). Instead, containers share a network namespace and communicate with each other over the localhost interface. They can be referenced using the following:

localhost/127.0.0.1:<some_port_number>

CPU and memory

"memory": "1024",
 "cpu": "256"

"memory": "1gb",
 "cpu": ".25vcpu"

When launching a task with the EC2 launch type, task performance is influenced by the instance types that you select for your cluster combined with your task definition. If you pick larger instances, your applications make use of the extra resources if there is no contention.

In Fargate, you needed a way to get additional resource information so we created task-level resources. Task-level resources define the maximum amount of memory and cpu that your task can consume.

  • memory can be defined in MB with just the number, or in GB, for example, “1024” or “1gb”.
  • cpu can be defined as the number or in vCPUs, for example, “256” or “.25vcpu”.
    • vCPUs are virtual CPUs. You can look at the memory and vCPUs for instance types to get an idea of what you may have used before.

The memory and CPU options available with Fargate are:

CPUMemory
256 (.25 vCPU)0.5GB, 1GB, 2GB
512 (.5 vCPU)1GB, 2GB, 3GB, 4GB
1024 (1 vCPU)2GB, 3GB, 4GB, 5GB, 6GB, 7GB, 8GB
2048 (2 vCPU)Between 4GB and 16GB in 1GB increments
4096 (4 vCPU)Between 8GB and 30GB in 1GB increments

IAM roles

Because Fargate uses awsvpc mode, you need an Amazon ECS service-linked IAM role named AWSServiceRoleForECS. It provides Fargate with the needed permissions, such as the permission to attach an elastic network interface to your task. After you create your service-linked IAM role, you can delete the remaining roles in your services.

"executionRoleArn": "arn:aws:iam::<your_account_id>:role/ecsTaskExecutionRole"

With the EC2 launch type, an instance role gives the agent the ability to pull, publish, talk to ECS, and so on. With Fargate, the task execution IAM role is only needed if you’re pulling from Amazon ECR or publishing data to Amazon CloudWatch Logs.

The Fargate first-run experience tutorial in the console automatically creates these roles for you.

Volumes

Fargate currently supports non-persistent, empty data volumes for containers. When you define your container, you no longer use the host field and only specify a name.

Load balancers

For awsvpc mode, and therefore for Fargate, use the IP target type instead of the instance target type. You define this in the Amazon EC2 service when creating a load balancer.

If you’re using a Classic Load Balancer, change it to an Application Load Balancer or a Network Load Balancer.

Tip: If you are using an Application Load Balancer, make sure that your tasks are launched in the same VPC and Availability Zones as your load balancer.

Let’s migrate a task definition!

Here is an example NGINX task definition. This type of task definition is what you’re used to if you created one before Fargate was announced. It’s what you would run now with the EC2 launch type.

{
    "containerDefinitions": [
        {
            "name": "nginx",
            "image": "nginx",
            "memory": "512",
            "cpu": "100",
            "essential": true,
            "portMappings": [
                {
                    "hostPort": "80",
                    "containerPort": "80",
                    "protocol": "tcp"
                }
            ],
            "logConfiguration": {
                "logDriver": "awslogs",
                "options": {
                    "awslogs-group": "/ecs/",
                    "awslogs-region": "us-east-1",
                    "awslogs-stream-prefix": "ecs"
                }
            }
        }
    ],
    "family": "nginx-ec2"
}

OK, so now what do you need to do to change it to run with the Fargate launch type?

  • Add FARGATE for requiredCompatibilities (not required, but a good safety check for your task definition).
  • Use awsvpc as the network mode.
  • Just specify the containerPort (the hostPortvalue is the same).
  • Add a task executionRoleARN value to allow logging to CloudWatch.
  • Provide cpu and memory limits for the task.
{
    "requiresCompatibilities": [
        "FARGATE"
    ],
    "containerDefinitions": [
        {
            "name": "nginx",
            "image": "nginx",
            "memory": "512",
            "cpu": "100",
            "essential": true,
            "portMappings": [
                {
                    "containerPort": "80",
                    "protocol": "tcp"
                }
            ],
            "logConfiguration": {
                "logDriver": "awslogs",
                "options": {
                    "awslogs-group": "/ecs/",
                    "awslogs-region": "us-east-1",
                    "awslogs-stream-prefix": "ecs"
                }
            }
        }
    ],
    "networkMode": "awsvpc",
    "executionRoleArn": "arn:aws:iam::<your_account_id>:role/ecsTaskExecutionRole",
    "family": "nginx-fargate",
    "memory": "512",
    "cpu": "256"
}

Are there more examples?

Yep! Head to the AWS Samples GitHub repo. We have several sample task definitions you can try for both the EC2 and Fargate launch types. Contributions are very welcome too :).

 

tiffany jernigan
@tiffanyfayj

Building Blocks of Amazon ECS

Post Syndicated from Tiffany Jernigan original https://aws.amazon.com/blogs/compute/building-blocks-of-amazon-ecs/

So, what’s Amazon Elastic Container Service (ECS)? ECS is a managed service for running containers on AWS, designed to make it easy to run applications in the cloud without worrying about configuring the environment for your code to run in. Using ECS, you can easily deploy containers to host a simple website or run complex distributed microservices using thousands of containers.

Getting started with ECS isn’t too difficult. To fully understand how it works and how you can use it, it helps to understand the basic building blocks of ECS and how they fit together!

Let’s begin with an analogy

Imagine you’re in a virtual reality game with blocks and portals, in which your task is to build kingdoms.

In your spaceship, you pull up a holographic map of your upcoming destination: Nozama, a golden-orange planet. Looking at its various regions, you see that the nearest one is za-southwest-1 (SW Nozama). You set your destination, and use your jump drive to jump to the outer atmosphere of za-southwest-1.

As you approach SW Nozama, you see three portals, 1a, 1b, and 1c. Each portal lets you transport directly to an isolated zone (Availability Zone), where you can start construction on your new kingdom (cluster), Royaume.

With your supply of blocks, you take the portal to 1b, and erect the surrounding walls of your first territory (instance)*.

Before you get ahead of yourself, there are some rules to keep in mind. For your territory to be a part of Royaume, the land ordinance requires construction of a building (container), specifically a castle, from which your territory’s lord (agent)* rules.

You can then create architectural plans (task definitions) to build your developments (tasks), consisting of up to 10 buildings per plan. A development can be built now within this or any territory, or multiple territories.

If you do decide to create more territories, you can either stay here in 1b or take a portal to another location in SW Nozama and start building there.

Amazon EC2 building blocks

We currently provide two launch types: EC2 and Fargate. With Fargate, the Amazon EC2 instances are abstracted away and managed for you. Instead of worrying about ECS container instances, you can just worry about tasks. In this post, the infrastructure components used by ECS that are handled by Fargate are marked with a *.

Instance*

EC2 instances are good ol’ virtual machines (VMs). And yes, don’t worry, you can connect to them (via SSH). Because customers have varying needs in memory, storage, and computing power, many different instance types are offered. Just want to run a small application or try a free trial? Try t2.micro. Want to run memory-optimized workloads? R3 and X1 instances are a couple options. There are many more instance types as well, which cater to various use cases.

AMI*

Sorry if you wanted to immediately march forward, but before you create your instance, you need to choose an AMI. An AMI stands for Amazon Machine Image. What does that mean? Basically, an AMI provides the information required to launch an instance: root volume, launch permissions, and volume-attachment specifications. You can find and choose a Linux or Windows AMI provided by AWS, the user community, the AWS Marketplace (for example, the Amazon ECS-Optimized AMI), or you can create your own.

Region

AWS is divided into regions that are geographic areas around the world (for now it’s just Earth, but maybe someday…). These regions have semi-evocative names such as us-east-1 (N. Virginia), us-west-2 (Oregon), eu-central-1 (Frankfurt), ap-northeast-1 (Tokyo), etc.

Each region is designed to be completely isolated from the others, and consists of multiple, distinct data centers. This creates a “blast radius” for failure so that even if an entire region goes down, the others aren’t affected. Like many AWS services, to start using ECS, you first need to decide the region in which to operate. Typically, this is the region nearest to you or your users.

Availability Zone

AWS regions are subdivided into Availability Zones. A region has at minimum two zones, and up to a handful. Zones are physically isolated from each other, spanning one or more different data centers, but are connected through low-latency, fiber-optic networking, and share some common facilities. EC2 is designed so that the most common failures only affect a single zone to prevent region-wide outages. This means you can achieve high availability in a region by spanning your services across multiple zones and distributing across hosts.

Amazon ECS building blocks

Container

Well, without containers, ECS wouldn’t exist!

Are containers virtual machines?
Nope! Virtual machines virtualize the hardware (benefits), while containers virtualize the operating system (even more benefits!). If you look inside a container, you would see that it is made by processes running on the host, and tied together by kernel constructs like namespaces, cgroups, etc. But you don’t need to bother about that level of detail, at least not in this post!

Why containers?
Containers give you the ability to build, ship, and run your code anywhere!

Before the cloud, you needed to self-host and therefore had to buy machines in addition to setting up and configuring the operating system (OS), and running your code. In the cloud, with virtualization, you can just skip to setting up the OS and running your code. Containers make the process even easier—you can just run your code.

Additionally, all of the dependencies travel in a package with the code, which is called an image. This allows containers to be deployed on any host machine. From the outside, it looks like a host is just holding a bunch of containers. They all look the same, in the sense that they are generic enough to be deployed on any host.

With ECS, you can easily run your containerized code and applications across a managed cluster of EC2 instances.

Are containers a fairly new technology?
The concept of containerization is not new. Its origins date back to 1979 with the creation of chroot. However, it wasn’t until the early 2000s that containers became a major technology. The most significant milestone to date was the release of Docker in 2013, which led to the popularization and widespread adoption of containers.

What does ECS use?
While other container technologies exist (LXC, rkt, etc.), because of its massive adoption and use by our customers, ECS was designed first to work natively with Docker containers.

Container instance*

Yep, you are back to instances. An instance is just slightly more complex in the ECS realm though. Here, it is an ECS container instance that is an EC2 instance running the agent, has a specifically defined IAM policy and role, and has been registered into your cluster.

And as you probably guessed, in these instances, you are running containers. 

AMI*

These container instances can use any AMI as long as it has the following specifications: a modern Linux distribution with the agent and the Docker Daemon with any Docker runtime dependencies running on it.

Want it more simplified? Well, AWS created the Amazon ECS-Optimized AMI for just that. Not only does that AMI come preconfigured with all of the previously mentioned specifications, it’s tested and includes the recommended ecs-init upstart process to run and monitor the agent.

Cluster

An ECS cluster is a grouping of (container) instances* (or tasks in Fargate) that lie within a single region, but can span multiple Availability Zones – it’s even a good idea for redundancy. When launching an instance (or tasks in Fargate), unless specified, it registers with the cluster named “default”. If “default” doesn’t exist, it is created. You can also scale and delete your clusters.

Agent*

The Amazon ECS container agent is a Go program that runs in its own container within each EC2 instance that you use with ECS. (It’s also available open source on GitHub!) The agent is the intermediary component that takes care of the communication between the scheduler and your instances. Want to register your instance into a cluster? (Why wouldn’t you? A cluster is both a logical boundary and provider of pool of resources!) Then you need to run the agent on it.

Task

When you want to start a container, it has to be part of a task. Therefore, you have to create a task first. Succinctly, tasks are a logical grouping of 1 to N containers that run together on the same instance, with N defined by you, up to 10. Let’s say you want to run a custom blog engine. You could put together a web server, an application server, and an in-memory cache, each in their own container. Together, they form a basic frontend unit.

Task definition

Ah, but you cannot create a task directly. You have to create a task definition that tells ECS that “task definition X is composed of this container (and maybe that other container and that other container too!).” It’s kind of like an architectural plan for a city. Some other details it can include are how the containers interact, container CPU and memory constraints, and task permissions using IAM roles.

Then you can tell ECS, “start one task using task definition X.” It might sound like unnecessary planning at first. As soon as you start to deal with multiple tasks, scaling, upgrades, and other “real life” scenarios, you’ll be glad that you have task definitions to keep track of things!

Scheduler*

So, the scheduler schedules… sorry, this should be more helpful, huh? The scheduler is part of the “hosted orchestration layer” provided by ECS. Wait a minute, what do I mean by “hosted orchestration”? Simply put, hosted means that it’s operated by ECS on your behalf, without you having to care about it. Your applications are deployed in containers running on your instances, but the managing of tasks is taken care of by ECS. One less thing to worry about!

Also, the scheduler is the component that decides what (which containers) gets to run where (on which instances), according to a number of constraints. Say that you have a custom blog engine to scale for high availability. You could create a service, which by default, spreads tasks across all zones in the chosen region. And if you want each task to be on a different instance, you can use the distinctInstance task placement constraint. ECS makes sure that not only this happens, but if a task fails, it starts again.

Service

To ensure that you always have your task running without managing it yourself, you can create a service based on the task that you defined and ECS ensures that it stays running. A service is a special construct that says, “at any given time, I want to make sure that N tasks using task definition X1 are running.” If N=1, it just means “make sure that this task is running, and restart it if needed!” And with N>1, you’re basically scaling your application until you hit N, while also ensuring each task is running.

So, what now?

Hopefully you, at the very least, learned a tiny something. All comments are very welcome!

Want to discuss ECS with others? Join the amazon-ecs slack group, which members of the community created and manage.

Also, if you’re interested in learning more about the core concepts of ECS and its relation to EC2, here are some resources:

Pages
Amazon ECS landing page
AWS Fargate landing page
Amazon ECS Getting Started
Nathan Peck’s AWSome ECS

Docs
Amazon EC2
Amazon ECS

Blogs
AWS Compute Blog
AWS Blog

GitHub code
Amazon ECS container agent
Amazon ECS CLI

AWS videos
Learn Amazon ECS
AWS videos
AWS webinars

 

— tiffany

 @tiffanyfayj

 

The re:Invent 2017 Containers After-party Guide

Post Syndicated from Tiffany Jernigan original https://aws.amazon.com/blogs/compute/the-reinvent-2017-containers-after-party-guide/

Feeling uncontainable? re:Invent 2017 might be over, but the containers party doesn’t have to stop. Here are some ways you can keep learning about containers on AWS.

Learn about containers in Austin and New York

Come join AWS this week at KubeCon in Austin, Texas! We’ll be sharing best practices for running Kubernetes on AWS and talking about Amazon ECS, AWS Fargate, and Amazon EKS. Want to take Amazon EKS for a test drive? Sign up for the preview.

We’ll also be talking Containers at the NYC Pop-up Loft during AWS Compute Evolved: Containers Day on December 13th. Register to attend.

Join an upcoming webinar

Didn’t get to attend re:Invent or want to hear a recap? Join our upcoming webinar, What You Missed at re:Invent 2017, on December 11th from 12:00 PM – 12:40 PM PT (3:00 PM – 3:40 PM ET). Register to attend.

Start (or finish) a workshop

All of the containers workshops given at re:Invent are available online. Get comfortable, fire up your browser, and start building!

re:Watch your favorite talks

All of the keynote and breakouts from re:Invent are available to watch on our YouTube playlist. Slides can be found as they are uploaded on the AWS Slideshare. Just slip into your pajamas, make some popcorn, and start watching!

Learn more about what’s new

Andy Jassy announced two big updates to the container landscape at re:Invent, AWS Fargate and Amazon EKS. Here are some resources to help you learn more about all the new features and products we announced, why we built them, and how they work.

AWS Fargate

AWS Fargate is a technology that allows you to run containers without having to manage servers or clusters.

Amazon Elastic Container Service for Kubernetes (Amazon EKS)

Amazon Elastic Container Service for Kubernetes (Amazon EKS) is a managed service that makes it easy for you to run Kubernetes on AWS without needing to configure and operate your own Kubernetes clusters.

We hope you had a great re:Invent and look forward to seeing what you build on AWS in 2018!

– The AWS Containers Team