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How to Patch Linux Workloads on AWS

Post Syndicated from Koen van Blijderveen original https://aws.amazon.com/blogs/security/how-to-patch-linux-workloads-on-aws/

Most malware tries to compromise your systems by using a known vulnerability that the operating system maker has already patched. As best practices to help prevent malware from affecting your systems, you should apply all operating system patches and actively monitor your systems for missing patches.

In this blog post, I show you how to patch Linux workloads using AWS Systems Manager. To accomplish this, I will show you how to use the AWS Command Line Interface (AWS CLI) to:

  1. Launch an Amazon EC2 instance for use with Systems Manager.
  2. Configure Systems Manager to patch your Amazon EC2 Linux instances.

In two previous blog posts (Part 1 and Part 2), I showed how to use the AWS Management Console to perform the necessary steps to patch, inspect, and protect Microsoft Windows workloads. You can implement those same processes for your Linux instances running in AWS by changing the instance tags and types shown in the previous blog posts.

Because most Linux system administrators are more familiar with using a command line, I show how to patch Linux workloads by using the AWS CLI in this blog post. The steps to use the Amazon EBS Snapshot Scheduler and Amazon Inspector are identical for both Microsoft Windows and Linux.

What you should know first

To follow along with the solution in this post, you need one or more Amazon EC2 instances. You may use existing instances or create new instances. For this post, I assume this is an Amazon EC2 for Amazon Linux instance installed from Amazon Machine Images (AMIs).

Systems Manager is a collection of capabilities that helps you automate management tasks for AWS-hosted instances on Amazon EC2 and your on-premises servers. In this post, I use Systems Manager for two purposes: to run remote commands and apply operating system patches. To learn about the full capabilities of Systems Manager, see What Is AWS Systems Manager?

As of Amazon Linux 2017.09, the AMI comes preinstalled with the Systems Manager agent. Systems Manager Patch Manager also supports Red Hat and Ubuntu. To install the agent on these Linux distributions or an older version of Amazon Linux, see Installing and Configuring SSM Agent on Linux Instances.

If you are not familiar with how to launch an Amazon EC2 instance, see Launching an Instance. I also assume you launched or will launch your instance in a private subnet. You must make sure that the Amazon EC2 instance can connect to the internet using a network address translation (NAT) instance or NAT gateway to communicate with Systems Manager. The following diagram shows how you should structure your VPC.

Diagram showing how to structure your VPC

Later in this post, you will assign tasks to a maintenance window to patch your instances with Systems Manager. To do this, the IAM user you are using for this post must have the iam:PassRole permission. This permission allows the IAM user assigning tasks to pass his own IAM permissions to the AWS service. In this example, when you assign a task to a maintenance window, IAM passes your credentials to Systems Manager. You also should authorize your IAM user to use Amazon EC2 and Systems Manager. As mentioned before, you will be using the AWS CLI for most of the steps in this blog post. Our documentation shows you how to get started with the AWS CLI. Make sure you have the AWS CLI installed and configured with an AWS access key and secret access key that belong to an IAM user that have the following AWS managed policies attached to the IAM user you are using for this example: AmazonEC2FullAccess and AmazonSSMFullAccess.

Step 1: Launch an Amazon EC2 Linux instance

In this section, I show you how to launch an Amazon EC2 instance so that you can use Systems Manager with the instance. This step requires you to do three things:

  1. Create an IAM role for Systems Manager before launching your Amazon EC2 instance.
  2. Launch your Amazon EC2 instance with Amazon EBS and the IAM role for Systems Manager.
  3. Add tags to the instances so that you can add your instances to a Systems Manager maintenance window based on tags.

A. Create an IAM role for Systems Manager

Before launching an Amazon EC2 instance, I recommend that you first create an IAM role for Systems Manager, which you will use to update the Amazon EC2 instance. AWS already provides a preconfigured policy that you can use for the new role and it is called AmazonEC2RoleforSSM.

  1. Create a JSON file named trustpolicy-ec2ssm.json that contains the following trust policy. This policy describes which principal (an entity that can take action on an AWS resource) is allowed to assume the role we are going to create. In this example, the principal is the Amazon EC2 service.
    {
      "Version": "2012-10-17",
      "Statement": {
        "Effect": "Allow",
        "Principal": {"Service": "ec2.amazonaws.com"},
        "Action": "sts:AssumeRole"
      }
    }

  1. Use the following command to create a role named EC2SSM that has the AWS managed policy AmazonEC2RoleforSSM attached to it. This generates JSON-based output that describes the role and its parameters, if the command is successful.
    $ aws iam create-role --role-name EC2SSM --assume-role-policy-document file://trustpolicy-ec2ssm.json

  1. Use the following command to attach the AWS managed IAM policy (AmazonEC2RoleforSSM) to your newly created role.
    $ aws iam attach-role-policy --role-name EC2SSM --policy-arn arn:aws:iam::aws:policy/service-role/AmazonEC2RoleforSSM

  1. Use the following commands to create the IAM instance profile and add the role to the instance profile. The instance profile is needed to attach the role we created earlier to your Amazon EC2 instance.
    $ aws iam create-instance-profile --instance-profile-name EC2SSM-IP
    $ aws iam add-role-to-instance-profile --instance-profile-name EC2SSM-IP --role-name EC2SSM

B. Launch your Amazon EC2 instance

To follow along, you need an Amazon EC2 instance that is running Amazon Linux. You can use any existing instance you may have or create a new instance.

When launching a new Amazon EC2 instance, be sure that:

  1. Use the following command to launch a new Amazon EC2 instance using an Amazon Linux AMI available in the US East (N. Virginia) Region (also known as us-east-1). Replace YourKeyPair and YourSubnetId with your information. For more information about creating a key pair, see the create-key-pair documentation. Write down the InstanceId that is in the output because you will need it later in this post.
    $ aws ec2 run-instances --image-id ami-cb9ec1b1 --instance-type t2.micro --key-name YourKeyPair --subnet-id YourSubnetId --iam-instance-profile Name=EC2SSM-IP

  1. If you are using an existing Amazon EC2 instance, you can use the following command to attach the instance profile you created earlier to your instance.
    $ aws ec2 associate-iam-instance-profile --instance-id YourInstanceId --iam-instance-profile Name=EC2SSM-IP

C. Add tags

The final step of configuring your Amazon EC2 instances is to add tags. You will use these tags to configure Systems Manager in Step 2 of this post. For this example, I add a tag named Patch Group and set the value to Linux Servers. I could have other groups of Amazon EC2 instances that I treat differently by having the same tag name but a different tag value. For example, I might have a collection of other servers with the tag name Patch Group with a value of Web Servers.

  • Use the following command to add the Patch Group tag to your Amazon EC2 instance.
    $ aws ec2 create-tags --resources YourInstanceId --tags --tags Key="Patch Group",Value="Linux Servers"

Note: You must wait a few minutes until the Amazon EC2 instance is available before you can proceed to the next section. To make sure your Amazon EC2 instance is online and ready, you can use the following AWS CLI command:

$ aws ec2 describe-instance-status --instance-ids YourInstanceId

At this point, you now have at least one Amazon EC2 instance you can use to configure Systems Manager.

Step 2: Configure Systems Manager

In this section, I show you how to configure and use Systems Manager to apply operating system patches to your Amazon EC2 instances, and how to manage patch compliance.

To start, I provide some background information about Systems Manager. Then, I cover how to:

  1. Create the Systems Manager IAM role so that Systems Manager is able to perform patch operations.
  2. Create a Systems Manager patch baseline and associate it with your instance to define which patches Systems Manager should apply.
  3. Define a maintenance window to make sure Systems Manager patches your instance when you tell it to.
  4. Monitor patch compliance to verify the patch state of your instances.

You must meet two prerequisites to use Systems Manager to apply operating system patches. First, you must attach the IAM role you created in the previous section, EC2SSM, to your Amazon EC2 instance. Second, you must install the Systems Manager agent on your Amazon EC2 instance. If you have used a recent Amazon Linux AMI, Amazon has already installed the Systems Manager agent on your Amazon EC2 instance. You can confirm this by logging in to an Amazon EC2 instance and checking the Systems Manager agent log files that are located at /var/log/amazon/ssm/.

To install the Systems Manager agent on an instance that does not have the agent preinstalled or if you want to use the Systems Manager agent on your on-premises servers, see Installing and Configuring the Systems Manager Agent on Linux Instances. If you forgot to attach the newly created role when launching your Amazon EC2 instance or if you want to attach the role to already running Amazon EC2 instances, see Attach an AWS IAM Role to an Existing Amazon EC2 Instance by Using the AWS CLI or use the AWS Management Console.

A. Create the Systems Manager IAM role

For a maintenance window to be able to run any tasks, you must create a new role for Systems Manager. This role is a different kind of role than the one you created earlier: this role will be used by Systems Manager instead of Amazon EC2. Earlier, you created the role, EC2SSM, with the policy, AmazonEC2RoleforSSM, which allowed the Systems Manager agent on your instance to communicate with Systems Manager. In this section, you need a new role with the policy, AmazonSSMMaintenanceWindowRole, so that the Systems Manager service can execute commands on your instance.

To create the new IAM role for Systems Manager:

  1. Create a JSON file named trustpolicy-maintenancewindowrole.json that contains the following trust policy. This policy describes which principal is allowed to assume the role you are going to create. This trust policy allows not only Amazon EC2 to assume this role, but also Systems Manager.
    {
       "Version":"2012-10-17",
       "Statement":[
          {
             "Sid":"",
             "Effect":"Allow",
             "Principal":{
                "Service":[
                   "ec2.amazonaws.com",
                   "ssm.amazonaws.com"
               ]
             },
             "Action":"sts:AssumeRole"
          }
       ]
    }

  1. Use the following command to create a role named MaintenanceWindowRole that has the AWS managed policy, AmazonSSMMaintenanceWindowRole, attached to it. This command generates JSON-based output that describes the role and its parameters, if the command is successful.
    $ aws iam create-role --role-name MaintenanceWindowRole --assume-role-policy-document file://trustpolicy-maintenancewindowrole.json

  1. Use the following command to attach the AWS managed IAM policy (AmazonEC2RoleforSSM) to your newly created role.
    $ aws iam attach-role-policy --role-name MaintenanceWindowRole --policy-arn arn:aws:iam::aws:policy/service-role/AmazonSSMMaintenanceWindowRole

B. Create a Systems Manager patch baseline and associate it with your instance

Next, you will create a Systems Manager patch baseline and associate it with your Amazon EC2 instance. A patch baseline defines which patches Systems Manager should apply to your instance. Before you can associate the patch baseline with your instance, though, you must determine if Systems Manager recognizes your Amazon EC2 instance. Use the following command to list all instances managed by Systems Manager. The --filters option ensures you look only for your newly created Amazon EC2 instance.

$ aws ssm describe-instance-information --filters Key=InstanceIds,Values= YourInstanceId

{
    "InstanceInformationList": [
        {
            "IsLatestVersion": true,
            "ComputerName": "ip-10-50-2-245",
            "PingStatus": "Online",
            "InstanceId": "YourInstanceId",
            "IPAddress": "10.50.2.245",
            "ResourceType": "EC2Instance",
            "AgentVersion": "2.2.120.0",
            "PlatformVersion": "2017.09",
            "PlatformName": "Amazon Linux AMI",
            "PlatformType": "Linux",
            "LastPingDateTime": 1515759143.826
        }
    ]
}

If your instance is missing from the list, verify that:

  1. Your instance is running.
  2. You attached the Systems Manager IAM role, EC2SSM.
  3. You deployed a NAT gateway in your public subnet to ensure your VPC reflects the diagram shown earlier in this post so that the Systems Manager agent can connect to the Systems Manager internet endpoint.
  4. The Systems Manager agent logs don’t include any unaddressed errors.

Now that you have checked that Systems Manager can manage your Amazon EC2 instance, it is time to create a patch baseline. With a patch baseline, you define which patches are approved to be installed on all Amazon EC2 instances associated with the patch baseline. The Patch Group resource tag you defined earlier will determine to which patch group an instance belongs. If you do not specifically define a patch baseline, the default AWS-managed patch baseline is used.

To create a patch baseline:

  1. Use the following command to create a patch baseline named AmazonLinuxServers. With approval rules, you can determine the approved patches that will be included in your patch baseline. In this example, you add all Critical severity patches to the patch baseline as soon as they are released, by setting the Auto approval delay to 0 days. By setting the Auto approval delay to 2 days, you add to this patch baseline the Important, Medium, and Low severity patches two days after they are released.
    $ aws ssm create-patch-baseline --name "AmazonLinuxServers" --description "Baseline containing all updates for Amazon Linux" --operating-system AMAZON_LINUX --approval-rules "PatchRules=[{PatchFilterGroup={PatchFilters=[{Values=[Critical],Key=SEVERITY}]},ApproveAfterDays=0,ComplianceLevel=CRITICAL},{PatchFilterGroup={PatchFilters=[{Values=[Important,Medium,Low],Key=SEVERITY}]},ApproveAfterDays=2,ComplianceLevel=HIGH}]"
    
    {
        "BaselineId": "YourBaselineId"
    }

  1. Use the following command to register the patch baseline you created with your instance. To do so, you use the Patch Group tag that you added to your Amazon EC2 instance.
    $ aws ssm register-patch-baseline-for-patch-group --baseline-id YourPatchBaselineId --patch-group "Linux Servers"
    
    {
        "PatchGroup": "Linux Servers",
        "BaselineId": "YourBaselineId"
    }

C.  Define a maintenance window

Now that you have successfully set up a role, created a patch baseline, and registered your Amazon EC2 instance with your patch baseline, you will define a maintenance window so that you can control when your Amazon EC2 instances will receive patches. By creating multiple maintenance windows and assigning them to different patch groups, you can make sure your Amazon EC2 instances do not all reboot at the same time.

To define a maintenance window:

  1. Use the following command to define a maintenance window. In this example command, the maintenance window will start every Saturday at 10:00 P.M. UTC. It will have a duration of 4 hours and will not start any new tasks 1 hour before the end of the maintenance window.
    $ aws ssm create-maintenance-window --name SaturdayNight --schedule "cron(0 0 22 ? * SAT *)" --duration 4 --cutoff 1 --allow-unassociated-targets
    
    {
        "WindowId": "YourMaintenanceWindowId"
    }

For more information about defining a cron-based schedule for maintenance windows, see Cron and Rate Expressions for Maintenance Windows.

  1. After defining the maintenance window, you must register the Amazon EC2 instance with the maintenance window so that Systems Manager knows which Amazon EC2 instance it should patch in this maintenance window. You can register the instance by using the same Patch Group tag you used to associate the Amazon EC2 instance with the AWS-provided patch baseline, as shown in the following command.
    $ aws ssm register-target-with-maintenance-window --window-id YourMaintenanceWindowId --resource-type INSTANCE --targets "Key=tag:Patch Group,Values=Linux Servers"
    
    {
        "WindowTargetId": "YourWindowTargetId"
    }

  1. Assign a task to the maintenance window that will install the operating system patches on your Amazon EC2 instance. The following command includes the following options.
    1. name is the name of your task and is optional. I named mine Patching.
    2. task-arn is the name of the task document you want to run.
    3. max-concurrency allows you to specify how many of your Amazon EC2 instances Systems Manager should patch at the same time. max-errors determines when Systems Manager should abort the task. For patching, this number should not be too low, because you do not want your entire patch task to stop on all instances if one instance fails. You can set this, for example, to 20%.
    4. service-role-arn is the Amazon Resource Name (ARN) of the AmazonSSMMaintenanceWindowRole role you created earlier in this blog post.
    5. task-invocation-parameters defines the parameters that are specific to the AWS-RunPatchBaseline task document and tells Systems Manager that you want to install patches with a timeout of 600 seconds (10 minutes).
      $ aws ssm register-task-with-maintenance-window --name "Patching" --window-id "YourMaintenanceWindowId" --targets "Key=WindowTargetIds,Values=YourWindowTargetId" --task-arn AWS-RunPatchBaseline --service-role-arn "arn:aws:iam::123456789012:role/MaintenanceWindowRole" --task-type "RUN_COMMAND" --task-invocation-parameters "RunCommand={Comment=,TimeoutSeconds=600,Parameters={SnapshotId=[''],Operation=[Install]}}" --max-concurrency "500" --max-errors "20%"
      
      {
          "WindowTaskId": "YourWindowTaskId"
      }

Now, you must wait for the maintenance window to run at least once according to the schedule you defined earlier. If your maintenance window has expired, you can check the status of any maintenance tasks Systems Manager has performed by using the following command.

$ aws ssm describe-maintenance-window-executions --window-id "YourMaintenanceWindowId"

{
    "WindowExecutions": [
        {
            "Status": "SUCCESS",
            "WindowId": "YourMaintenanceWindowId",
            "WindowExecutionId": "b594984b-430e-4ffa-a44c-a2e171de9dd3",
            "EndTime": 1515766467.487,
            "StartTime": 1515766457.691
        }
    ]
}

D.  Monitor patch compliance

You also can see the overall patch compliance of all Amazon EC2 instances using the following command in the AWS CLI.

$ aws ssm list-compliance-summaries

This command shows you the number of instances that are compliant with each category and the number of instances that are not in JSON format.

You also can see overall patch compliance by choosing Compliance under Insights in the navigation pane of the Systems Manager console. You will see a visual representation of how many Amazon EC2 instances are up to date, how many Amazon EC2 instances are noncompliant, and how many Amazon EC2 instances are compliant in relation to the earlier defined patch baseline.

Screenshot of the Compliance page of the Systems Manager console

In this section, you have set everything up for patch management on your instance. Now you know how to patch your Amazon EC2 instance in a controlled manner and how to check if your Amazon EC2 instance is compliant with the patch baseline you have defined. Of course, I recommend that you apply these steps to all Amazon EC2 instances you manage.

Summary

In this blog post, I showed how to use Systems Manager to create a patch baseline and maintenance window to keep your Amazon EC2 Linux instances up to date with the latest security patches. Remember that by creating multiple maintenance windows and assigning them to different patch groups, you can make sure your Amazon EC2 instances do not all reboot at the same time.

If you have comments about this post, submit them in the “Comments” section below. If you have questions about or issues implementing any part of this solution, start a new thread on the Amazon EC2 forum or contact AWS Support.

– Koen

Task Networking in AWS Fargate

Post Syndicated from Nathan Peck original https://aws.amazon.com/blogs/compute/task-networking-in-aws-fargate/

AWS Fargate is a technology that allows you to focus on running your application without needing to provision, monitor, or manage the underlying compute infrastructure. You package your application into a Docker container that you can then launch using your container orchestration tool of choice.

Fargate allows you to use containers without being responsible for Amazon EC2 instances, similar to how EC2 allows you to run VMs without managing physical infrastructure. Currently, Fargate provides support for Amazon Elastic Container Service (Amazon ECS). Support for Amazon Elastic Container Service for Kubernetes (Amazon EKS) will be made available in the near future.

Despite offloading the responsibility for the underlying instances, Fargate still gives you deep control over configuration of network placement and policies. This includes the ability to use many networking fundamentals such as Amazon VPC and security groups.

This post covers how to take advantage of the different ways of networking your containers in Fargate when using ECS as your orchestration platform, with a focus on how to do networking securely.

The first step to running any application in Fargate is defining an ECS task for Fargate to launch. A task is a logical group of one or more Docker containers that are deployed with specified settings. When running a task in Fargate, there are two different forms of networking to consider:

  • Container (local) networking
  • External networking

Container Networking

Container networking is often used for tightly coupled application components. Perhaps your application has a web tier that is responsible for serving static content as well as generating some dynamic HTML pages. To generate these dynamic pages, it has to fetch information from another application component that has an HTTP API.

One potential architecture for such an application is to deploy the web tier and the API tier together as a pair and use local networking so the web tier can fetch information from the API tier.

If you are running these two components as two processes on a single EC2 instance, the web tier application process could communicate with the API process on the same machine by using the local loopback interface. The local loopback interface has a special IP address of 127.0.0.1 and hostname of localhost.

By making a networking request to this local interface, it bypasses the network interface hardware and instead the operating system just routes network calls from one process to the other directly. This gives the web tier a fast and efficient way to fetch information from the API tier with almost no networking latency.

In Fargate, when you launch multiple containers as part of a single task, they can also communicate with each other over the local loopback interface. Fargate uses a special container networking mode called awsvpc, which gives all the containers in a task a shared elastic network interface to use for communication.

If you specify a port mapping for each container in the task, then the containers can communicate with each other on that port. For example the following task definition could be used to deploy the web tier and the API tier:

{
  "family": "myapp"
  "containerDefinitions": [
    {
      "name": "web",
      "image": "my web image url",
      "portMappings": [
        {
          "containerPort": 80
        }
      ],
      "memory": 500,
      "cpu": 10,
      "esssential": true
    },
    {
      "name": "api",
      "image": "my api image url",
      "portMappings": [
        {
          "containerPort": 8080
        }
      ],
      "cpu": 10,
      "memory": 500,
      "essential": true
    }
  ]
}

ECS, with Fargate, is able to take this definition and launch two containers, each of which is bound to a specific static port on the elastic network interface for the task.

Because each Fargate task has its own isolated networking stack, there is no need for dynamic ports to avoid port conflicts between different tasks as in other networking modes. The static ports make it easy for containers to communicate with each other. For example, the web container makes a request to the API container using its well-known static port:

curl 127.0.0.1:8080/my-endpoint

This sends a local network request, which goes directly from one container to the other over the local loopback interface without traversing the network. This deployment strategy allows for fast and efficient communication between two tightly coupled containers. But most application architectures require more than just internal local networking.

External Networking

External networking is used for network communications that go outside the task to other servers that are not part of the task, or network communications that originate from other hosts on the internet and are directed to the task.

Configuring external networking for a task is done by modifying the settings of the VPC in which you launch your tasks. A VPC is a fundamental tool in AWS for controlling the networking capabilities of resources that you launch on your account.

When setting up a VPC, you create one or more subnets, which are logical groups that your resources can be placed into. Each subnet has an Availability Zone and its own route table, which defines rules about how network traffic operates for that subnet. There are two main types of subnets: public and private.

Public subnets

A public subnet is a subnet that has an associated internet gateway. Fargate tasks in that subnet are assigned both private and public IP addresses:


A browser or other client on the internet can send network traffic to the task via the internet gateway using its public IP address. The tasks can also send network traffic to other servers on the internet because the route table can route traffic out via the internet gateway.

If tasks want to communicate directly with each other, they can use each other’s private IP address to send traffic directly from one to the other so that it stays inside the subnet without going out to the internet gateway and back in.

Private subnets

A private subnet does not have direct internet access. The Fargate tasks inside the subnet don’t have public IP addresses, only private IP addresses. Instead of an internet gateway, a network address translation (NAT) gateway is attached to the subnet:

 

There is no way for another server or client on the internet to reach your tasks directly, because they don’t even have an address or a direct route to reach them. This is a great way to add another layer of protection for internal tasks that handle sensitive data. Those tasks are protected and can’t receive any inbound traffic at all.

In this configuration, the tasks can still communicate to other servers on the internet via the NAT gateway. They would appear to have the IP address of the NAT gateway to the recipient of the communication. If you run a Fargate task in a private subnet, you must add this NAT gateway. Otherwise, Fargate can’t make a network request to Amazon ECR to download the container image, or communicate with Amazon CloudWatch to store container metrics.

Load balancers

If you are running a container that is hosting internet content in a private subnet, you need a way for traffic from the public to reach the container. This is generally accomplished by using a load balancer such as an Application Load Balancer or a Network Load Balancer.

ECS integrates tightly with AWS load balancers by automatically configuring a service-linked load balancer to send network traffic to containers that are part of the service. When each task starts, the IP address of its elastic network interface is added to the load balancer’s configuration. When the task is being shut down, network traffic is safely drained from the task before removal from the load balancer.

To get internet traffic to containers using a load balancer, the load balancer is placed into a public subnet. ECS configures the load balancer to forward traffic to the container tasks in the private subnet:

This configuration allows your tasks in Fargate to be safely isolated from the rest of the internet. They can still initiate network communication with external resources via the NAT gateway, and still receive traffic from the public via the Application Load Balancer that is in the public subnet.

Another potential use case for a load balancer is for internal communication from one service to another service within the private subnet. This is typically used for a microservice deployment, in which one service such as an internet user account service needs to communicate with an internal service such as a password service. Obviously, it is undesirable for the password service to be directly accessible on the internet, so using an internet load balancer would be a major security vulnerability. Instead, this can be accomplished by hosting an internal load balancer within the private subnet:

With this approach, one container can distribute requests across an Auto Scaling group of other private containers via the internal load balancer, ensuring that the network traffic stays safely protected within the private subnet.

Best Practices for Fargate Networking

Determine whether you should use local task networking

Local task networking is ideal for communicating between containers that are tightly coupled and require maximum networking performance between them. However, when you deploy one or more containers as part of the same task they are always deployed together so it removes the ability to independently scale different types of workload up and down.

In the example of the application with a web tier and an API tier, it may be the case that powering the application requires only two web tier containers but 10 API tier containers. If local container networking is used between these two container types, then an extra eight unnecessary web tier containers would end up being run instead of allowing the two different services to scale independently.

A better approach would be to deploy the two containers as two different services, each with its own load balancer. This allows clients to communicate with the two web containers via the web service’s load balancer. The web service could distribute requests across the eight backend API containers via the API service’s load balancer.

Run internet tasks that require internet access in a public subnet

If you have tasks that require internet access and a lot of bandwidth for communication with other services, it is best to run them in a public subnet. Give them public IP addresses so that each task can communicate with other services directly.

If you run these tasks in a private subnet, then all their outbound traffic has to go through an NAT gateway. AWS NAT gateways support up to 10 Gbps of burst bandwidth. If your bandwidth requirements go over this, then all task networking starts to get throttled. To avoid this, you could distribute the tasks across multiple private subnets, each with their own NAT gateway. It can be easier to just place the tasks into a public subnet, if possible.

Avoid using a public subnet or public IP addresses for private, internal tasks

If you are running a service that handles private, internal information, you should not put it into a public subnet or use a public IP address. For example, imagine that you have one task, which is an API gateway for authentication and access control. You have another background worker task that handles sensitive information.

The intended access pattern is that requests from the public go to the API gateway, which then proxies request to the background task only if the request is from an authenticated user. If the background task is in a public subnet and has a public IP address, then it could be possible for an attacker to bypass the API gateway entirely. They could communicate directly to the background task using its public IP address, without being authenticated.

Conclusion

Fargate gives you a way to run containerized tasks directly without managing any EC2 instances, but you still have full control over how you want networking to work. You can set up containers to talk to each other over the local network interface for maximum speed and efficiency. For running workloads that require privacy and security, use a private subnet with public internet access locked down. Or, for simplicity with an internet workload, you can just use a public subnet and give your containers a public IP address.

To deploy one of these Fargate task networking approaches, check out some sample CloudFormation templates showing how to configure the VPC, subnets, and load balancers.

If you have questions or suggestions, please comment below.

AWS PrivateLink Update – VPC Endpoints for Your Own Applications & Services

Post Syndicated from Jeff Barr original https://aws.amazon.com/blogs/aws/aws-privatelink-update-vpc-endpoints-for-your-own-applications-services/

Earlier this month, my colleague Colm MacCárthaigh told you about AWS PrivateLink and showed you how to use it to access AWS services such as Amazon Kinesis Streams, AWS Service Catalog, EC2 Systems Manager, the EC2 APIs, and the ELB APIs by way of VPC Endpoints. The endpoint (represented by one or more Elastic Network Interfaces or ENIs) resides within your VPC and has IP addresses drawn from the VPC’s subnets, without the need for an Internet or NAT Gateway. This model is clear and easy to understand, not to mention secure and scalable!

Endpoints for Private Connectivity
Today we are building upon the initial launch and extending the PrivateLink model, allowing you to set up and use VPC Endpoints to access your own services and those made available by others. Even before we launched PrivateLink for AWS services, we had a lot of requests for this feature, so I expect it to be pretty popular. For example, one customer told us that they plan to create hundreds of VPCs, each hosting and providing a single microservice (read Microservices on AWS to learn more).

Companies can now create services and offer them for sale to other AWS customers, for access via a private connection. They create a service that accepts TCP traffic, host it behind a Network Load Balancer, and then make the service available, either directly or in AWS Marketplace. They will be notified of new subscription requests and can choose to accept or reject each one. I expect that this feature will be used to create a strong, vibrant ecosystem of service providers in 2018.

The service provider and the service consumer run in separate VPCs and AWS accounts and communicate solely through the endpoint, with all traffic flowing across Amazon’s private network. Service consumers don’t have to worry about overlapping IP addresses, arrange for VPC peering, or use a VPC Gateway. You can also use AWS Direct Connect to connect your existing data center to one of your VPCs in order to allow your cloud-based applications to access services running on-premises, or vice versa.

Providing and Consuming Services
This new feature puts a lot of power at your fingertips. You can set it all up using the VPC APIs, the VPC CLI, or the AWS Management Console. I’ll use the console, and will show you how to provide and then consume a service. I am going to do both within a single AWS account, but that’s just for demo purposes.

Let’s talk about providing a service. It must run behind a Network Load Balancer and must be accessible over TCP. It can be hosted on EC2 instances, ECS containers, or on-premises (configured as an IP target), and should be able to scale in order to meet the expected level of demand. For low latency and fault tolerance, we recommend using an NLB with targets in every AZ of its region. Here’s mine:

I open up the VPC Console and navigate to Endpoint Services, then click on Create Endpoint Service:

I choose my NLB (just one in this case, but I can choose two or more and they will be mapped to consumers on a round-robin basis). By clicking on Acceptance required, I get to control access to my endpoint on a request-by-request basis:

I click on Create service and my service is ready immediately:

If I was going to make this service available in AWS Marketplace, I would go ahead and create a listing now. Since I am going to be the producer and the consumer in this blog post, I’ll skip that step. I will, however, copy the Service name for use in the next step.

I return to the VPC Dashboard and navigate to Endpoints, then click on Create endpoint. Then I select Find service by name, paste the service name, and click on Verify to move ahead. Then I select the desired AZs, and a subnet in each one, pick my security groups, and click on Create endpoint:

Because I checked Acceptance required when I created the endpoint service, the connection is pending acceptance:

Back on the endpoint service side (typically in a separate AWS account), I can see and accept the pending request:

The endpoint becomes available and ready to use within a minute or so. If I was creating a service and selling access on a paid basis, I would accept the request as part of a larger, and perhaps automated, onboarding workflow for a new customer.

On the consumer side, my new endpoint is accessible via DNS name:

Services provided by AWS and services in AWS Marketplace are accessible through split-horizon DNS. Accessing the service through this name will resolve to the “best” endpoint, taking Region and Availability Zone into consideration.

In the Marketplace
As I noted earlier, this new PrivateLink feature creates an opportunity for new and existing sellers in AWS Marketplace. The following SaaS offerings are already available as endpoints and I expect many more to follow (read Sell on AWS Marketplace to get started):

CA TechnologiesCA App Experience Analytics Essentials.

Aqua SecurityAqua Container Image Security Scanner.

DynatraceCloud-Native Monitoring powered by AI.

Cisco StealthwatchPublic Cloud Monitoring – Metered, Public Cloud Monitoring – Contracts.

SigOptML Optimization & Tuning.

Available Today
This new PrivateLink feature is available now and you can start using it today!

Jeff;

 

Access Resources in a VPC from AWS CodeBuild Builds

Post Syndicated from John Pignata original https://aws.amazon.com/blogs/devops/access-resources-in-a-vpc-from-aws-codebuild-builds/

John Pignata, Startup Solutions Architect, Amazon Web Services

In this blog post we’re going to discuss a new AWS CodeBuild feature that is available starting today. CodeBuild builds can now access resources in a VPC directly without these resources being exposed to the public internet. These resources include Amazon Relational Database Service (Amazon RDS) databases, Amazon ElastiCache clusters, internal services running on Amazon Elastic Compute Cloud (Amazon EC2), and Amazon EC2 Container Service (Amazon ECS), or any service endpoints that are only reachable from within a specific VPC.

CodeBuild is a fully managed build service that compiles source code, runs tests, and produces software packages that are ready to deploy. As part of the build process, developers often require access to resources that should be isolated from the public Internet. Now CodeBuild builds can be optionally configured to have VPC connectivity and access these resources directly.

Accessing Resources in a VPC

You can configure builds to have access to a VPC when you create a CodeBuild project or you can update an existing CodeBuild project with VPC configuration attributes. Here’s how it looks in the console:

 

To configure VPC connectivity: select a VPC, one or more subnets within that VPC, and one or more VPC security groups that CodeBuild should apply when attaching to your VPC. Once configured, commands running as part of your build will be able to access resources in your VPC without transiting across the public Internet.

Use Cases

The availability of VPC connectivity from CodeBuild builds unlocks many potential uses. For example, you can:

  • Run integration tests from your build against data in an Amazon RDS instance that’s isolated on a private subnet.
  • Query data in an ElastiCache cluster directly from tests.
  • Interact with internal web services hosted on Amazon EC2, Amazon ECS, or services that use internal Elastic Load Balancing.
  • Retrieve dependencies from self-hosted, internal artifact repositories such as PyPI for Python, Maven for Java, npm for Node.js, and so on.
  • Access objects in an Amazon S3 bucket configured to allow access only through a VPC endpoint.
  • Query external web services that require fixed IP addresses through the Elastic IP address of the NAT gateway associated with your subnet(s).

… and more! Your builds can now access any resource that’s hosted in your VPC without any compromise on network isolation.

Internet Connectivity

CodeBuild requires access to resources on the public Internet to successfully execute builds. At a minimum, it must be able to reach your source repository system (such as AWS CodeCommit, GitHub, Bitbucket), Amazon Simple Storage Service (Amazon S3) to deliver build artifacts, and Amazon CloudWatch Logs to stream logs from the build process. The interface attached to your VPC will not be assigned a public IP address so to enable Internet access from your builds, you will need to set up a managed NAT Gateway or NAT instance for the subnets you configure. You must also ensure your security groups allow outbound access to these services.

IP Address Space

Each running build will be assigned an IP address from one of the subnets in your VPC that you designate for CodeBuild to use. As CodeBuild scales to meet your build volume, ensure that you select subnets with enough address space to accommodate your expected number of concurrent builds.

Service Role Permissions

CodeBuild requires new permissions in order to manage network interfaces on your VPCs. If you create a service role for your new projects, these permissions will be included in that role’s policy automatically. For existing service roles, you can edit the policy document to include the additional actions. For the full policy document to apply to your service role, see Advanced Setup in the CodeBuild documentation.

For more information, see VPC Support in the CodeBuild documentation. We hope you find the ability to access internal resources on a VPC useful in your build processes! If you have any questions or feedback, feel free to reach out to us through the AWS CodeBuild forum or leave a comment!

How to Patch, Inspect, and Protect Microsoft Windows Workloads on AWS—Part 1

Post Syndicated from Koen van Blijderveen original https://aws.amazon.com/blogs/security/how-to-patch-inspect-and-protect-microsoft-windows-workloads-on-aws-part-1/

Most malware tries to compromise your systems by using a known vulnerability that the maker of the operating system has already patched. To help prevent malware from affecting your systems, two security best practices are to apply all operating system patches to your systems and actively monitor your systems for missing patches. In case you do need to recover from a malware attack, you should make regular backups of your data.

In today’s blog post (Part 1 of a two-part post), I show how to keep your Amazon EC2 instances that run Microsoft Windows up to date with the latest security patches by using Amazon EC2 Systems Manager. Tomorrow in Part 2, I show how to take regular snapshots of your data by using Amazon EBS Snapshot Scheduler and how to use Amazon Inspector to check if your EC2 instances running Microsoft Windows contain any common vulnerabilities and exposures (CVEs).

What you should know first

To follow along with the solution in this post, you need one or more EC2 instances. You may use existing instances or create new instances. For the blog post, I assume this is an EC2 for Microsoft Windows Server 2012 R2 instance installed from the Amazon Machine Images (AMIs). If you are not familiar with how to launch an EC2 instance, see Launching an Instance. I also assume you launched or will launch your instance in a private subnet. A private subnet is not directly accessible via the internet, and access to it requires either a VPN connection to your on-premises network or a jump host in a public subnet (a subnet with access to the internet). You must make sure that the EC2 instance can connect to the internet using a network address translation (NAT) instance or NAT gateway to communicate with Systems Manager and Amazon Inspector. The following diagram shows how you should structure your Amazon Virtual Private Cloud (VPC). You should also be familiar with Restoring an Amazon EBS Volume from a Snapshot and Attaching an Amazon EBS Volume to an Instance.

Later on, you will assign tasks to a maintenance window to patch your instances with Systems Manager. To do this, the AWS Identity and Access Management (IAM) user you are using for this post must have the iam:PassRole permission. This permission allows this IAM user to assign tasks to pass their own IAM permissions to the AWS service. In this example, when you assign a task to a maintenance window, IAM passes your credentials to Systems Manager. This safeguard ensures that the user cannot use the creation of tasks to elevate their IAM privileges because their own IAM privileges limit which tasks they can run against an EC2 instance. You should also authorize your IAM user to use EC2, Amazon Inspector, Amazon CloudWatch, and Systems Manager. You can achieve this by attaching the following AWS managed policies to the IAM user you are using for this example: AmazonInspectorFullAccess, AmazonEC2FullAccess, and AmazonSSMFullAccess.

Architectural overview

The following diagram illustrates the components of this solution’s architecture.

Diagram showing the components of this solution's architecture

For this blog post, Microsoft Windows EC2 is Amazon EC2 for Microsoft Windows Server 2012 R2 instances with attached Amazon Elastic Block Store (Amazon EBS) volumes, which are running in your VPC. These instances may be standalone Windows instances running your Windows workloads, or you may have joined them to an Active Directory domain controller. For instances joined to a domain, you can be using Active Directory running on an EC2 for Windows instance, or you can use AWS Directory Service for Microsoft Active Directory.

Amazon EC2 Systems Manager is a scalable tool for remote management of your EC2 instances. You will use the Systems Manager Run Command to install the Amazon Inspector agent. The agent enables EC2 instances to communicate with the Amazon Inspector service and run assessments, which I explain in detail later in this blog post. You also will create a Systems Manager association to keep your EC2 instances up to date with the latest security patches.

You can use the EBS Snapshot Scheduler to schedule automated snapshots at regular intervals. You will use it to set up regular snapshots of your Amazon EBS volumes. EBS Snapshot Scheduler is a prebuilt solution by AWS that you will deploy in your AWS account. With Amazon EBS snapshots, you pay only for the actual data you store. Snapshots save only the data that has changed since the previous snapshot, which minimizes your cost.

You will use Amazon Inspector to run security assessments on your EC2 for Windows Server instance. In this post, I show how to assess if your EC2 for Windows Server instance is vulnerable to any of the more than 50,000 CVEs registered with Amazon Inspector.

In today’s and tomorrow’s posts, I show you how to:

  1. Launch an EC2 instance with an IAM role, Amazon EBS volume, and tags that Systems Manager and Amazon Inspector will use.
  2. Configure Systems Manager to install the Amazon Inspector agent and patch your EC2 instances.
  3. Take EBS snapshots by using EBS Snapshot Scheduler to automate snapshots based on instance tags.
  4. Use Amazon Inspector to check if your EC2 instances running Microsoft Windows contain any common vulnerabilities and exposures (CVEs).

Step 1: Launch an EC2 instance

In this section, I show you how to launch your EC2 instances so that you can use Systems Manager with the instances and use instance tags with EBS Snapshot Scheduler to automate snapshots. This requires three things:

  • Create an IAM role for Systems Manager before launching your EC2 instance.
  • Launch your EC2 instance with Amazon EBS and the IAM role for Systems Manager.
  • Add tags to instances so that you can automate policies for which instances you take snapshots of and when.

Create an IAM role for Systems Manager

Before launching your EC2 instance, I recommend that you first create an IAM role for Systems Manager, which you will use to update the EC2 instance you will launch. AWS already provides a preconfigured policy that you can use for your new role, and it is called AmazonEC2RoleforSSM.

  1. Sign in to the IAM console and choose Roles in the navigation pane. Choose Create new role.
    Screenshot of choosing "Create role"
  2. In the role-creation workflow, choose AWS service > EC2 > EC2 to create a role for an EC2 instance.
    Screenshot of creating a role for an EC2 instance
  3. Choose the AmazonEC2RoleforSSM policy to attach it to the new role you are creating.
    Screenshot of attaching the AmazonEC2RoleforSSM policy to the new role you are creating
  4. Give the role a meaningful name (I chose EC2SSM) and description, and choose Create role.
    Screenshot of giving the role a name and description

Launch your EC2 instance

To follow along, you need an EC2 instance that is running Microsoft Windows Server 2012 R2 and that has an Amazon EBS volume attached. You can use any existing instance you may have or create a new instance.

When launching your new EC2 instance, be sure that:

  • The operating system is Microsoft Windows Server 2012 R2.
  • You attach at least one Amazon EBS volume to the EC2 instance.
  • You attach the newly created IAM role (EC2SSM).
  • The EC2 instance can connect to the internet through a network address translation (NAT) gateway or a NAT instance.
  • You create the tags shown in the following screenshot (you will use them later).

If you are using an already launched EC2 instance, you can attach the newly created role as described in Easily Replace or Attach an IAM Role to an Existing EC2 Instance by Using the EC2 Console.

Add tags

The final step of configuring your EC2 instances is to add tags. You will use these tags to configure Systems Manager in Step 2 of this blog post and to configure Amazon Inspector in Part 2. For this example, I add a tag key, Patch Group, and set the value to Windows Servers. I could have other groups of EC2 instances that I treat differently by having the same tag key but a different tag value. For example, I might have a collection of other servers with the Patch Group tag key with a value of IAS Servers.

Screenshot of adding tags

Note: You must wait a few minutes until the EC2 instance becomes available before you can proceed to the next section.

At this point, you now have at least one EC2 instance you can use to configure Systems Manager, use EBS Snapshot Scheduler, and use Amazon Inspector.

Note: If you have a large number of EC2 instances to tag, you may want to use the EC2 CreateTags API rather than manually apply tags to each instance.

Step 2: Configure Systems Manager

In this section, I show you how to use Systems Manager to apply operating system patches to your EC2 instances, and how to manage patch compliance.

To start, I will provide some background information about Systems Manager. Then, I will cover how to:

  • Create the Systems Manager IAM role so that Systems Manager is able to perform patch operations.
  • Associate a Systems Manager patch baseline with your instance to define which patches Systems Manager should apply.
  • Define a maintenance window to make sure Systems Manager patches your instance when you tell it to.
  • Monitor patch compliance to verify the patch state of your instances.

Systems Manager is a collection of capabilities that helps you automate management tasks for AWS-hosted instances on EC2 and your on-premises servers. In this post, I use Systems Manager for two purposes: to run remote commands and apply operating system patches. To learn about the full capabilities of Systems Manager, see What Is Amazon EC2 Systems Manager?

Patch management is an important measure to prevent malware from infecting your systems. Most malware attacks look for vulnerabilities that are publicly known and in most cases are already patched by the maker of the operating system. These publicly known vulnerabilities are well documented and therefore easier for an attacker to exploit than having to discover a new vulnerability.

Patches for these new vulnerabilities are available through Systems Manager within hours after Microsoft releases them. There are two prerequisites to use Systems Manager to apply operating system patches. First, you must attach the IAM role you created in the previous section, EC2SSM, to your EC2 instance. Second, you must install the Systems Manager agent on your EC2 instance. If you have used a recent Microsoft Windows Server 2012 R2 AMI published by AWS, Amazon has already installed the Systems Manager agent on your EC2 instance. You can confirm this by logging in to an EC2 instance and looking for Amazon SSM Agent under Programs and Features in Windows. To install the Systems Manager agent on an instance that does not have the agent preinstalled or if you want to use the Systems Manager agent on your on-premises servers, see the documentation about installing the Systems Manager agent. If you forgot to attach the newly created role when launching your EC2 instance or if you want to attach the role to already running EC2 instances, see Attach an AWS IAM Role to an Existing Amazon EC2 Instance by Using the AWS CLI or use the AWS Management Console.

To make sure your EC2 instance receives operating system patches from Systems Manager, you will use the default patch baseline provided and maintained by AWS, and you will define a maintenance window so that you control when your EC2 instances should receive patches. For the maintenance window to be able to run any tasks, you also must create a new role for Systems Manager. This role is a different kind of role than the one you created earlier: Systems Manager will use this role instead of EC2. Earlier we created the EC2SSM role with the AmazonEC2RoleforSSM policy, which allowed the Systems Manager agent on our instance to communicate with the Systems Manager service. Here we need a new role with the policy AmazonSSMMaintenanceWindowRole to make sure the Systems Manager service is able to execute commands on our instance.

Create the Systems Manager IAM role

To create the new IAM role for Systems Manager, follow the same procedure as in the previous section, but in Step 3, choose the AmazonSSMMaintenanceWindowRole policy instead of the previously selected AmazonEC2RoleforSSM policy.

Screenshot of creating the new IAM role for Systems Manager

Finish the wizard and give your new role a recognizable name. For example, I named my role MaintenanceWindowRole.

Screenshot of finishing the wizard and giving your new role a recognizable name

By default, only EC2 instances can assume this new role. You must update the trust policy to enable Systems Manager to assume this role.

To update the trust policy associated with this new role:

  1. Navigate to the IAM console and choose Roles in the navigation pane.
  2. Choose MaintenanceWindowRole and choose the Trust relationships tab. Then choose Edit trust relationship.
  3. Update the policy document by copying the following policy and pasting it in the Policy Document box. As you can see, I have added the ssm.amazonaws.com service to the list of allowed Principals that can assume this role. Choose Update Trust Policy.
    {
       "Version":"2012-10-17",
       "Statement":[
          {
             "Sid":"",
             "Effect":"Allow",
             "Principal":{
                "Service":[
                   "ec2.amazonaws.com",
                   "ssm.amazonaws.com"
               ]
             },
             "Action":"sts:AssumeRole"
          }
       ]
    }

Associate a Systems Manager patch baseline with your instance

Next, you are going to associate a Systems Manager patch baseline with your EC2 instance. A patch baseline defines which patches Systems Manager should apply. You will use the default patch baseline that AWS manages and maintains. Before you can associate the patch baseline with your instance, though, you must determine if Systems Manager recognizes your EC2 instance.

Navigate to the EC2 console, scroll down to Systems Manager Shared Resources in the navigation pane, and choose Managed Instances. Your new EC2 instance should be available there. If your instance is missing from the list, verify the following:

  1. Go to the EC2 console and verify your instance is running.
  2. Select your instance and confirm you attached the Systems Manager IAM role, EC2SSM.
  3. Make sure that you deployed a NAT gateway in your public subnet to ensure your VPC reflects the diagram at the start of this post so that the Systems Manager agent can connect to the Systems Manager internet endpoint.
  4. Check the Systems Manager Agent logs for any errors.

Now that you have confirmed that Systems Manager can manage your EC2 instance, it is time to associate the AWS maintained patch baseline with your EC2 instance:

  1. Choose Patch Baselines under Systems Manager Services in the navigation pane of the EC2 console.
  2. Choose the default patch baseline as highlighted in the following screenshot, and choose Modify Patch Groups in the Actions drop-down.
    Screenshot of choosing Modify Patch Groups in the Actions drop-down
  3. In the Patch group box, enter the same value you entered under the Patch Group tag of your EC2 instance in “Step 1: Configure your EC2 instance.” In this example, the value I enter is Windows Servers. Choose the check mark icon next to the patch group and choose Close.Screenshot of modifying the patch group

Define a maintenance window

Now that you have successfully set up a role and have associated a patch baseline with your EC2 instance, you will define a maintenance window so that you can control when your EC2 instances should receive patches. By creating multiple maintenance windows and assigning them to different patch groups, you can make sure your EC2 instances do not all reboot at the same time. The Patch Group resource tag you defined earlier will determine to which patch group an instance belongs.

To define a maintenance window:

  1. Navigate to the EC2 console, scroll down to Systems Manager Shared Resources in the navigation pane, and choose Maintenance Windows. Choose Create a Maintenance Window.
    Screenshot of starting to create a maintenance window in the Systems Manager console
  2. Select the Cron schedule builder to define the schedule for the maintenance window. In the example in the following screenshot, the maintenance window will start every Saturday at 10:00 P.M. UTC.
  3. To specify when your maintenance window will end, specify the duration. In this example, the four-hour maintenance window will end on the following Sunday morning at 2:00 A.M. UTC (in other words, four hours after it started).
  4. Systems manager completes all tasks that are in process, even if the maintenance window ends. In my example, I am choosing to prevent new tasks from starting within one hour of the end of my maintenance window because I estimated my patch operations might take longer than one hour to complete. Confirm the creation of the maintenance window by choosing Create maintenance window.
    Screenshot of completing all boxes in the maintenance window creation process
  5. After creating the maintenance window, you must register the EC2 instance to the maintenance window so that Systems Manager knows which EC2 instance it should patch in this maintenance window. To do so, choose Register new targets on the Targets tab of your newly created maintenance window. You can register your targets by using the same Patch Group tag you used before to associate the EC2 instance with the AWS-provided patch baseline.
    Screenshot of registering new targets
  6. Assign a task to the maintenance window that will install the operating system patches on your EC2 instance:
    1. Open Maintenance Windows in the EC2 console, select your previously created maintenance window, choose the Tasks tab, and choose Register run command task from the Register new task drop-down.
    2. Choose the AWS-RunPatchBaseline document from the list of available documents.
    3. For Parameters:
      1. For Role, choose the role you created previously (called MaintenanceWindowRole).
      2. For Execute on, specify how many EC2 instances Systems Manager should patch at the same time. If you have a large number of EC2 instances and want to patch all EC2 instances within the defined time, make sure this number is not too low. For example, if you have 1,000 EC2 instances, a maintenance window of 4 hours, and 2 hours’ time for patching, make this number at least 500.
      3. For Stop after, specify after how many errors Systems Manager should stop.
      4. For Operation, choose Install to make sure to install the patches.
        Screenshot of stipulating maintenance window parameters

Now, you must wait for the maintenance window to run at least once according to the schedule you defined earlier. Note that if you don’t want to wait, you can adjust the schedule to run sooner by choosing Edit maintenance window on the Maintenance Windows page of Systems Manager. If your maintenance window has expired, you can check the status of any maintenance tasks Systems Manager has performed on the Maintenance Windows page of Systems Manager and select your maintenance window.

Screenshot of the maintenance window successfully created

Monitor patch compliance

You also can see the overall patch compliance of all EC2 instances that are part of defined patch groups by choosing Patch Compliance under Systems Manager Services in the navigation pane of the EC2 console. You can filter by Patch Group to see how many EC2 instances within the selected patch group are up to date, how many EC2 instances are missing updates, and how many EC2 instances are in an error state.

Screenshot of monitoring patch compliance

In this section, you have set everything up for patch management on your instance. Now you know how to patch your EC2 instance in a controlled manner and how to check if your EC2 instance is compliant with the patch baseline you have defined. Of course, I recommend that you apply these steps to all EC2 instances you manage.

Summary

In Part 1 of this blog post, I have shown how to configure EC2 instances for use with Systems Manager, EBS Snapshot Scheduler, and Amazon Inspector. I also have shown how to use Systems Manager to keep your Microsoft Windows–based EC2 instances up to date. In Part 2 of this blog post tomorrow, I will show how to take regular snapshots of your data by using EBS Snapshot Scheduler and how to use Amazon Inspector to check if your EC2 instances running Microsoft Windows contain any CVEs.

If you have comments about this post, submit them in the “Comments” section below. If you have questions about or issues implementing this solution, start a new thread on the EC2 forum or the Amazon Inspector forum, or contact AWS Support.

– Koen