Tutorial: Creating a Cluster with a Fargate Task Using the Amazon ECS CLI - Amazon Elastic Container Service

Tutorial: Creating a Cluster with a Fargate Task Using the Amazon ECS CLI

This tutorial shows you how to set up a cluster and deploy a service with tasks using the Fargate launch type.

Prerequisites

Complete the following prerequisites:

Step 1: Create the Task Execution IAM Role

The Amazon ECS container agent makes calls to AWS APIs on your behalf, so it requires an IAM policy and role for the service to know that the agent belongs to you. This IAM role is referred to as a task execution IAM role. If you already have a task execution role created to use, you can skip this step. For more information, see Amazon ECS Task Execution IAM Role.

To create the task execution IAM role using the AWS CLI

  1. Create a file named task-execution-assume-role.json with the following contents:

    { "Version": "2012-10-17", "Statement": [ { "Sid": "", "Effect": "Allow", "Principal": { "Service": "ecs-tasks.amazonaws.com" }, "Action": "sts:AssumeRole" } ] }
  2. Create the task execution role:

    aws iam --region us-west-2 create-role --role-name ecsTaskExecutionRole --assume-role-policy-document file://task-execution-assume-role.json
  3. Attach the task execution role policy:

    aws iam --region us-west-2 attach-role-policy --role-name ecsTaskExecutionRole --policy-arn arn:aws:iam::aws:policy/service-role/AmazonECSTaskExecutionRolePolicy

Step 2: Configure the Amazon ECS CLI

The Amazon ECS CLI requires credentials in order to make API requests on your behalf. It can pull credentials from environment variables, an AWS profile, or an Amazon ECS profile. For more information, see Configuring the Amazon ECS CLI.

To create an Amazon ECS CLI configuration

  1. Create a cluster configuration, which defines the AWS region to use, resource creation prefixes, and the cluster name to use with the Amazon ECS CLI:

    ecs-cli configure --cluster tutorial --default-launch-type FARGATE --config-name tutorial --region us-west-2
  2. Create a CLI profile using your access key and secret key:

    ecs-cli configure profile --access-key AWS_ACCESS_KEY_ID --secret-key AWS_SECRET_ACCESS_KEY --profile-name tutorial-profile

Step 3: Create a Cluster and Configure the Security Group

To create an ECS cluster and security group

  1. Create an Amazon ECS cluster with the ecs-cli up command. Because you specified Fargate as your default launch type in the cluster configuration, this command creates an empty cluster and a VPC configured with two public subnets.

    ecs-cli up --cluster-config tutorial --ecs-profile tutorial-profile

    This command may take a few minutes to complete as your resources are created. The output of this command contains the VPC and subnet IDs that are created. Take note of these IDs as they are used later.

  2. Using the AWS CLI, retrieve the default security group ID for the VPC. Use the VPC ID from the previous output:

    aws ec2 describe-security-groups --filters Name=vpc-id,Values=VPC_ID --region us-west-2

    The output of this command contains your security group ID, which is used in the next step.

  3. Using AWS CLI, add a security group rule to allow inbound access on port 80:

    aws ec2 authorize-security-group-ingress --group-id security_group_id --protocol tcp --port 80 --cidr 0.0.0.0/0 --region us-west-2

Step 4: Create a Compose File

For this step, create a simple Docker compose file that creates a simple PHP web application. At this time, the Amazon ECS CLI supports Docker compose file syntax versions 1, 2, and 3. This tutorial uses Docker compose v3.

Here is the compose file, which you can name docker-compose.yml. The web container exposes port 80 for inbound traffic to the web server. It also configures container logs to go to the CloudWatch log group created earlier. This is the recommended best practice for Fargate tasks.

version: '3' services: web: image: amazon/amazon-ecs-sample ports: - "80:80" logging: driver: awslogs options: awslogs-group: tutorial awslogs-region: us-west-2 awslogs-stream-prefix: web
Note

If your account already contains a CloudWatch Logs log group named tutorial in the us-west-2 Region, choose a unique name so the ECS CLI creates a new log group for this tutorial.

In addition to the Docker compose information, there are some parameters specific to Amazon ECS that you must specify for the service. Using the VPC, subnet, and security group IDs from the previous step, create a file named ecs-params.yml with the following content:

version: 1 task_definition: task_execution_role: ecsTaskExecutionRole ecs_network_mode: awsvpc task_size: mem_limit: 0.5GB cpu_limit: 256 run_params: network_configuration: awsvpc_configuration: subnets: - "subnet ID 1" - "subnet ID 2" security_groups: - "security group ID" assign_public_ip: ENABLED

Step 5: Deploy the Compose File to a Cluster

After you create the compose file, you can deploy it to your cluster with ecs-cli compose service up. By default, the command looks for files called docker-compose.yml and ecs-params.yml in the current directory; you can specify a different docker compose file with the --file option, and a different ECS Params file with the --ecs-params option. By default, the resources created by this command have the current directory in their titles, but you can override that with the --project-name option. The --create-log-groups option creates the CloudWatch log groups for the container logs.

ecs-cli compose --project-name tutorial service up --create-log-groups --cluster-config tutorial --ecs-profile tutorial-profile

Step 6: View the Running Containers on a Cluster

After you deploy the compose file, you can view the containers that are running in the service with ecs-cli compose service ps.

ecs-cli compose --project-name tutorial service ps --cluster-config tutorial --ecs-profile tutorial-profile

Output:

Name                                           State    Ports                     TaskDefinition  Health
tutorial/0c2862e6e39e4eff92ca3e4f843c5b9a/web  RUNNING  34.222.202.55:80->80/tcp  tutorial:1      UNKNOWN

In the above example, you can see the web container from your compose file, and also the IP address and port of the web server. If you point your web browser at that address, you should see the PHP web application. Also in the output is the task-id value for the container. Copy the task ID as you use it in the next step.

Step 7: View the Container Logs

View the logs for the task:

ecs-cli logs --task-id 0c2862e6e39e4eff92ca3e4f843c5b9a --follow --cluster-config tutorial --ecs-profile tutorial-profile
Note

The --follow option tells the Amazon ECS CLI to continuously poll for logs.

Step 8: Scale the Tasks on the Cluster

You can scale up your task count to increase the number of instances of your application with ecs-cli compose service scale. In this example, the running count of the application is increased to two.

ecs-cli compose --project-name tutorial service scale 2 --cluster-config tutorial --ecs-profile tutorial-profile

Now you should see two more containers in your cluster:

ecs-cli compose --project-name tutorial service ps --cluster-config tutorial --ecs-profile tutorial-profile

Output:

Name                                           State    Ports                      TaskDefinition  Health
tutorial/0c2862e6e39e4eff92ca3e4f843c5b9a/web  RUNNING  34.222.202.55:80->80/tcp   tutorial:1      UNKNOWN
tutorial/d9fbbc931d2e47ae928fcf433041648f/web  RUNNING  34.220.230.191:80->80/tcp  tutorial:1      UNKNOWN

Step 9: View your Web Application

Enter the IP address for the task in your web browser and you should see a webpage that displays the Simple PHP App web application.

Step 10: Clean Up

When you are done with this tutorial, you should clean up your resources so they do not incur any more charges. First, delete the service so that it stops the existing containers and does not try to run any more tasks.

ecs-cli compose --project-name tutorial service down --cluster-config tutorial --ecs-profile tutorial-profile

Now, take down your cluster, which cleans up the resources that you created earlier with ecs-cli up.

ecs-cli down --force --cluster-config tutorial --ecs-profile tutorial-profile