aws

Amazon ECS is a highly scalable, fast, container management service that makes it easy to run, stop, and manage Docker containers on a cluster of EC2 instances.

An ECS Container Instance is an EC2 instance that is running the ECS container agent, and has been registered into an ECS cluster.

Create an Instance Profile

First we need to create an instance profile for the instance.

And before that, setup the roles for the profile.

Create a role for the profile

Create two role policy files.

The first I named ecs-policy.json:

{
  "Version": "2016-07-13",
  "Statement": [
    {
      "Effect": "Allow",
      "Principal": {
        "Service": "ec2.amazonaws.com"
      },
      "Action": "sts:AssumeRole"
    }
  ]
}

The second I named role-policy.json:

{
  "Version": "2016-07-13",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": [
        "ecr:BatchCheckLayerAvailability",
        "ecr:BatchGetImage",
        "ecr:DescribeRepositories",
        "ecr:GetAuthorizationToken",
        "ecr:GetDownloadUrlForLayer",
        "ecr:GetRepositoryPolicy",
        "ecr:ListImages",
        "ecs:CreateCluster",
        "ecs:DeregisterContainerInstance",
        "ecs:DiscoverPollEndpoint",
        "ecs:Poll",
        "ecs:RegisterContainerInstance",
        "ecs:StartTask",
        "ecs:StartTelemetrySession",
        "ecs:SubmitContainerStateChange",
        "ecs:SubmitTaskStateChange"
      ],
      "Resource": [
        "*"
      ]
    }
  ]
}

Create a role with the two policies:

aws iam create-role --role-name ecsRole --assume-role-policy-document file://ecs-policy.json
aws iam put-role-policy --role-name ecsRole --policy-name ecsRolePolicy  --policy-document file://role-policy.json

Create the instance profile

Finally, create the instance profile with the new role:

aws iam create-instance-profile --instance-profile-name webserver
aws iam add-role-to-instance-profile --instance-profile-name webserver --role-name ecsRole

Launch an EC2 Instance

Create a security group for the Instance

Open ports 22 and 80:

aws ec2 create-security-group --group-name MySecurityGroup
aws ec2 authorize-security-group-ingress --group-name MySecurityGroup --protocol tcp --port 22 --cidr 0.0.0.0/0
aws ec2 authorize-security-group-ingress --group-name MySecurityGroup --protocol tcp --port 80 --cidr 0.0.0.0/0

Note the security group id, which is needed when launching an EC2 instance.

Launch an instance

We’ll be launching an EC2 instance in an ECS cluster.

Create an ECS cluster:

aws ecs create-cluster --cluster-name my-cluster

Create a userdata.txt (this gets run when the instance is created):

#!/bin/bash
echo 'ECS_CLUSTER=my-cluster' >> /etc/ecs/ecs.config

Launch an instance inside the cluster:

aws ec2 run-instances --count 1 --image-id ami-0bf2da68 --instance-type t2.micro --key-name aws-beau-sydney --iam-instance-profile Name= webserver --security-group-id sg-xxxxxx --associate-public-ip-address --user-data file://userdata.txt

Now you can run tasks and services on the instance.

Start a container

Register a task

Describe your task in a Task Definition file, which I named ecs-task.json:

{
  "family": "web-app",
  "containerDefinitions": [
    {
      "image": "project/web-app:latest",
      "name": "web-app",
      "memory": 10,
      "cpu": 10,
      "portMappings": [
        {
          "containerPort": 80,
          "hostPort": 80
        }
      ],
      "essential": true
    }
  ]
}

Register it:

aws ecs register-task-definition --cli-input-json file://ecs-task.json

List tasks:

aws ecs list-tasks --cluster my-cluster

Run the task

aws ecs run-task --cluster my-cluster --count 1 --task-definition web-app:1

To deregister a task:

aws ecs deregister-task-definition --task-definition web-app:1