Day 8: ECS Task Definitions: Defining Your Containers

Building on Day 7, today: Task definitions—the blueprint for containers.

Key Parameters

• Container definitions: Image, ports, CPU/memory.
• Volumes, networking, etc.

Step 1: Create Task Definition

JSON example for our app:

{
  "family": "my-task",
  "containerDefinitions": [
    {
      "name": "my-container",
      "image": "<account-id>.dkr.ecr.us-west-2.amazonaws.com/my-app-repo:latest",
      "cpu": 256,
      "memory": 512,
      "portMappings": [{ "containerPort": 3000, "hostPort": 3000 }],
      "essential": true
    }
  ],
  "requiresCompatibilities": ["FARGATE"],
  "networkMode": "awsvpc",
  "cpu": "256",
  "memory": "512"
}

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

Step 2: Run a Task

Console: ECS > Clusters > my-cluster > Tasks > Run new task > Select definition.

CLI:

aws ecs run-task --cluster my-cluster --task-definition my-task --launch-type FARGATE --network-configuration "awsvpcConfiguration={subnets=[subnet-id],securityGroups=[sg-id],assignPublicIp=ENABLED}"

Check logs in console.

Today’s Takeaway

Tasks defined and running!

What’s Next?
In Day 9, we’ll deploy ECS services.