Day 8: ECS Task Definitions: Defining Your Containers

This content originally appeared on DEV Community and was authored by Pragnesh Patel

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.

This content originally appeared on DEV Community and was authored by Pragnesh Patel