Let's say you have the following files on your Terraform server.

├── required_providers.tf
├── elastic_container_services (directory)
│   ├── task_defintions (directory)
│   ├── ├── fargate (directory)
│   ├── ├── ├── provider.tf
│   ├── ├── ├── task_definition.tf

required_providers.tf will almost always have this.

terraform {
  required_providers {
    aws = {
      source  = "hashicorp/aws"
    }
  }
}

Let's say provider.tf has the following. In this example, the "default" profile in /home/username/.aws/config and /home/username/.aws/credentials is being used. This assumes you have setup Terraform as described in Amazon Web Services (AWS) - Getting Started with Terraform.

provider "aws" {
  alias   = "default"
  profile = "default"
  region  = "default"
}

This assumes you have already Created an Elastic Container Service (ECS) Cluster using Terraform.

An ECS deployment can be:

• EC2 - apps run in EC2 instance
• FARGATE - serverless (no EC2 instances)

task_definitions.tf could have something like this where requires_compatibilities is FARGATE.

resource "aws_ecs_task_definition" "flask-fargate-task-definition" {
  family                   = "flask"
  network_mode             = "awsvpc"
  requires_compatibilities = ["FARGATE"]
  cpu                      = 1024
  memory                   = 2048

  container_definitions = jsonencode([
    {
      name = "flask-container"
      cpu       = 10
      memory    = 512
      image: "tiangolo/uwsgi-nginx-flask:python3.11",
      portMappings: [
        {
          containerPort: 3000,
          hostPort: 3000
        }
      ]
    }
  ])
}

You may need to reissue the terraform init command.

~]# terraform init
Initializing the backend...
Initializing modules...
Initializing provider plugins...
Terraform has been successfully initialized!

The terraform plan command can be used to see what Terraform will try to do.

~]$ terraform plan
Terraform will perform the following actions:

  # aws_ecs_task_definition.flask-fargate-task-definition will be created
  + resource "aws_ecs_task_definition" "flask-fargate-task-definition" {
      + arn                      = (known after apply)
      + arn_without_revision     = (known after apply)
      + container_definitions    = jsonencode(
            [
              + {
                  + cpu          = 10
                  + image        = "tiangolo/uwsgi-nginx-flask:python3.11"
                  + memory       = 512
                  + name         = "flask"
                  + portMappings = [
                      + {
                          + containerPort = 80
                          + hostPort      = 80
                        },
                    ]
                },
            ]
        )
      + cpu                      = "1024"
      + family                   = "flask"
      + id                       = (known after apply)
      + memory                   = "2048"
      + network_mode             = "awsvpc"
      + requires_compatibilities = [
          + "EC2",
        ]
      + revision                 = (known after apply)
      + skip_destroy             = false
      + tags_all                 = (known after apply)
    }

Plan: 1 to add, 0 to change, 0 to destroy.

The terraform apply command can be used to create, update or delete the resource.

terraform apply -auto-approve

The aws ecs list-task-definitions command can be used to list the ECS Task Definitions that have been created. Something like this should be returned.

~]$ aws ecs list-task-definitions
{
    "taskDefinitionArns": [
        "arn:aws:ecs:us-east-1:123456789012:task-definition/my-task-definition:1",
        "arn:aws:ecs:us-east-1:123456789012:task-definition/my-task-definition:2"
    ]
}

And the Task Definition should be listed in the AWS ECS console.