data "aws_ecs_task_definition" "mongo" {
  task_definition = aws_ecs_task_definition.mongo.family
}

resource "aws_ecs_cluster" "foo" {
  name = "foo"
}

resource "aws_ecs_service" "mongo" {
  cluster = aws_ecs_cluster.foo.id
  desired_count = 2
  name = "mongo"
  task_definition = data.aws_ecs_task_definition.mongo.arn
}

resource "aws_ecs_task_definition" "mongo" {
  container_definitions = <<-EOF
    [
     {
     "cpu": 128,
     "environment": [{
     "name": "SECRET",
     "value": "KEY"
     }],
     "essential": true,
     "image": "mongo:latest",
     "memory": 128,
     "memoryReservation": 64,
     "name": "mongodb"
     }
    ]
    
  EOF
  family = "mongodb"
}