Btukfyl

In terraform I am attempting to pass a variable (list) to a module that we built. This variable needs to be used within a aws_ecs_task_definition resource in the container_definitions.

Right now I am just starting with an empty default list defined as a variable:

variable "task_enviornment" {

  type        = "list"

  default = 

}

My ECS task definition looks like this:

resource "aws_ecs_task_definition" "ecs_task_definition" {

  family                   = "${var.ecs_family}"

  network_mode             = "awsvpc"

  task_role_arn            = "${aws_iam_role.iam_role.arn}"

  execution_role_arn       = "${data.aws_iam_role.iam_ecs_task_execution_role.arn}"

  requires_compatibilities = ["FARGATE"]

  cpu                      = "${var.fargate_cpu}"

  memory                   = "${var.fargate_memory}"



  container_definitions =<<DEFINITION

  [

    {

      "cpu": ${var.fargate_cpu},

      "image": "${var.app_image}",

      "memory": ${var.fargate_memory},

      "name": "OURNAME",

      "networkMode": "awsvpc",

      "environment": "${jsonencode(var.task_enviornment)}",

      "logConfiguration": {

        "logDriver": "awslogs",

        "options": {

          "awslogs-group" : "${aws_cloudwatch_log_group.fargate-logs.name}",

          "awslogs-region": "us-east-1",

          "awslogs-stream-prefix": "demo"

        }

      },

      "portMappings": [

        {

        "containerPort": ${var.app_port},

        "hostPort": ${var.app_port}

        }

      ]

    }

  ]

  DEFINITION

}

The part I am having a problem with with the "environment" part:

"environment": "${jsonencode(var.task_enviornment)}",

I have tried a few different ways to get this to work.

If I do "environment": "${jsonencode(var.task_enviornment)}",
I get ECS Task Definition container_definitions is invalid: Error decoding JSON: json: cannot unmarshal string into Go struct field ContainerDefinition.Environment of type *ecs.KeyValuePair

If I do "environment": "${var.task_enviornment}", or "environment": ["${var.task_enviornment}"],

I get At column 1, line 1: output of an HIL expression must be a string, or a single list (argument 8 is TypeList) in:
Then it just outputs the contents of container_definitions

I did also try adding default values and I was getting similar error messages. However I do need to be able to handle no values being sent in, so an empty list.

variable "task_enviornment" {

  type        = "list"

  default = [

    {

      "name" = "BUCKET",

      "value" = "test"

    }

  ]

}

After a lot of investigation and a fresh set of eyes looking at this figured out the solution. I am unsure why this fixes it, and I feel like this is likely a bug.

Needed to do 2 things to fix this.

1. 
   

   Remove type = "list" from the variable definition.

   
   
   

   variable "task_environment" {
default =
}

   
   



2. Remove the quotes when using the variable:
   "environment": ${jsonencode(var.task_environment)},