Better errors when resources don't get created due to invalid JSON

[ghost]

This issue was originally opened by @mzhaase as hashicorp/terraform#18429. It was migrated here as a result of the provider split. The original body of the issue is below.

---

Terraform Version

Terraform v0.11.7
+ provider.aws v1.26.0
+ provider.cloudflare v1.0.0
+ provider.template v1.0.0

resource "aws_ecs_task_definition" "definition" {
  family                         = "abc"
  container_definitions =<<EOF
  [
    {
     "name": "abc",
     "image": "busybox:latest",
     "essential": true,
     "portMappings": [
       {
         "containerPort": 25,
         "hostPort": 25
       }
     ]
     }, # <-- invalid comma
    }
  ]
EOF
}

resource "aws_ecs_service" "service" {
  name                = "abc"
  cluster             = "my-cluster"
  task_definition     = "${aws_ecs_task_definition.definition.arn}"
  scheduling_strategy = "DAEMON"
}

Expected Behavior

aws_ecs_task_definition.definition.container_definitions: invalid JSON

Actual Behavior

aws_ecs_service.service: Resource 'aws_ecs_task_definition.definition' not found for variable 'aws_ecs_task_definition.definition.arn'

Steps to Reproduce

1. try to apply above code

[bflad]

Hi @mzhaase 👋 Sorry for the unexpected behavior here and that this issue got bounced over to the AWS provider (usually this is correct, but I happen have seen this particular issue before 😄 )

It turns out this is likely an issue upstream in Terraform core, rather than anything to do with the AWS provider specifically. This scenario basically occurs anytime we implement a resource attribute with a ValidateFunc and then that resource is then referenced by another resource. Terraform core, when the first resource is failing that validation, is preferring to return the invalid resource reference message instead of the resource validation error.

I'm going to close this issue out as we have a few upstream tracking issues relating to this:

• Resource missing errors propagating over validation errors during plan terraform#18129
• Misleading error message when JSON parsing fails terraform#16332
• Confusing downstream error on reliant resources when an upstream resource is invalid. terraform#14333

I would suggest commenting on and upvoting those for the latest updates on this. 👍

[mzhaase]

@bflad will do, thanks.

[ghost]

I'm going to lock this issue because it has been closed for 30 days ⏳. This helps our maintainers find and focus on the active issues.

If you feel this issue should be reopened, we encourage creating a new issue linking back to this one for added context. Thanks!