Terraform unquoted resource for Terraform 0.11

Question

I am using terraform 0.11 for a custom module implementation of terraform-aws-provider. Inside the module there are a lot of unquoted resource value assignments that make me confused since they are not working.

This is the sample module code that I am using

resource "aws_iam_policy" "example" {
  name   = example_policy
  policy = data.aws_iam_policy_document.example.json
}

In the official terraform documentation, it was given with interpolation around the value to become

resource "aws_iam_policy" "example" {
  name   = "example_policy"
  policy = "${data.aws_iam_policy_document.example.json}"
}

from: https://www.terraform.io/docs/providers/aws/d/iam_policy_document.html

When I tried to do terraform get the following error message came up: Unknown token: 39:24 IDENT data.aws_iam_policy_document.example.json, and when I tried to use terraform 0.12, it managed to fetch it correctly.

Is this unquoted resource value exclusive to terraform > v0.12?

supersam654 supersam654 · Accepted Answer · 2019-09-07T16:56:35

Yes. Terraform 0.11 requires that all references look like string interpolations (like your second example). Terraform 0.12 added support for first-class expressions which let you reference variables outside of strings (like your first example).

The docs also include an example of the newer, cleaner syntax:

# Old 0.11 example
tags = "${merge(map("Name", "example"), var.common_tags)}"

# Updated 0.12 example
tags = merge({ Name = "example" }, var.common_tags)

Terraform unquoted resource for Terraform 0.11

1 Answers