Trailing EOL causes `awscc_ec2_verified_access_group` policy to change at every apply

[nnsense]

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Terraform CLI and Terraform AWS Cloud Control Provider Version

Terraform v1.6.3
on linux_amd64
+ provider registry.terraform.io/hashicorp/aws v5.25.0
+ provider registry.terraform.io/hashicorp/awscc v0.64.0

Affected Resource(s)

• awscc_ec2_verified_access_group

Terraform Configuration Files

The following (working) configuration shows the group policy to be different at every apply

resource "awscc_ec2_verified_access_trust_provider" "main" {
  policy_reference_name           = "iam_sso2"
  trust_provider_type             = "user"
  user_trust_provider_type        = "iam-identity-center"
}

resource "awscc_ec2_verified_access_instance" "main" {
  verified_access_trust_provider_ids = [awscc_ec2_verified_access_trust_provider.main.verified_access_trust_provider_id]
}

resource "awscc_ec2_verified_access_group" "main" {
  verified_access_instance_id = awscc_ec2_verified_access_instance.main.id

  policy_enabled  = true
  policy_document = <<-EOT
    // grant access to domain email users
    permit(principal,action,resource)
    when {
        context.iam_sso2.user.email.address like "*@domain.com"
    };
  EOT
}

It does the same if I use a single line with \n :

policy_document = "// grant access to domain email users\npermit(principal,action,resource)\nwhen {\n    context.iam_sso2.user.email.address like \"*@domain.com\"\n};\n"

but, if I remove the trailing new line

policy_document = "// grant access to domain email users\npermit(principal,action,resource)\nwhen {\n    context.iam_sso2.user.email.address like \"*@domain.com\"\n};"

the configuration is applied every time without changes.

The same works with HEREDOC, adding chomp to remove the trailing new line:

resource "awscc_ec2_verified_access_trust_provider" "main" {
  policy_reference_name           = "iam_sso2"
  trust_provider_type             = "user"
  user_trust_provider_type        = "iam-identity-center"
}

resource "awscc_ec2_verified_access_instance" "main" {
  verified_access_trust_provider_ids = [awscc_ec2_verified_access_trust_provider.main.verified_access_trust_provider_id]
}

resource "awscc_ec2_verified_access_group" "main" {
  verified_access_instance_id = awscc_ec2_verified_access_instance.main.id

  policy_enabled  = true
  policy_document = chomp(<<-EOT
    // grant access to domain email users
    permit(principal,action,resource)
    when {
        context.iam_sso2.user.email.address like "*@domain.com"
    };
  EOT
  )
}

Expected Behavior

The policy should apply without having to get rid of the new line. Knowing it, it's easy to fix (just remove the last \n on single line or use chomp with heredocs), but I had hard time figuring out that the issue was the trailing new line, not the heredoc, or multi-line, or the comment.

Steps to Reproduce

Just apply the example config above: the top one causes terraform to find the policy as "changed" at every apply, the last one is working every time without showing any changes (beside the real ones, if any).

[kadrach]

I suspect this is similar to #1284, where the VerifiedPermissions APIs do not return your exact input policy (string) but rather a modified version of it.