data-source/aws_iam_role: Add permissions_boundary attribute

[bflad]

Reference: #5174

Changes proposed in this pull request:

• Add permissions boundary support to aws_iam_role data source
• Minor refactoring for newer practices

Output from acceptance testing: AWS Commercial

$ make testacc TEST=./aws TESTARGS='-run=TestAccAWSDataSourceIAMRole_basic'
==> Checking that code complies with gofmt requirements...
TF_ACC=1 go test ./aws -v -run=TestAccAWSDataSourceIAMRole_basic -timeout 120m
=== RUN   TestAccAWSDataSourceIAMRole_basic
--- PASS: TestAccAWSDataSourceIAMRole_basic (10.81s)
PASS
ok  	github.com/terraform-providers/terraform-provider-aws/aws	10.867s

Output from acceptance testing: AWS GovCloud (US)

$ make testacc TEST=./aws TESTARGS='-run=TestAccAWSDataSourceIAMRole_basic'
==> Checking that code complies with gofmt requirements...
TF_ACC=1 go test ./aws -v -run=TestAccAWSDataSourceIAMRole_basic -timeout 120m
=== RUN   TestAccAWSDataSourceIAMRole_basic
--- PASS: TestAccAWSDataSourceIAMRole_basic (19.94s)
PASS
ok  	github.com/terraform-providers/terraform-provider-aws/aws	19.994s

[mbfrahry]

LGTM with a minor comment

[mbfrahry]

Do we have to set this to an empty string? I would think that Terraform would automatically do this but maybe I'm wrong.

[bflad]

Since the d.Set() is wrapped in a conditional, this is to properly handle the missing attribute if its not sent back by the API (output.Role.PermissionsBoundary is nil). Otherwise Terraform will throw an error about the missing attribute in this scenario:

output "permissions_boundary" {
  value = "${data.aws_iam_role.example.permissions_boundary}"
}

It can potentially go away after Terraform 0.12 allows returning full resources.

[bflad]

This has been released in version 1.29.0 of the AWS provider. Please see the Terraform documentation on provider versioning or reach out if you need any assistance upgrading.

[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!