aws_efs_mount_target dns_name attribute returns aws_efs_filesystem dns_name instead

[ghost]

This issue was originally opened by @pll as hashicorp/terraform#25157. It was migrated here as a result of the provider split. The original body of the issue is below.

---

Terraform Version

$ terraform -v
Terraform v0.12.26
+ provider.aws v2.65.0

Terraform Configuration Files

resource "aws_efs_file_system" "fs" {
  creation_token = "my-product"
}

output "efs-file-system-dns-name" {
  value = aws_efs_file_system.fs.dns_name
}

resource "aws_efs_mount_target" "fs" {
  count		  = length(local.pri_subnet_ids)
  file_system_id  = aws_efs_file_system.fs.id
  subnet_id	  = element(local.pri_subnet_ids, count.index)
  security_groups = [ element(aws_security_group.efs.*.id, count.index) ]
}

output "efs-mount-target-dns-name" {
  value = aws_efs_mount_target.fs.*.dns_name
}

outputs:

efs-file-system-dns-name = [
  "fs-f263e871.efs.us-east-1.amazonaws.com",
]

efs-mount-target-dns-name = [
  "fs-f263e871.efs.us-east-1.amazonaws.com",
  "fs-f263e871.efs.us-east-1.amazonaws.com",
  "fs-f263e871.efs.us-east-1.amazonaws.com",
]

Expected Behavior

Expected aws_efs_mount_target.dns_name to be of the form availability-zone.file-system-id.efs.aws-region.amazonaws.com as per the AWS EFS documentation:

https://docs.aws.amazon.com/efs/latest/ug/mounting-fs-mount-cmd-dns-name.html

Actual Behavior

Got the aws_efs_filesystem.dns_name of the form file-system-id.efs.aws-region.amazonaws.com instead, which defeats the entire purpose of creating per-AZ EFS Mount Targets.

Steps to Reproduce

1. Create an EFS volume and mount targets as described by the code above.
2. terraform init
3. terraform apply

[ewbankkit]

https://github.com/terraform-providers/terraform-provider-aws/blob/d15a5fede10ae10b22813862263b89a02a6934cd/aws/resource_aws_efs_mount_target.go#L217-L223

which is the same as the EFS file system DNS name:

https://github.com/terraform-providers/terraform-provider-aws/blob/d15a5fede10ae10b22813862263b89a02a6934cd/aws/resource_aws_efs_file_system.go#L320

Related:

• provider/aws: Updating the aws_efs_mount_target dns_name terraform#11023
• AWS announcement

@pll Thanks for raising this issue. Can you use the file system DNS name or do you explicitly require the per-AZ DNS name?

[pll]

Hi @ewbankkit,

I really wanted to use the per-AZ DNS name to isolate where my EFS volumes are accessed from, and by what. But yeah, I can make do with just the filesystem DNS name for now.

Thanks for jumping on this so quickly!

[DrFaust92]

I've addressed this in #13650 (with some other minor changes)

[pll]

@DrFaust92 - Awesome! Thanks for such a quick turn-around!

[bflad]

Support for new mount_target_dns_name attributes on the resource and data source has been merged and will release with version 2.67.0 of the Terraform AWS Provider, likely tomorrow. 👍 Thanks to @DrFaust92 for the implementation.

[pll]

@bflad & @DrFaust92 - Awesome! Thank you so much for the quick turn-around on this. I'll be sure to give it a try tomorrow, or as soon as 2.67.0 is released!

[ghost]

This has been released in version 2.67.0 of the Terraform AWS provider. Please see the Terraform documentation on provider versioning or reach out if you need any assistance upgrading.

For further feature requests or bug reports with this functionality, please create a new GitHub issue following the template for triage. 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!