Applying tags to S3 bucket tries to remove system (aws:*) tags

[dave2]

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Terraform Version

$ terraform -v
Terraform v0.11.10

Note: I have checked the actual code path in github so it should still be affecting terraform even tho I am not on the latest version.

Affected Resource(s)

• aws_s3_bucket

Terraform Configuration Files

resource "aws_s3_bucket" "example" {
  bucket = "example"
  tags = {
    "some:tag" = "some:value"
  }
}

Debug Output

* aws_s3_bucket.example: "example": InvalidTag: System Tags cannot be removed  by requester

I've included only the error message as the rest of the output is correct (it builds the list of tags provided in the terraform template, and feeds those to the correct API).

Expected Behavior

Bucket has existing aws:* prefix tags due to being created by CloudFormation. These must be preserved over tag updates, because we cannot remove/edit them.

Although the AWS API documentation describes PUT Bucket Tagging as "add tags" this is incorrect, the tag set must be the complete set of tags on the bucket including reserved ones, as any tag not present in the list is implied delete.

API doc is here: https://docs.aws.amazon.com/AmazonS3/latest/API/RESTBucketPUTtagging.html

I've confirmed with AWS that the doc is indeed wrong, and you have to provide existing tags to keep them.

Actual Behavior

Reserved tags are filtered from the incoming list, but not preserved on the update, causing the resource to fail to be updated.

Steps to Reproduce

1. Create a bucket with CloudFormation
2. Import the bucket to a terraform resource
3. Apply any number of tags incl. zero, this will fault with the message in Debug above.

Important Factoids

Nothing magical!

References

AWS API documentation (that is incorrect anyway!): https://docs.aws.amazon.com/AmazonS3/latest/API/RESTBucketPUTtagging.html

[dave2]

Note that around L23 in aws/s3_tags.go there are explicit delete and create paths. But the API actually doesn't work this way, and instead you should do read-modify-write on the bucket tags.

https://github.com/terraform-providers/terraform-provider-aws/blob/master/aws/s3_tags.go#L23

[ewbankkit]

@dave2 Interestingly, you don't get this error if there are also tags to be deleted, in which case https://docs.aws.amazon.com/AmazonS3/latest/API/RESTBucketDELETEtagging.html is called first and the system tags are deleted by this call. The subsequent call to https://docs.aws.amazon.com/AmazonS3/latest/API/RESTBucketPUTtagging.html then succeeds but of course the system tags are now lost.
The correct solution is to include any system tags that Terraform ignores when setting S3 bucket tags.

[ghost]

This has been released in version 2.27.0 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!