Provider cannot use variables from resources

[janschumann]

It would be great, metadata of an atlas artifact could be used in provider configuration. Please see the following example:

resource "atlas_artifact" "debian7-puppet4-base" {
  name    = "janschumann/debian7-puppet4-base"
  type    = "aws.ami"
  version = "latest"
}

provider "aws" {
  region = "${atlas_artifact.debian7-puppet4-base-eu.metadata_full.region}"
}

resource "aws_instance" "debian7-puppet4-base" {
  ami           = "${atlas_artifact.debian7-puppet4-base.metadata_full.ami_id}"
  instance_type = "t2.medium"
}

The provider seems to be interpreted first and thus, atlas_artifact.debian7-puppet4-base-eu.metadata_full.region is empty.

What do you think?

[apparentlymart]

I think what you're describing here is the issue I wrote up in #2976. I very much agree that the current behavior is sub-optimal and it should be possible to do what you showed in your example, though as you'll see in that other issue there are some non-trivial architectural issues to work through before that can be fully supported.

There is currently a (rather awkward) workaround for this that may allow you to proceed: once the atlas_artifact resource has been created the provider will be interpolated directly, so you can resolve the chicken-and-egg problem by forcing that resource to be created before the others:

• terraform apply -target="atlas_artifact.debian7-puppet4-base"

After that you should have the artifact resource in the Terraform state and so a subsequent plan/apply of the whole configuration should work. It can then work on subsequent updates because the artifact resource will already exist in the state and so Terraform will refresh it before it makes any plan.

[phinze]

Yep - @apparentlymart is correct that this is specific to atlas_artifact and other resources like it. Keep an eye on #2976, which will indeed address this issue. Closing this thread to keep things consolidated.

[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 have found a problem that seems similar to this, please open a new issue and complete the issue template so we can capture all the details necessary to investigate further.