String is not interpolated for resource provider alias

[scriptjs]

The provider cannot be interpolated from an expression to look up the appropriate provider alias.

Terraform Version

0.9.4

Affected Resource(s)

Please list the resources as a list, for example:

• openstack_images_image_v2

Terraform Configuration Files

variable openstack_tenants {
  default = [
    "openstack.aliased_tenant_0",
    "openstack.aliased_tenant_1"
  ]
}
variable name {}
variable local_file_path {}
variable name {}

provider "openstack" {}
provider "openstack" {
  alias = "aliased_tenant_0"
  tenant_name = "aliased_tenant"
}
provider "openstack" {
  alias = "aliased_tenant_1"
  tenant_name = "another_tenant"
}

resource "openstack_images_image_v2" "tenant_images" {
  provider = "${element(var.openstack_tenants, count.index)}"
  name = "${var.name}"
  local_file_path = "${var.local_file_path}"
  container_format = "bare"
  disk_format = "qcow2"
  visibility = "private"
  min_ram_mb = "384"
  min_disk_gb = "8"
  region = "${var.region}"
  count = "${length(var.openstack_tenants)}"
}

Expected Behavior

Interpret the expression to produce the provider alias in the resource to enable execution of the loop.

Actual Behavior

Throws an error:

Error asking for user input: 1 error(s) occurred:

* openstack_images_image_v2.tenant_images: provider ${element(var.openstack_tenants, count.index)} couldn't be found

Steps to Reproduce

1. terraform plan

NOTE: This works when provider in the resource is set to what ought to be interpolated ie. provider = "openstack.aliased_tenant_0" but does not work when an expression is used that ought to be first evaluated. "openstack.aliased_tenant_0" and "openstack.aliased_tenant_1" are contrived in the above example so as not to leak identities of tenants on the private cloud.

[apparentlymart]

Hi @scriptjs!

At present this is an intentional limitation due to the fact that providers need to be known very early on in Terraform's lifecycle, before interpolation is possible. This might change in future, but there are no immediate plans for this.

The existing issue #3656 is already covering this request, so I'm going to close this one just to consolidate the discussion over there.

[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.