Allow Variable to Control Provider Version

[stevegroner]

Terraform Version

Version: 11.1

Affected Resource(s)

AWS Provider

If this issue appears to affect multiple resources, it may be an issue with Terraform's core, so please mention this.

Terraform Configuration Files

# Create AWS Provider
provider "aws" {
  region = "${var.AWS_REGION}"
  version = "${var.PROVIDER_VERSION}"
}

Debug Output

N/A

Panic Output

N/A

Expected Behavior

The requested version of the provider be used. You should be able to centrally via variable define which provider version to pull. This will allow for me to modify when I want to update the provider to ensure compatibility before launching.

Actual Behavior

Successfully configured the backend "s3"! Terraform will automatically
use this backend unless the backend configuration changes.
Error getting plugins: provider.aws: invalid version constraint "${var.PROVIDER_VERSION}": Malformed constraint: ${var.PROVIDER_VERSION}

Steps to Reproduce

Create a provider using a variable in the version section

Important Factoids

N/A

References

N/A

[apparentlymart]

Hi @stevegroner! Sorry this doesn't work as you expected.

Unfortunately this situation is as designed, because the providers need to be resolved at terraform init time, and thus they cannot dynamically change (as a result of re-assigning variables) after initialization.

The intent of the provider version constraints is to express what your module is compatible with, which is a property of the code itself rather than of its execution environment. So far we've recommended to either use an exact version or a ~> "pessimistic" constraint for each provider in your root module, and thus the root module centrally defines which providers are to be used for the entire configuration, including all descendant modules.

We're planning to improve this via #16835, which will allow child modules to express that they require particular provider versions without creating their own provider configurations. As described in that issue, we'd recommend that descendant modules use >= constraints to state their minimum compatible version while root modules would continue to use exact or ~> constraints to set the "top limit" on which version can be installed.

[dendrochronology]

Could someone please update the relevant docs to state why string interpolation isn't supported here? That would be a big help!

I don't see any mention of it here:

https://www.terraform.io/docs/configuration/providers.html#provider-versions

[aslafy-z]

This issue should be closed.

[bflad]

Thank you for the heads up, @aslafy-z! Indeed, it looks like this issue should be closed out, now that the terraform configuration block supports required_providers to set provider version constraints centrally per module, and the provider configuration block version argument has been explicitly deprecated in of Terraform CLI version 0.14 and later.

More information about specifying provider requirements (such as versioning) can be found in the Terraform configuration language documentation: https://www.terraform.io/docs/language/providers/requirements.html

[github-actions]

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