Support OCI registries in the terraform/opentofu manager

[norman-zon]

Idea

Extend the existing Terraform manager to support OpenTofu/Terraform modules and providers hosted in OCI registries using the oci:// scheme.

Background

Renovate already supports Helm charts in OCI registries but lacks support for OpenTofu modules and providers in OCI registries, despite OpenTofu's comprehensive OCI registry support.

Current Gap

Supported module sources: GitTags, GithubTags, TerraformRegistry
Missing: OCI registries (oci:// scheme)

Requested Features

1. OCI Module Support - Parse and update modules like:

   module "example" {
     source = "oci://example.com/repository-name:1.2.3"
   }

2. OCI Provider Mirror Support - Handle provider installations from OCI registries configured in .terraformrc:

   provider_installation {
     oci_mirror {
       repository_template = "example.com/providers/${namespace}/${type}"
       include = ["registry.opentofu.org/*/*"]
     }
   }

3. New Dependency Types:

   • oci_module for OCI-hosted modules
   • oci_provider for OCI-hosted providers

Implementation Notes

• Leverage existing OCI infrastructure (similar to Helm/Docker support)
• Handle OpenTofu artifact types: application/vnd.opentofu.modulepkg and application/vnd.opentofu.provider
• Support both tag and digest references
• Use existing OCI authentication mechanisms

Benefits

• Consistency with existing OCI support
• Enables updates for private infrastructure code repositories
• Supports modern artifact management workflows
• Full OpenTofu feature parity

This would extend Renovate's strong OCI registry support to cover all OpenTofu/Terraform dependency types.

EDIT: Opened a PR for this feature

[norman-zon]

Is there anything I could do to get my PR for this prioritised. We are very keen to start using OCI for opentofu modules, for many reasons, and this is the only thing holding us back.

[MPV]

Looks like that PR has merge conflicts as of today, will you take another look?