What problem are you facing?

Presently, the registry URL is hard-coded to registry.terraform.io.

With the advent of OpenTofu, more registries have popped up, including better support for internal/enterprise/corporate "private" registries. A user of this tool should be able to specify the preferred URL pattern to use for the registry.

How could terraform-docs help solve your problem?

The three most popular public registries (as of today's date) have the following URL patterns (arbitrarily picking version v5.65.0).

• https://registry.terraform.io/providers/hashicorp/aws/5.65.0/docs
• https://search.opentofu.org/provider/hashicorp/aws/v5.65.0
• https://library.tf/providers/hashicorp/aws/5.65.0

I propose that as a CLI flag and config file entry, a user should be able to provide a keyword to signify one of the popular public registries, or a Go-template URL pattern for a custom/private registry.

As an example, let's look at settings. We could add a new entry called registry-url, which would accept a string.

settings:
  anchor: true
  color: true
  default: true
  registry-url: ''
  ...

Reviewing When not to use Plain Scalars to understand which characters can be used at the beginning of a string value, unquoted, it looks like :<space> is unavailable, but :<nospace> should be valid.

We could use certain "short" strings as placeholders for well-known values, then fall back to Go-template values for custom URLs.

• :terraform:
• :opentofu:
• :library-tf:
• https://registry.company.com/internal-registry/{{.Namespace}}/{{.Provider}}/{{.ProviderVersion}}/docs

The last of these would likely need to be quoted, which is reasonable.

settings:
  default: true
  registry-url: :library-tf: # I *think* this is valid. Untested. Can still be quoted.
  ...

settings:
  default: true
  registry-url: 'https://registry.company.com/internal-registry/{{.Namespace}}/{{.Provider}}/{{.ProviderVersion}}/docs'
  ...

Or if you'd prefer to simply require a quoted value, maybe a different meta-character would be preferred over : for readability. Perhaps @?

settings:
  default: true
  registry-url: '@opentofu'
  ...

Just some ideas.

Related improvements

If a provider has a version constraint (e.g., ~> 4.60), then instead of always linking to the latest version, we should honor the version constraint when we create the registry links. Continuing to use hashicorp/aws as an example, the most appropriate version for the ~> 4.60 constraint is 4.67.0.

In my proposal above, where I mentioned .ProviderVersion as a Go-template variable, that variable would be set to 4.67.0 instead of latest.

Why? Many corporations have large numbers of apps in various states of maintenance, and may be using an older version of Terraform or Terraform Module or Terraform Provider until they have a chance to update. My previous company has in-use versions of Terraform 0.7 that just never got updated. Being able to provide accurate documentation for well-crafted projects should be possible, and always linking to latest is inaccurate.