feat: Add gitlab_repository_file data source

[petrmvala]

This data source is part of Gitlab API.

Closes: #927

Description

PR Checklist Acknowledgement

• I acknowledge that all of the following items are true, where applicable:
  • Resource attributes match 1:1 the names and structure of the API resource in the GitLab API documentation.
  • Examples are updated with:
    • A *.tf file for the resource/s with at least one usage example
    • A *.sh file for the resource/s with an import example (if applicable)
  • New resources have at minimum a basic test with three steps:
    • Create the resource
    • Update the attributes
    • Import the resource
  • No new //lintignore comments were copied from existing code. (Linter rules are meant to be enforced on new code.)

[timofurrer]

Could you give this approach a shot:

https://github.com/gitlabhq/terraform-provider-gitlab/blob/main/internal/provider/data_source_gitlab_project_issue.go

For that to work you may also add the additional read-only fields to the gitlab_repository_file resource as Computed.

If you don't want I can later or tomorrow give it a shot, no worries.

Also, the examples are missing ;)

[petrmvala]

Well, I posted this because I was not sure why does this error out and wanted to ask for advice https://github.com/gitlabhq/terraform-provider-gitlab/runs/5461795214?check_suite_focus=true#step:6:34

But the approach with the schema seems interesting.

[timofurrer]

@petrmvala It's unrelated, but probably related to #820 ...

[timofurrer]

Looks good, I think we leave the things with datasourceSchemaFromResourceSchema() for now and go with the proposed approach.

[timofurrer]

@petrmvala I took the liberty and followed up on this.

I'll merge once the checks passed!

Thank you very much for the contribution! 🎉

[github-actions]

This functionality has been released in v3.13.0 of the Terraform GitLab Provider. Please see the Terraform documentation on provider versioning or reach out if you need any assistance upgrading.

For further feature requests or bug reports with this functionality, please create a new GitHub issue. Thank you!