Support for GitLab CI/CD Components

[scuba10steve]

What problem are you trying to solve?

For reference, here's a blog post that announced CI / CD components becoming generally available.

Having the ability to translate from the older style template inclusion to components would be helpful.

Example for migration: opentofu template -> opentofu component

What precondition(s) should be checked before applying this recipe?

Describe the situation before applying the recipe

This is not an extensive example, just a snippet

include:
  - template: OpenTofu/Base.latest.gitlab-ci.yml

Describe the situation after applying the recipe

include:
  - component: $CI_SERVER_FQDN/components/opentofu/job-templates@~latest
    inputs:
      # The version must currently be specified explicitly as an input,
      # to find the correctly associated images. # This can be removed
      # once https://gitlab.com/gitlab-org/gitlab/-/issues/438275 is solved.
      version: ~latest
      opentofu_version: 1.6.0

Have you considered any alternatives or workarounds?

Only alternative is to follow the aformentioned migration guide(s) that may or may not be available

Are you interested in contributing this recipe to OpenRewrite?

Yes, I would be interested in helping contribute this recipe.

[timtebeek]

Great to see; MergeYaml should be able to help you here; here's a video going in depth on that topic: https://www.youtube.com/watch?v=MRHHGxh4rdU

[timtebeek]

Quick status and a plan for finishing this one off.

Where we are today

The repo already has generic building blocks that cover most of what's needed:

• Templates: AddTemplate, ChangeTemplate, RemoveTemplate, search.FindTemplate
• Components: AddComponent (with version + inputs), ChangeComponent, search.FindComponent

What's missing is a dedicated migration recipe that turns a template: include into a component: include with inputs in a single step — i.e. the OpenTofu example in the issue description.

Proposed recipe: MigrateTemplateToComponent

A declarative composite that chains RemoveTemplate + AddComponent, plus one concrete specialization per well-known GitLab migration (Terraform → OpenTofu is the obvious first one).

Generic recipe (Java)

public class MigrateTemplateToComponent extends Recipe {
    @Option(example = \"Terraform/Base.gitlab-ci.yml\") String oldTemplate;
    @Option(example = \"\$CI_SERVER_FQDN/components/opentofu/job-templates\") String newComponent;
    @Option(example = \"~latest\") String version;
    @Option(required = false, example = \"opentofu_version: 1.6.0\") @Nullable List<String> inputs;

    @Override public List<Recipe> getRecipeList() {
        return Arrays.asList(
            new RemoveTemplate(oldTemplate),
            new AddComponent(newComponent, version, inputs, null)
        );
    }
}

Declarative specialization (YAML)

---
type: specs.openrewrite.org/v1beta/recipe
name: org.openrewrite.gitlab.MigrateTerraformTemplateToOpenTofuComponent
displayName: Migrate GitLab Terraform template to OpenTofu component
description: >-
  Replace the deprecated \`Terraform/Base.latest.gitlab-ci.yml\` template
  include with the OpenTofu CI/CD component, per the GitLab catalog migration guide.
recipeList:
  - org.openrewrite.gitlab.MigrateTemplateToComponent:
      oldTemplate: Terraform/Base.latest.gitlab-ci.yml
      newComponent: \$CI_SERVER_FQDN/components/opentofu/job-templates
      version: ~latest
      inputs:
        - 'version: ~latest'
        - 'opentofu_version: 1.6.0'

Test plan

• MigrateTemplateToComponentTest covering:
  • single-template file → replaced with component + inputs
  • multi-include file → only the targeted template is rewritten, siblings untouched
  • template not present → no-op
  • template with @ref suffix (handled by existing regex in RemoveTemplate)
  • no inputs provided → component added without an inputs: block
• MigrateTerraformTemplateToOpenTofuComponentTest using the exact before/after from this issue as a golden fixture
• Register the new specialization as an example in examples.yml

Follow-ups (out of scope for the first PR, but worth tracking)

1. A handful of other well-known template → component migrations GitLab publishes (e.g. SAST, Secret-Detection, Dependency-Scanning), each as a thin declarative recipe on top of MigrateTemplateToComponent.
2. A BestPractices-style composite "MigrateDeprecatedTemplatesToComponents" once we have >1 specialization.
3. Consider a FindMigratableTemplates search recipe that flags any template include that has a known component equivalent — useful for inventorying repos before running the migration.

Happy to put up a PR for the generic recipe + the Terraform→OpenTofu specialization as step 1 if that sounds right.

[scuba10steve]

I think this is what I was hoping for, so it should work. If you want to do the PR go for it. Otherwise I'll take care of it when I can find some free time.