Migration Guide (GitLab → GitHub)¶

Core Differences¶

GitLab CI	GitHub Actions
`include: project:` merges YAML	`uses:` calls reusable workflows
Hidden jobs (`.template`) with `extends:`	Composite actions
`rules: exists: [pom.xml]`	Detection job + conditional `if:`
`variables:`	`inputs:` + `env:`
`services: [docker:dind]`	Docker pre-installed on runners
`artifacts: reports: junit:`	`dorny/test-reporter`
`$CI_REGISTRY_IMAGE`	`ghcr.io/${{ github.repository }}`
`$CI_COMMIT_SHA`	`${{ github.sha }}`
`pages:` job	`actions/deploy-pages`

What Changed in the Architecture¶

On GitLab, Code Haven Farm used include: to merge ~37 template files into a consumer pipeline. Each template was a small, focused file. The consumer's pipeline inherited all jobs automatically.

GitHub Actions doesn't support YAML merging. Instead, we use:

One orchestrator workflow (devsecops.yml) that consumers call
13 domain-specific reusable workflows (prefixed with _) for each concern
Composite actions for reusable step sequences

Variable Mapping¶

GitLab Variable	GitHub Actions Equivalent
`$CI_COMMIT_SHA`	`${{ github.sha }}`
`$CI_COMMIT_REF_NAME`	`${{ github.ref_name }}`
`$CI_MERGE_REQUEST_ID`	`${{ github.event.pull_request.number }}`
`$CI_DEFAULT_BRANCH`	`${{ github.event.repository.default_branch }}`
`$CI_PROJECT_PATH`	`${{ github.repository }}`
`$CI_JOB_TOKEN`	`${{ secrets.GITHUB_TOKEN }}`
`$CI_REGISTRY`	`ghcr.io`
`$CI_REGISTRY_IMAGE`	`ghcr.io/${{ github.repository }}`

For the complete detailed mapping, see MIGRATION-REPORT.md.