Replicating GitLab's Centralized CI/CD Pipeline in GitHub Using a Central Repository to Avoid Duplication

Introduction Transitioning from GitLab’s centralized CI/CD pipeline structure to GitHub Actions presents a unique challenge for developers accustomed to GitLab’s modular approach. In GitLab, a central 'pipelines' repository acts as a single source of truth, referenced by individual projects via the include keyword. This mechanism eliminates duplication of CI/CD configurations, ensuring consistency and reducing maintenance overhead. However, GitHub Actions operates under a different paradigm, where workflows are typically defined within the .github/workflows directory of each repository. This disparity forces users to rethink how to achieve centralization without GitLab’s native include functionality. The core issue lies in GitHub’s scoping rules for reusable workflows. While GitHub supports uses to reference workflows from a central repository, these workflows must reside in a publicly accessible repository or the same repository. This constraint introduces versioning challenges , as changes to the central workflow can inadvertently break dependent projects if not managed carefully. For instance, updating a reusable workflow without tagging a stable version can lead to inconsistent behavior across projects, as GitHub defaults to using the latest commit. Another friction point is the lack of direct equivalence between GitLab’s include and GitHub’s uses . GitLab’s include allows for seamless integration of CI configurations, treating the included file as part of the local context. In contrast, GitHub’s uses references an external workflow, which operates in its own scope . This means inputs and outputs must be explicitly defined, increasing the complexity of migration. For example, a GitLab CI job that references a shared script might fail in GitHub Actions if the script relies on environment variables not passed through the uses interface. To address these challenges, developers must adopt a hybrid approach . Composite actions , which bundle multiple steps into a sin