How do you roll back or revert changes when a CI build fails or introduces bugs?

To recover from a failed CI build, start by identifying the problem and its root cause using feedback, logs, version control, testing tools, git bisect, or git blame. Understanding the issue allows for effective resolution and prevention strategies for future builds.

To recover from a failed CI build, the primary approach is to rectify the problematic code and push a new commit to the repository. This action initiates a new CI build, aiming to address the issue. Alternatively, if fixing the code is impractical due to complexity, risk, or time constraints, consider other solutions like reverting or rolling back the code.

To revert the code is to undo a particular commit or a series of commits that caused the issue. Tools like git revert or svn revert can be utilized to generate a new commit that reverses the changes made in the previous commit(s). This method helps maintain the repository history without altering or deleting any commits. However, reverting the code may unintentionally remove desired changes or create new conflicts or dependencies. Hence, it is crucial to review and test the reverted code thoroughly before committing it to the repository.

One time at work I had to revert the code to make the pipeline execute successfully because the latest committed code has a build error.

To roll back the code is to revert your repository to a prior state where it functioned correctly. Tools like git reset or svn update can assist in moving your repository to a particular revision or tag that successfully passed the CI build. This process allows you to eliminate the faulty changes and begin anew from a reliable point. Nonetheless, rolling back the code may erase important changes or history from your repository. Hence, it is advisable to back up your repository before proceeding with a rollback and consider this option as a final solution.

To prevent future failures in the CI build process, adhere to best practices to enhance efficiency. Ensure thorough test coverage by writing comprehensive tests for critical features and scenarios, conduct local tests before pushing code, and utilize code reviews or merge requests for code validation. Implement feature branches, flags, or toggles to isolate and test new features independently. Employ automated tools like code linters and analyzers to maintain coding standards and identify issues. Consider continuous delivery or deployment to swiftly deploy software post successful CI builds, ensuring seamless production or staging environment updates.

To recover from a failed CI build, it's crucial to learn from mistakes and enhance your expertise. Utilize tools such as post-mortems, retrospectives, or root cause analysis to assess what transpired, identify improvements, and plan for the future. Employ feedback loops, metrics, and monitoring to gauge software performance and CI process effectiveness. Embrace failures as learning opportunities that can drive growth and foster innovation in your development practices.