What is the simplest CI pipeline a beginner can build?
The four basic steps
Most pipelines begin with a trigger, usually a push to the main branch or a pull request. The runner then downloads the code, installs the libraries, and runs the test suite. If any step returns an error, the pipeline stops and reports which step failed.
- Trigger on push or pull request
- Check out the repository
- Install dependencies
- Run tests and fail on errors
Keeping it reliable
Pin versions of your language and tools so builds do not change without warning. Keep the pipeline fast by caching dependencies when your platform allows it. A slow or flaky test suite teaches people to ignore red builds, which defeats the point.
Adding deployment later
Once tests pass consistently, you can add a deployment job that runs only on the main branch after the checks succeed. Start with a staging environment if you have one. Keep the deployment step small so it is easy to read and debug.
Write the pipeline file in the repository so the setup is versioned along with the code. Anyone on the team can then see exactly what runs on each push. Keep the first version short enough that a new team member can read the whole file in one sitting.
Common mistakes
- Adding deployment before the tests are dependable.
- Leaving dependency versions unpinned so builds break unexpectedly.
- Ignoring failing builds for days until nobody trusts the results.
