Continuous Integration (CI) is one of the most important pillars of Extreme Programming (XP). Continuous Integration has been one of GitLab's most popular features since it was built in version 8. It is very popular with independent developers and open source projects and is currently gaining popularity in other market segments.

Getting started is easy. As we showed you earlier, in Chapter 10, Create Your Product, Verify, and Package it (in the Release and Configure sections), Auto DevOps is switched on by default, so that when adding code to a project, a deployment pipeline is automatically set up in which various jobs are running. These jobs will be run by a GitLab Runner, which you will have to set up. This is completely configurable to the wishes of the developer. The results of the jobs are collected and showed as passed or failed and are part of the logic in the pipeline. Based on the result, other automation in the pipeline can be triggered. The basis for this functionality is in the .gitlab-ci.yml file. If this file is present in a project, it will be parsed and different pipelines and jobs will start running.

In this chapter, we will be covering the following topics:

• Pipelines
• Jobs
• Creating .gitlab-ci.yml
• Configuring a Runner