Jenkins (a fork of the Hudson project) is a Continuous Integration platform. The platform is primarily intended for the repeated execution and monitoring of build tasks, as well as the automated building and testing of applications. The many freely available plugins make it very easy to expand the functionality of Jenkins. An example of this is its integration with other systems (such as Sonar, Jira, or CloudBees) or changing its look and feel. It is possible to build a complete Continuous Delivery pipeline by using the right plugins.
There is also a GitLab plugin available to integrate Jenkins in a GitLab workflow. You can download and host Jenkins yourself, or buy capacity in the cloud.
As an example, we have ...