Jenkins is a self-contained, open source automation server(tool) for continuous development.

Jenkins aids and AUTOMATES CI/CD process.

It gets the checked in CODE from VCS like Git using a ‘git plugin’, build the source code, run test cases in a production-like environment and make the code release ready using ‘deploy’ plugin.

• These continuous DELIVERY pipelines are written in a ‘Jenkinsfile’ which is also checked into project’s source code and version controlled by Git.
• Pipelines are a continuous set of jobs that are run for continuous delivery and these jobs are integrated at every section of the workflow.
• Jenkins pipelines easily connect to Docker images and containers to run inside.
• Pipelines easily provide the desired test environment without having to configure the various system tools and dependencies.

Sample Jenkins file

• Jenkins will start the container- ubuntu with the latest image and execute the test case steps inside it.
• agent directive SAYS where and how to execute the pipeline
• jenkinsfile (declarative pipeline)
• pipeline
• Jenkins saves US the trouble of debugging after a huge commit history if there was a code break.