The application development life cycle is traditionally a lengthy manual process. In addition, it requires effective collaboration between development and operations teams. The CI/CD pipeline is a demonstration of automation involved in the application development lifecycle that contains automated build execution, automated test execution, notifications to stakeholders, and deployment in different runtime environments. Effectively, a deployment pipeline is a combination of continuous integration and continuous delivery, and hence a part of DevOps practices. The following figure depicts the pipeline process. Depending on the culture of organization and the available tools, the flow and tools may differ:

Members of the development team check code into a source code repository. Continuous integration products such as Jenkins are configured to poll changes from the code repository. Changes in the repository are downloaded to the local workspace and Jenkins triggers a build process that is assisted by Ant or Maven or Gradle or any build script. Automated test execution, unit testing, static code analysis, reporting, and notification of successful or failed build processes are also parts of the Continuous Integration process.

Once the build is successful, it can be deployed to different runtime environments such as testing, pre-production, production, and so on. Deploying a WAR file in terms of a JEE application is normally the final stage in the deployment pipeline. However, after the deployment of this package into a pre-production environment, functional and security testing can be performed.

One of the biggest benefits of the pipeline is a faster feedback cycle. Identification of issues in the application in early stages and no dependency on manual effort make this entire end-to-end process more effective.

In the following chapters, we will see how Jenkins can be used to implement CI and CD practices in modernizing the culture of an organization.