Industry Use-Cases of Jenkins

What is Jenkins?

Jenkins is an open-source Continuous Integration server capable of orchestrating a chain of actions that help to achieve the Continuous Integration process (and not only) in an automated fashion.

Salient Features Of Jenkins

Jenkins is more functionality-driven rather than UI-driven hence, there is a learning curve involved in getting to know what is Jenkins. Here are the powerful developer-centric features offered by Jenkins:

1. Easy Installation & Configuration

Jenkins is a self-contained Java program that is agnostic of the platform on which it is installed. It is available for almost all the popular operating systems such as Windows, different flavors of Unix, and Mac OS.

2. Open-Source

As it is open-source, it is free for use. There is a strong involvement of the community which makes it a powerful CI/CD tool. You can take support from the Jenkins community, whether it is for extensibility, support, documentation, or any other feature related to Jenkins.

3. Thriving Plugin Ecosystem

The backbone of Jenkins is the community and the community members have been instrumental in the development (and testing) of close to 1500+ plugins available in the Update Center.

4. Easy Distribution

Jenkins is designed in such a manner that makes it relatively easy to distribute work across multiple machines and platforms for the accelerated build, testing, and deployment.

Architecture Of Jenkins

Before we dive into how does Jenkins works, we must understand the architecture of Jenkins. These are the series of steps that outlines the interaction between different elements in Jenkins:

  • The repository is continuously checked by the Jenkins CI server for any changes (either in the form of code or libraries) and changes are pulled by the server.
  • In the next step, we ensure that the build with the ‘pulled changes’ is going through or not. The Build server performs a build with the code and an executable is generated if the build process is successful. In case of a build failure, an automated email with a link to build logs and other build artifacts is sent to the developer.
  • In case of a successful build, the built application (or executable) is deployed to the test server. This step helps in realizing continuous testing where the newly built executable goes through a series of automated tests. Developers are alerted in case the changes have caused any breakage in functionality.
  • If there are no build, integration and testing issues with the checked-in code, the changes, and tested application are automatically deployed to the Prod/Production server.
  • A single Jenkins server might not be sufficient to handle the load that comes with large-scale software projects.

Continuos Integration/Continuous Development

Continuous integration is a process in which multiple commits are made every day and each commit code is built and tested immediately. Once the test is passed the build is tested for deployment and then it is sent to production. A CI/CD pipeline consists of a Continuous Integration server like Jenkins, a Source Control tool, a Build tool, and an automation testing framework like Selenium, Appium, etc. There are many benefits of continuous integration and according to the project requirement, the development team can choose the best continuous integration tools.

Jenkins at Netflix

Conclusion

Jenkins is like the soul of the continuous integration process as it builds and tests the app continuously which makes it easier to integrate changes to the process. Most of the process is automated and this saves time and effort which can be used to perform other tasks related to the delivery. It has some issues like the old UI but the benefits like an active opensource community overshadow the little disadvantages. This is why Jenkins is the most popular CI server among the developers.

I automate things 😉