What is Continuous Integration in Jenkins | A Complete Beginners Guide | REAL-TIME Examples

• In this article you will get
• 1.What is Jenkins?
• 2.Continuous Integration
• 3.Benefits of Continuous Integration
• 4.Continuous Deployment
• 5.Benefits of Continuous Deployment
• 6.Conclusion

What is a Jenkins?

Jenkins is the powerful application that allows a continuous integration and continuous delivery of a projects, regardless of the platform are working on. It is the open-source automation server that is written in a Java and finds its use in automating a non-human part of the software development process with the continuous integration and encourages a technical aspects of a continuous delivery.With a Jenkins, organizations can accelerate a software development process by an automating a build and testing at a rapid rate. With more than a four hundred thousand installations and increasing an every day, Jenkins is the widely used application around world. One of the key advantages of a Jenkins is that it needs a little maintenance and has built-in a GUI tool for simple updates.

Jenkins also offers a customized solution as there are over a 400 plugins to support building and testing a virtually any project. The Jenkins project is the independent open source community under umbrella of a non-profit organization Software in a Public Interest, which owns the key project assets are including a Jenkins trademark. The project has its own decision-making process and also governance board. It manages and controls complete software delivery processes throughout an entire lifecycle, building, testing, documenting the software, deploying, and other stages of software development life cycle.

Continuous Integration

In a Continuous Integration after code commit, the software is built and tested immediately. But when consider the large project with many developers, commits are made more times during a day and with every commit, code is built and tested. Continuous integration is the process in which all the development work is integrated as early as be possible.

The resulting artifacts are be automatically created and tested. This process allows for an identifying errors as early as possible. If test is passed, the build is tested for a deployment. If a deployment is a success, the code is pushed to the production. This commit, build, test, and deploy is the continuous process and hence a name continuous integration/deployment.

Let us consider scenario where a complete source code of the application was built and then deployed on a test server for testing and then we can compare it with a Continuous Integration approach with the Jenkins. Upon a careful consideration, can come to a conclusion that this process has a many flaws.

Developers have to wait until a complete software is developed for a test results.There is a more probability that a test results might show multiple bugs. This will make it tough for a developers to locate those bugs because they have to check an entire source code of a application.

The entire software delivery process is be slowed.Continuous feedback pertaining to a things like coding or be architectural issues, build failures, test status and a file release uploads will be missing due to which a quality of software can go down.The whole process is the manual which increases a risk of frequent failure.

It is an evident from a above-stated problems that not only a software delivery process becomes slow but quality of software also goes down. This leads to a customer dissatisfaction.So to overcome such chaos there was dire need for the system to exist where developers can be continuously trigger a build and test for each change made in a source code. This is what a CI is all about. Jenkins is most mature CI tool available so let us see how a Continuous Integration with Jenkins overcame above shortcomings.

The basic functionality of a Jenkins is to execute a predefined list of a steps, for example, to compile a Java source code and build a JAR from the resulting classes. The trigger for this execution can be time or be an event-based say every 15 minutes or after a every new commit.

Let us consider a scenario for a same.When the developer commits a code to source code repository, the Jenkins server is already checking a repository at regular intervals for changes. Soon after a commit occurs, the Jenkins server detects changes that have occurred in a source code repository. Now, the Jenkins server will pull those changes and will start a preparing a new build. In case of build fails, the concerned team will notified. And if build is successful, then a build is deployed in a test server.

Jenkins can be customized according to requirements for a continuous integrations. Jenkins Pipeline is the suite of plugins that supports implementing and integrating a continuous delivery pipelines into the Jenkins. Pipeline adds a powerful set of an automation tools onto Jenkins. The pipeline can be configured for the creating the build with following steps: Prepare, test, package, publish, deploy.

Setting up Pipeline project means a writing a script that will sequentially apply some steps of a process we want to accomplish. After running it, Jenkins generates a feedback, if these constraints are good to go, an artifact is valid. And then a developers are notified about a build and test results. Jenkins will continue to the check a source code repository for further changes made in a source code, and the whole process will keep repeating.

Benefits of a Continuous Integration

• Spot any integration challenges are right away.
• The small change sets help in simple detection of an Integrations bugs.
• Increase a Code Coverage with a less number of changes.
• Build a Stuff Faster and never ship broken code.
• Consistency of a Build Process.
• Increases confidence in a software. Metrics generated from an automated testing and CI focus developers on a developing functional, quality code, and help to develop momentum in a team.

Continuous Deployment

Continuous deployment is the approach to releasing software on a production servers continuously in automated fashion. Continuous deployment can be thought of as extension of a continuous integration, aiming at minimizing lead time, a time elapsed between development writing one a new line of code, and this new code being used by a live users, in production.

It is a process of automating a code delivery tasks from the development to production environment consisting of a version control management, deployment on every environment followed by an automated testing, and taking decisions based on a results of the previous step.

So, once code passes through all stages of a compiling the source code, validating a source code, reviewing a code, performing unit and integration testing, and packaging application continuously, it will then be a deployed onto the test servers to perform a user acceptance tests. Once that is done, a software will be deployed onto a production servers for release. This is said to be a continuous deployment. If can set up a project server once, and can set up a Jenkins to deploy that a project again and again as develop, maintain, and expand it.

Benefits of a Continuous Deployment

• A Ship both cloud-native and traditional applications in the unified pipeline.
• There is the shift of focus onto actual testing as a repetitive tasks are automated.
• Create a workflows across development, testing, and production environments.
• Fault isolation is a simpler and quicker.

Conclusion

Hope have got clear understanding of a various terms like a Continuous Integrations, Continuous Delivery, and Deployment and also their respective benefits.