Best Jenkins Interview Questions to Prepare for a DevOps Interview

When it comes to DevOps, there are a galore of tools that one should know. Jenkins is one of the most sought-after tools by DevOps professionals. So, in order to successfully land a DevOpsAMP job role, you must have a good working experience with the popular automation server.

To help you clear a DevOps job interview, we’ve put up a list of the top 15 Jenkins interview questions. This list includes basic, intermediate, and advanced questions.

Jenkins Interview Questions

1. What is Jenkins?

Answer: Jenkins is a free and open-source automation server for developing and testing software. The tool makes it simple for developers to integrate project updates.

Jenkins’ primary goal is to keep track of the version control and, if necessary, to start and supervise a build system. It keeps track of the entire procedure and sends out reports and notifications to keep you informed.

Jenkins is extensively used for a variety of purposes. The popular CI tool is used by developers and testers to detect and automate build software testing throughout the software development lifecycle.

They utilize it to keep track of the code in real-time and incorporate changes into the build. Jenkins, it turns out, is an excellent choice for constructing a CI/CD pipeline due to its plugin capabilities and ease of use.

2. Enumerate the major features of Jenkins.

Answer: Following are some of Jenkins’ most important features:

• It’s a completely free and open-source server automation program.
• Jenkins comes with a plethora of plugins.
• It’s simple to set up and deploy across a variety of operating systems.
• Supports CI/CD pipeline.
• Cycles of rapid release.
• Upgrades are simple.

3. What is the procedure for installing Jenkins?

Answer: To install Jenkins:

1. Install Java and Apache Tomcat Server.
2. Next, download and deploy the Jenkins .war file.

4. How will you start Jenkins?

Answer: These are the steps to start Jenkins:

1. Start the command prompt.
2. Navigate to the directory where the Jenkins .war file is located once the command prompt has opened.
3. After that, execute the following command:

Java -jar Jenkins.war

5. How does Jenkins use Groovy?

Answer: Apache Groovy is a dynamic object-oriented programming language for Java platforms that is used as a scripting language. The Jenkins pipeline is orchestrated with Groovy, which allows different teams to contribute in different languages.

The syntax of Groovy is quite similar to the syntax of Java, making it easier to integrate into the Java environment. Java compatibility and development support are two important features of the language.

6. How are Continuous Integration, Continuous Delivery, and Continuous Deployment different?

Answer: Continuous Integration (CI) is a DevOps software development approach that allows developers to combine/merge their code changes in a common repository so that automated builds and tests may be done.

Continuous Delivery (CD), on the other hand, is the process of creating, testing, and deploying software code improvements. CD’s most important feature is that the code is always deployable. The final stage of the DevOps process is Continuous Deployment (CD). Any developer modifications that are automatically released from the repository to the production stage are referred to as this.

7. What is a Continuous Integration/Continuous Delivery (CI/CD) pipeline?

Answer: The backbone of the DevOps strategy is the CI/CD pipeline. The pipeline is in charge of creating codes, testing them, and releasing new software versions.

8. What is a Jenkins pipeline and how does it work?

Answer: The pipeline symbolizes the continuous delivery and integration of all jobs across the SDLC and DevOps life cycle. The Jenkins pipeline is a series of plugins that help Jenkins users set up and integrate continuous delivery pipelines.

Jenkins links this pipeline in a certain format. The Jenkins pipeline handles a number of issues, such as maintaining hundreds of jobs and maintaining deployment without resorting to more sophisticated approaches.

9. In Jenkins, what are the three basic types of pipelines?

Answer: Jenkins pipelines are divided into three categories:

1. CI/CD pipeline.
2. Scripted pipeline.
3. Declarative pipeline.

10. What are the prerequisites for working with Jenkins?

Answer: You’ll need the following to utilize Jenkins:

• A repository of source code that can be accessed, such as a Git repository.
• A build script, such as a Maven script.

11. Enumerate processes involved in moving or copying Jenkins from one server to another.

Answer: Jenkins can be moved or copied from one server to another in a variety of ways:

• A task can be moved from one Jenkins installation to another by simply copying the job directory.
• You can duplicate an existing job by creating a clone of the job directory with a unique name.
• You can also just rename a directory to rename a current job.

12. What is Jenkins’ methodology for working?

Answer: Jenkins follows the following procedure:

• It monitors repository changes on a frequent basis, and developers must protect their code on a regular basis.
• Jenkins detects the changes and uses them to prepare a new build after they’ve been declared.
• The automation server will then proceed through the phases of its standard workflow. The process will progress to the next level as one stage is completed.
• If a stage fails, Jenkins will halt the build and send an email to the team involved. When the code is successfully completed, it is installed on the appropriate server, and testing may begin.
• Jenkins communicates the results with the team that is utilizing it after the successful testing phase.

13. What is DSL in Jenkins?

Answer: DSL is an acronym for Domain Specific Language. Jenkins Job DSL is a plugin that allows us to programmatically define tasks with minimal effort. In Jenkins, you can use a Groovy-based language to describe your jobs. The Jenkins Job DSL plugin helps to build job versions and manage records.

14. Explain the approach for setting up third-party tools in Jenkins.

Answer: The process of configuring third-party tools in Jenkins is broken down into four major steps:

1. Install the third-party application.
2. Then, to support the third-party tool, install a Jenkins plugin.
3. Now, go to the Manage Jenkins section and configure the tool.
4. Finally, your plugin is complete and ready to use.

15. What is a Jenkinsfile?

Answer: A Jenkinsfile is a text file that contains a Jenkins pipeline definition and is checked into a source control repository. It allows for pipeline code review and iteration. It also allows for a pipeline audit trail.

Conclusion

Jenkins interview questions are usually asked in a DevOps-based job interview. You should be well prepared for a Jenkins interview by this point. In addition to the automation server, there are several other tools that you should know about to clear a DevOps interview, including Ansible, Docker, and GitHub.

What Jenkins interview questions were you asked during your DevOps job interview? Share in the comments section below.