Jenkins interview questions and answers. Jenkins is an open-source automation server. It helps automate the parts of software development related to building, testing, and deploying, facilitating continuous integration and continuous delivery. It is a server-based system that runs in servlet containers such as Apache Tomcat. It is written in Java with plugins built for Continuous Integration purposes.
It also allows continuous delivery of the software by integrating with many testing and deployment technologies. With Jenkins, organizations can accelerate the software development process through automation. Jenkins integrates development life-cycle processes of all kinds, including build, document, test, package, stage, deploy, static analysis, and much more.
This article will explore the top 20 Jenkins interview questions and answers that are usually asked during Jenkins or DevOps interviews.
Top 20 Jenkins Interview Questions and Answers
Below are the top 20 Jenkins interview question and answers that you need to know:
1. What is Continuous Integration?
Within software growth, when many developers or crews are operating on various sections of the corresponding web application, we must implement integration tests by combining all modules. To do that, an automated method for every piece of (pivotal training) code is executed on a periodic basis so that all your code gets examined.
2. What are the Requirements for Using Jenkins?
In order to use Jenkins, you need:
- A source code container, which is accessible, for instance, a Git container.
- A build script, for example, a Maven script, indicated within the container.
3. What are the Benefits of Jenkins?
Jenkins provides a lot of benefits, some of them are following:
- In integration platforms, crashes are caught.
- After every code commit, it develops a warning build report and produces a warning.
- To admonition developers regarding build report progress or abortion, it is combined with LDAP mail server.
- Succeeds constant integration, agile improvement and test-driven progress.
- By easy steps, the Maven discharge project is electronic.
- Simple tracking of faults at an initial stage in a progressive atmosphere than production.
4. How to Move or Copy Jenkins from One Server to Another?
Drive a work from one installation of Jenkins to another by copying the relevant work directory:
- By making the clone of a job directory by another name. Create a copy of a previously existing job.
- Renaming an existing job by renaming a directory.
5. What are the Commands that are Used to Begin Jenkins Manually?
To begin Jenkins manually, you can use the following commands:
- (Jenkins_URL)/safeRestart: Allows all running builds to complete and then restarts..
- (Jenkins_URL)/restart: Forces a restart without waiting for builds to complete.
6. Discuss Some of the Valuable Plugins in Jenkins.
Some of the useful plugins in Jenkins involve:
- HTML Publisher
- Copy Artifact
- Maven 2 Project
- Amazon EC2
- Join
- Green Balls
7. How to Deploy a Custom Build of a Core Plugin?
To deploy a custom field of a core plugin, follow these steps:
- Stop Jenkins.
- Trace the custom HPI to $Jenkins_Home/plugins.
- Eliminate the previously expanded plugin directory.
- Make an empty file called .hpi.pinned.
- Start Jenkins.
8. How to Build a Backup or Copy Files in Jenkins?
Jenkins preserves all the settings, build artifacts and logs in its home directory. To formulate a back-up of your Jenkins settings, simply copy this directory. Also, copy a job directory and rename the directory to replicate a job.
9. How to Clone a Git Repository with Jenkins?
Just enter the email and username of your Jenkins system. For that, you need to switch to your job directory and execute the “git config” command. With this, you can clone a Git repository with Jenkins.
10. How Can You Setup Jenkin Jobs?
To create a project that is handled via jobs in Jenkins. Select a new item from the menu, enter a name for the job and select the free-style job. Then click OK to create a new job in Jenkins. The next page enables you to configure your job.
11. What are the Two Main Components Jenkins is Mainly Integrated with?
Jenkins is mainly integrated with the following two components:
- Version control systems like GIT, SVN, etc.
- Build tools like Apache Maven.
12. What is the Difference between Maven, Ant, and Jenkins?
Ant is a Java-based build tool that has become a de-facto standard for building Java projects. However, you may have heard of another popular build tool called Maven, which is different in that it enforces a common project structure as well as providing ways to compile and build applications.
The most fundamental difference is that Maven and Ant are build technologies, whereas Jenkins is a continuous integration tool.
13. Which SCM Tools does Jenkins Support?
SCM (Source Code Management) is a basic but essential part of any project developed in the current IT world. It is a kind of software that developers usually use to manage their source code. It plays a vital role in the process of software development because it ensures that every member of the team stays on top of source code changes in an ongoing project.
Jenkins supports the following SCM tools:
- AccuRev
- CVS
- Subversion
- Git
- Mercurial
- Perforce
- Clearcase
- RTC
14. What is Continuous Integration in Jenkins?
In software development, multiple developers or teams work on different segments of the same web application. So you have to perform integration tests by integrating all modules. To do that, an automated process for each piece of code is performed on a daily basis so that all your code gets tested. This process is known as continuous integration.
15. What is the Relation between Hudson and Jenkins?
Hudson was the earlier name and version of current Jenkins. After some issues, the project name was changed from Hudson to Jenkins.
16. What are the Parameters in Jenkins?
Parameters are supported by the Agent section and they are used to support various use-cases pipelines. Parameters are defined at the top level of the pipeline or inside an individual stage directive.
17. Why is Continuous Integration Important?
There are two main reasons due to which continuous integration is important:
- Defects found earlier cost less to fix. When a flaw is found immediately after the developer codes it, it takes very less time to fix it as compared to finding the defect a month later.
- Reduced time to market. Software is always tested. So, it is always ready to move to further environments.
18. How is Continuous Integration Implemented?
Different tools for supporting Continuous Integration are Hudson, Jenkins, and Bamboo. Jenkins Windows Server is the most popular one currently. They provide integration with various version control systems and build toll.
19. What is SSH?
SSH (Secure Shell) is a program to log into another computer over a network, execute commands in a remote machine, and move files from one machine to another. It provides strong authentication and secure communications over insecure channels. It is intended as a replacement for rlogin, rsh, and rcp.
20. Why is DevOps Necessary?
Corporations are now facing the necessity of more, quicker, and improved requests to see the ever more persistent demands of mindful users to decrease the time to market. Unfortunately, DevOps often benefits placement to occur very profligately.
Jenkins Interview Questions and Answers Final Thoughts
We learned that Jenkins is a popular DevOps open source automation server. It is used to automate the non-human part of software development and supports continuous integration and continuous delivery.
If you are preparing for DevOps interviews, you cannot undermine the importance of Jenkins. We hope this article helps you in learning or refreshing your knowledge of Jenkins.
