Most Asked Jenkins Interview Questions & Answers

Q. What is Jenkins?

Ans: Jenkins is an open-source tool available with a large number of plugins. This tool is handy for continuous integration (CI). It automates the cycle of complete software development life cycle and alerts stakeholders if there are some problems in a specific phase.

Here, we will cover the frequently asked interview questions and answers on Jenkins. These interview questions definitely help you to succeed in getting a job. Also, it helps you understand more topics related to Jenkins.

Q. What is continuous integration?

Ans: Continuous integration is a term used for interlinking all activities of software development. For instance, the developer writes a small piece of code and commits it to the main repository. Simultaneously, automation testing of code starts with defined test cases, and the developer knows how many test cases are passed and how many are failed. It helps and allows the team to monitor software development progress and detect problems in code early. This ultimately helps in the early delivery of software.

Q. List out some tools which can be used as an alternative to Jenkins.

Ans: CruiseControl, GoCD, Integrity, IBM UrbanCode, AutoRABIT, buildkite, etc. are some of the tools that can be used as an alternative to Jenkins.

Q. Which version control tools are supported by Jenkins?

Ans: Subversion, Mercurial, Perforce, Clearcase, Git, and Maven are some of the version control tools supported by Jenkins.

Q. Is Jenkins follow client-server architecture?

Ans: Jenkins has both options available - standalone mode and client-server mode. Client-server architecture helps in scalability, in which the master manages all activities, and the client can be added by adding nodes in the configuration section.

Q. Which operating system is best for hosting Jenkins masters and nodes?

Ans: Linux flavor operating system is best for hosting Jenkins master as hardware requirements are less for Linux operating system. It is recommended to use a familiar operating system in which you can harden security configuration properly. A node can be installed on any operating system.

Moreover, Jenkins is able to install all operating systems that support Java (JRE version 4 and above).

Q. What authentication methods are available for Jenkins?

Ans: Lightweight Directory Access Protocol (LDAP), Jenkins’s own user database, Unix database, and delegate to servlet container options are the authentication methods available for Jenkins.

Jenkins plugins also available for Central Authentication Service for single sign-on, Active
Directory, Google login, and Kerberos SSO, which helps to enhance security.

Q. What are the minimum and recommended hardware requirements for installing Jenkins?

Ans: Minimum hardware requirement: 256 MB of RAM, 1 GB of HDD

Recommended hardware requirement: 1 GB of RAM, 50 GB of HDD

Q. Can docker be used for installing Jenkins?

Ans: Docker provide an isolated environment for software application installation. Jenkins also downloads as a read-only image and runs in docker.

Q. Where exactly Jenkins is accessible by users?

Ans: Jenkins is accessible via URL on browsers. Currently, Jenkins supports all major browsers such as Google Chrome, Apple Safari, Mozilla Firefox, MS IE, and MS Edge.

Q. What is the JENKINS_HOME directory?

Ans: JENKINS_HOME directory stores all its configurations. In other words, you can say it stores the state of Jenkins on the JENKINS_HOME directory.

It is recommended that JENKINS_HOME/secrets should be assigned read permission for only users of the Jenkins process.

Q. What is an agent?

Ans: Agent may be any machine or container that connects with the Jenkins controller. It performs actions whenever the controller triggers a task.