Jenkins - Interview Questions

What is Jenkins, and where does it fit in the DevOps landscape?

 

Jenkins is an automation tool used for building, deploying and automating any project.

Jenkins is architected for plugin support, and can integrate with practically every tool in the CICD tool chain.

Jenkins, along with it's integration abilities with other CICD tools provides unlimited CICD capabilities.

What language is Jenkins developed, what is the installation process?

 

Jenkins was developed using Java programming language.

Jenkins is typically run as a standalone application using the built-in Jetty Servlet/Application container. Jenkins can also be run as a servlet in other application servers such as Apache Tomcat.

Jenkins can be run on operating systems - macOS, Windows,and Linux - on containers such as Docker containers - and on cloud services such as AWS and Azure.

What are the different scope for credentials in Jenkins?

 

Credentials in Jenkins can be set up at two scopes.

Global scope: - Applies to Jenkins, nodes, items, and all descendant items. This scope is typically used from pipeline projects.

System scope Applies to Jenkins and nodes only. This scope is typically used for system admin functions such as email authentications, agent connections etc.

What are the different kinds of credentials that can be setup in Jenkins?

 

Credentials in Jenkins can be of different kinds - Username with password, SSH with private key, Secret file, Secret text, PKCD certificate etc.

What is Jenkins Controller?

 

Jenkins controller is the central process which stores configurations, loads plugins, renders user interfaces, manages agents, and executes pipeline tasks either directly or more typically via agents.

What are Jenkins Agents?

 

Jenkins agents are individual nodes - typically a machine, or container - which connects to a Jenkins controller and executes pipeline tasks when directed by the controller.

What is Jenkins pipeline? What are the different options of creating a Jenkins pipeline?

 

Jenkins pipeline is suite of plugins that implements and integrates continuous delivery pipelines into Jenkins.

There are three ways to create a Jenkins pipeline

Blue Ocean - A UI tool to visually create pipelines

Classic UI - Jenkins classic UI through which you can create a basic pipeline.

SCM - Write a JenkinsFile manually and commit to your projects code repository which will be picked up and processed by Jenkins.

For enterprise projects, and in general as a best practice it is better to create a JenkinsFile and check the file into the source control repository.

 
Subscribe to our Questions

 

DevOps - Interview Questions

DevOps BasicsGITJenkinsJFrogDockerDocker SwarmKubernetes
 
RECOMMENDED RESOURCES
Behaviorial Interview
Top resource to prepare for behaviorial and situational interview questions.

STAR Interview Example