Jenkins Interview Questions and Answers

• Easy to install on multiple OS
• Easy-to-use with good User Interface
• Easily scalable with over 400 third party plugin support
• User Interface is very friendly with respect to customization. The setup environment can be configured inside.
• JUnit; a test harness is integrated with Jenkins so as to provide results in graphical and tabular forms
• Inside the environment, build scheduling is based on Cron Expression

Note: These are basic questions that are asked during a Jenkins interview question for DevOps candidates.

A pipeline in Jenkins refers to a suite of plugins that help implement & integrate Continuous Delivery Pipelines throughout Jenkins. A continuous delivery pipeline is an automated expression for getting software from version control right through to your users and consumers.

There are two types of pipeline syntax to define a JenkinsFile

• Declarative Pipeline: This type of syntax offers an easy way for the creation of pipelines. It contains a predefined hierarchy and offers users the ability to control all aspects of a pipeline execution in a simple, straightforward manner.
• Scripted Pipeline: This type of Jenkins pipeline runs on the Jenkins master using a lightweight executor. It uses few resources to translate the pipeline into atomic commands.

By default, Jenkins 1.x does not perform any security checks. But, you can manually change that by customizing access controls and configuring it as per one’s need.

Access control locks down access to the Jenkins UI Console and users may log in to get access via Passwords.

One more feature in Jenkins for security is the additional subsystems to prevent direct and indirect attacks on the system.

After downloading the Jenkins installation file for Windows, go to your CMD Terminal and run the following command:

jenkins.exe start

Note: These are basic Jenkins interview questions a candidate must know the answers to.

To create pipelines in Jenkins, you must have a Jenkins instance setup with the appropriate plugins:

• Jenkins 1.580.1 or later (Jenkins 2.0 is best)
• Core Pipeline Plugin

To create a simple pipeline, follow these steps:

• Click on New Item on Jenkins home, enter a name for Pipeline and click OK.
• Go to the Script text area of the config screen and enter your pipeline syntax.
• Check the Groovy Sandbox option below the Script text Area to increase efficiency
• Click Save
• To create the pipeline, click on Build Now
• Click on this and select Console Output to view the output

Poll SCM periodically polls the SCM to check whether the changes were made (i.e. new commits) and also builds the project if there are new commits pushed since the last updated build.