Most Asked DevOps Interview Questions

121. How do I add delay in Jenkins?

There is a "quiet period" option in jenkins. You can set a value of 120(it’s in seconds) to delay the job by 2 minutes in starting.

122. What is the difference between Web server & Application server?

Web server mainly deals with the http requests and serves static content like static html web pages, images , javascript, etc. Caching static content, load balancing and clustering can be done in the web server.
Application server receives requests from web-server to serve dynamic content like Search results, business logic of the application. Application server is the one who interacts with databases and provides content to the web users.

123. How do you deploy an application in Tomcat?

1. Firstly we should build a war-file/artifact.
2. And Jenkins will trigger a shell script for deployment.
3. It checks if the tomcat/target machine is running & has enough disk space.
4. Jenkins will copy the war files into tomcat’s webapps location.

124. How to clone a GIT Repository via Jenkins?

Create a Jenkins Job to clone you a Git repository, go to configure and set git repository’s URL, Save and Build the Job, that clones you a Git repository.

125. How to set up a Jenkins Job?

1. Log in to Jenkins.
2. Click "New Item."
3. Enter a job name and select the job type (e.g., Freestyle, Pipeline).
4. Configure job settings like source code management and build steps.
5. Save the job configuration.
6. Trigger a build to test your setup.

126. Explain how to move or copy Jenkins jobs from one server to another?

It is very simple to move or copy jenkins jobs from one machine to another, just go through the following steps:
1. To copy a Jenkins job, copy an existing job and paste it in another machine’s Jenkins jobs location.
2. You can move a job from one Jenkins server to another by simply moving the particular job directory and paste it in Jenkins Jobs location of another machine.

127. What is a parameterized job in Jenkins?

For a single job/project you can have multiple configurations and while triggering a job/project jenkins will ask you to provide any configuration to follow. For example you have created a job and configured it to deploy in all the environments, and you made it parameterized so that Jenkins will ask you to select a specific environment (like QA, UAT, Staging, Pre-Prod, etc..) before starting a Parameterized build.

128. How to Create a backup and copy files in Jenkins?

To create a backup of Jenkins Job, just copy %Jobs_name% directory, you can also copy a Jobs directory to all your jobs. Here you may miss some configuration files. So the best way is to copy .jenkins directory.
To create a Jenkins backup, all you need to do is to periodically copy your %JENKINS_HOME% (.jenkins) directory. It contains all of your builds, jobs configurations, your build history and everything.

129. Explain how you deploy a custom build of a core plugin?

The hpi package is the custom format Jenkins uses to distribute plugins. Here are the steps to deploy custom build of a core plugin:
1. Stop jenkins.
2. Copy your custom HPI package to $JENKINS_HOME/plugins.
3. Remove the previous expanded plugin directory.
4. Make an empty file called .hpi. And start jenkins.

130. What are the various ways to schedule builds in jenkins?

Yes, Jenkins has an options to schedule a builds:
  1 By Source code management commits using Poll SCM.
  2 After completion of other builds using post build condition.
  3 Can be scheduled to run at a specified time using the build periodically option.
  4 And there is one more option called Delay.