Jenkins Jenkins Administration

Question 1

Where does Jenkins store its configuration, jobs, and plugins by default on a Linux system?

Accepted Answer

/var/lib/jenkins

Answer

The default Jenkins home directory on Linux is `/var/lib/jenkins`, controlled by the `JENKINS_HOME` environment variable.

Question 2

What is the recommended way to apply Jenkins system configuration as code rather than through the UI?

Accepted Answer

Jenkins Configuration as Code (JCasC) Plugin

Answer

The Jenkins Configuration as Code (JCasC) plugin allows the entire Jenkins system configuration to be defined in a YAML file.

Question 3

Which file in JENKINS_HOME contains the main Jenkins system configuration?

Accepted Answer

config.xml

Answer

The `config.xml` file at the root of `JENKINS_HOME` stores the primary Jenkins system configuration in XML format.

Question 4

How do you safely restart Jenkins without losing queued builds?

Accepted Answer

Use /safeRestart endpoint or Manage Jenkins > Reload Configuration

Answer

The `/safeRestart` URL waits for all running builds to finish before restarting Jenkins, preventing build loss.

Question 5

What is the purpose of the Jenkins CLI tool (`jenkins-cli.jar`)?

Accepted Answer

Perform administrative tasks via command line without a browser

Answer

The Jenkins CLI jar allows administrators to trigger builds, manage jobs, and run Groovy scripts from the command line.

Jenkins Practice Test