CJE Readiness Exam —Q&A
CJE READINESS EXAM
Questions and Answers| Latest Update
Certified Jenkins Engineer (CJE) Certification
Covers: Jenkins Architecture • Jobs & Views • Declarative & Scripted Pipelines
Distributed Builds • SCM Integration • Plugins • Security & Credentials
Notifications & Artifacts • Shared Libraries & Best Practices
Page 1
, CJE Readiness Exam —Q&A
Q1. What is Jenkins primarily used for?
A. Version control
B. Continuous Integration and Continuous Delivery (CI/CD)
C. Cloud storage
D. Database management
Answer: B. Continuous Integration and Continuous Delivery (CI/CD)
Rationale: Jenkins is an open-source automation server whose core purpose is
to automate the building, testing, and deployment of software as part of
CI/CD pipelines.
Q2. Which directory is commonly referred to as the 'Jenkins Home' directory?
A. /etc/jenkins
B. JENKINS_HOME
C. /var/lib/java
D. /opt/jenkins/bin
Answer: B. JENKINS_HOME
Rationale: JENKINS_HOME is the environment variable/directory that stores
all Jenkins configuration, job definitions, plugins, and build history.
Q3. Jenkins is written primarily in which programming language?
A. Python
B. Java
C. Ruby
D. Go
Answer: B. Java
Rationale: Jenkins is a Java-based application and runs inside a Java Virtual
Machine (JVM), often via an embedded or standalone servlet container.
Q4. Which default port does the Jenkins web interface run on after a standard
installation?
A. 80
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, CJE Readiness Exam —Q&A
B. 443
C. 8080
D. 3000
Answer: C. 8080
Rationale: Jenkins ships with a default HTTP port of 8080 for its web UI,
configurable via the --httpPort startup argument or JENKINS_PORT.
Q5. Which file typically holds the initial administrator password after a fresh
Jenkins install?
A. initialAdminPassword
B. secrets.key
C. config.xml
D. credentials.xml
Answer: A. initialAdminPassword
Rationale: During setup, Jenkins writes a randomly generated password to
$JENKINS_HOME/secrets/initialAdminPassword, required to unlock the
instance the first time.
Q6. Which of the following is NOT a valid way to install Jenkins?
A. WAR file execution with java -jar
B. Docker container
C. Native OS packages (apt/yum)
D. Installing it as a browser extension
Answer: D. Installing it as a browser extension
Rationale: Jenkins is a server application, not a browser extension; it is
installed via WAR file, Docker image, OS packages, or cloud marketplace
images.
Q7. What is the purpose of the Jenkins 'controller' (formerly called 'master')?
A. To execute all build steps exclusively
B. To schedule jobs, dispatch builds to agents, and serve the web UI
C. To store source code permanently
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, CJE Readiness Exam —Q&A
D. To act only as a load balancer
Answer: B. To schedule jobs, dispatch builds to agents, and serve the web
UI
Rationale: The controller is the central coordinating server that manages job
configuration, scheduling, the UI, and delegates actual build execution to
agents.
Q8. Which command-line tool lets you interact with Jenkins remotely via scripts?
A. jenkins-cli.jar
B. jkctl
C. jenkinsctl
D. jbuild
Answer: A. jenkins-cli.jar
Rationale: jenkins-cli.jar is the official Jenkins CLI client that allows remote
command execution such as creating jobs or managing the queue.
Q9. Where does Jenkins store plugin .hpi/.jpi files by default?
A. $JENKINS_HOME/plugins
B. $JENKINS_HOME/war
C. /usr/share/java
D. $JENKINS_HOME/jobs
Answer: A. $JENKINS_HOME/plugins
Rationale: Installed plugins and their metadata reside in the plugins
subdirectory of JENKINS_HOME.
Q10. What is true about Java version requirements when installing modern
Jenkins (LTS) releases?
A. Jenkins requires a specific supported Java version per LTS release and may
fail to start on unsupported/older JVMs
B. Jenkins runs on any Java version without restriction
C. Jenkins does not require Java at all
D. Jenkins only supports Java 6
Page 4
CJE READINESS EXAM
Questions and Answers| Latest Update
Certified Jenkins Engineer (CJE) Certification
Covers: Jenkins Architecture • Jobs & Views • Declarative & Scripted Pipelines
Distributed Builds • SCM Integration • Plugins • Security & Credentials
Notifications & Artifacts • Shared Libraries & Best Practices
Page 1
, CJE Readiness Exam —Q&A
Q1. What is Jenkins primarily used for?
A. Version control
B. Continuous Integration and Continuous Delivery (CI/CD)
C. Cloud storage
D. Database management
Answer: B. Continuous Integration and Continuous Delivery (CI/CD)
Rationale: Jenkins is an open-source automation server whose core purpose is
to automate the building, testing, and deployment of software as part of
CI/CD pipelines.
Q2. Which directory is commonly referred to as the 'Jenkins Home' directory?
A. /etc/jenkins
B. JENKINS_HOME
C. /var/lib/java
D. /opt/jenkins/bin
Answer: B. JENKINS_HOME
Rationale: JENKINS_HOME is the environment variable/directory that stores
all Jenkins configuration, job definitions, plugins, and build history.
Q3. Jenkins is written primarily in which programming language?
A. Python
B. Java
C. Ruby
D. Go
Answer: B. Java
Rationale: Jenkins is a Java-based application and runs inside a Java Virtual
Machine (JVM), often via an embedded or standalone servlet container.
Q4. Which default port does the Jenkins web interface run on after a standard
installation?
A. 80
Page 2
, CJE Readiness Exam —Q&A
B. 443
C. 8080
D. 3000
Answer: C. 8080
Rationale: Jenkins ships with a default HTTP port of 8080 for its web UI,
configurable via the --httpPort startup argument or JENKINS_PORT.
Q5. Which file typically holds the initial administrator password after a fresh
Jenkins install?
A. initialAdminPassword
B. secrets.key
C. config.xml
D. credentials.xml
Answer: A. initialAdminPassword
Rationale: During setup, Jenkins writes a randomly generated password to
$JENKINS_HOME/secrets/initialAdminPassword, required to unlock the
instance the first time.
Q6. Which of the following is NOT a valid way to install Jenkins?
A. WAR file execution with java -jar
B. Docker container
C. Native OS packages (apt/yum)
D. Installing it as a browser extension
Answer: D. Installing it as a browser extension
Rationale: Jenkins is a server application, not a browser extension; it is
installed via WAR file, Docker image, OS packages, or cloud marketplace
images.
Q7. What is the purpose of the Jenkins 'controller' (formerly called 'master')?
A. To execute all build steps exclusively
B. To schedule jobs, dispatch builds to agents, and serve the web UI
C. To store source code permanently
Page 3
, CJE Readiness Exam —Q&A
D. To act only as a load balancer
Answer: B. To schedule jobs, dispatch builds to agents, and serve the web
UI
Rationale: The controller is the central coordinating server that manages job
configuration, scheduling, the UI, and delegates actual build execution to
agents.
Q8. Which command-line tool lets you interact with Jenkins remotely via scripts?
A. jenkins-cli.jar
B. jkctl
C. jenkinsctl
D. jbuild
Answer: A. jenkins-cli.jar
Rationale: jenkins-cli.jar is the official Jenkins CLI client that allows remote
command execution such as creating jobs or managing the queue.
Q9. Where does Jenkins store plugin .hpi/.jpi files by default?
A. $JENKINS_HOME/plugins
B. $JENKINS_HOME/war
C. /usr/share/java
D. $JENKINS_HOME/jobs
Answer: A. $JENKINS_HOME/plugins
Rationale: Installed plugins and their metadata reside in the plugins
subdirectory of JENKINS_HOME.
Q10. What is true about Java version requirements when installing modern
Jenkins (LTS) releases?
A. Jenkins requires a specific supported Java version per LTS release and may
fail to start on unsupported/older JVMs
B. Jenkins runs on any Java version without restriction
C. Jenkins does not require Java at all
D. Jenkins only supports Java 6
Page 4
