Jenkins Cheat Sheet 2026

The 30 highest-yield Jenkins facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. Which permission allows a user to read job configurations but not modify them in Jenkins Matrix security? → Job/Read
2. What is the purpose of the `stages` block in a Declarative Pipeline? → To contain one or more stage blocks that represent pipeline phases
3. Which file contains the main Jenkins configuration settings? → config.xml
4. Jenkins was created by → Kohsuke Kawaguchi
5. What does the `cleanWs()` step do in a Jenkins Pipeline? → Cleans (deletes) the current workspace on the agent before or after a build
6. In Jenkins, what does setting a job's 'Build Periodically' trigger to 'H H(6-8) * * 1-5' mean? → Build once per day, sometime between 6 AM and 8 AM, only on weekdays
7. Jenkins supports which of the following SCM tools? → All of the above
8. What environment variable is automatically set by Jenkins to identify the agent name where a build runs? → NODE_NAME
9. What is the purpose of the Jenkins CLI tool (`jenkins-cli.jar`)? → Perform administrative tasks via command line without a browser
10. Which agent connection method allows Jenkins to initiate the connection to the agent via SSH? → SSH Build Agents (Launch via SSH)
11. Which Jenkins feature allows you to deploy to different environments (dev, staging, prod) using the same pipeline? → Parameterized builds with environment parameters
12. What does `withCredentials` block do in a Jenkins Pipeline? → Binds stored credentials to environment variables for use within its block
13. What is an upstream/downstream job relationship in Jenkins? → An upstream job triggers a downstream job upon completion, creating a build chain
14. What Jenkins Pipeline trigger syntax polls the SCM every 10 minutes? → pollSCM('H/10 * * * *')
15. In a Declarative Pipeline, what block wraps the entire pipeline definition? → pipeline {}
16. What happens to an agent's workspace after a build completes by default? → It persists on the agent filesystem for the next build of the same job
17. Where is Jenkins security configuration managed? → Manage Jenkins > Configure Global Security
18. Which of the following is the best approach to Devops security? → All of the above
19. What is a Jenkins agent (formerly called slave)? → A machine that connects to the Jenkins controller to run build jobs
20. What is the effect of setting 'Number of Executors' to 4 on a Jenkins agent? → The agent can run up to 4 build jobs simultaneously
21. What is the purpose of `input` step in a Jenkins Pipeline? → To pause the pipeline and wait for human approval before continuing
22. What does `sh` step do in a Jenkins Pipeline? → Runs a shell command on the agent
23. Which trigger type in Jenkins allows builds to be queued when an upstream job is UNSTABLE in addition to successful? → Build after other projects are built (with 'Trigger even if the build is unstable' option)
24. Which Jenkins plugin enables triggering builds based on file system changes rather than SCM commits? → FSTrigger Plugin
25. How do you define a parallel execution of stages in a Declarative Pipeline? → Use parallel {} inside a stage block
26. What is the purpose of the 'Build Triggers' section in a Jenkins job configuration? → To define what events or schedules should automatically start a build
27. How does Jenkins handle the first-time setup unlock screen? → Requires a one-time password from the server file system to proceed
28. Which file in JENKINS_HOME contains the main Jenkins system configuration? → config.xml
29. How do you prevent a Jenkins job from showing up in search results or the dashboard? → Use a View to filter jobs
30. Which Jenkins feature allows auditing who changed a job's configuration and when? → Audit Trail Plugin