Build triggers (poll SCM, webhook, timer) in Jenkins - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a build trigger in Jenkins?

A build trigger is a way to start a Jenkins job automatically based on certain events or schedules, like code changes or time intervals.

beginner

How does 'Poll SCM' trigger work in Jenkins?

Poll SCM checks the source code repository at set intervals to see if there are changes. If changes are found, it starts a build.

intermediate

What is a webhook trigger in Jenkins?

A webhook trigger starts a Jenkins build immediately when the source code repository sends a notification about a change.

beginner

Explain the timer trigger in Jenkins.

A timer trigger starts a Jenkins build at scheduled times using cron syntax, regardless of code changes.

intermediate

Which build trigger is more efficient for immediate builds after code changes: Poll SCM or Webhook?

Webhook is more efficient because it starts the build immediately after a change, while Poll SCM waits for the next scheduled check.

What does the 'Poll SCM' trigger do in Jenkins?

A Starts a build immediately when code is pushed

B Checks the source code repository at intervals for changes

C Runs a build at a fixed time every day

D Manually triggers a build

'Poll SCM' checks the repository regularly and triggers a build if changes are detected.

Which trigger uses cron syntax to schedule builds?

A Timer

B Webhook

C Poll SCM

D Manual

The Timer trigger uses cron syntax to schedule builds at specific times.

What is the main advantage of using a webhook trigger?

A It triggers builds immediately after code changes

B It polls the repository every minute

C It schedules builds at night

D It reduces build frequency

Webhook triggers start builds right after code changes, making builds faster and more efficient.

If you want Jenkins to build every hour regardless of code changes, which trigger should you use?

A Poll SCM

B Webhook

C Manual

D Timer

Timer trigger schedules builds at fixed times, like every hour, independent of code changes.

Which trigger requires the source code repository to support sending notifications?

A Timer

B Poll SCM

C Webhook

D Manual

Webhook triggers depend on the repository sending notifications to Jenkins.

Describe the differences between Poll SCM, Webhook, and Timer triggers in Jenkins.

Think about how and when each trigger starts a build.

Explain why you might choose a webhook trigger over polling SCM in a Jenkins pipeline.

Consider build speed and system load.