Poll SCM configuration in Jenkins - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is Poll SCM in Jenkins?

Poll SCM is a Jenkins feature that checks the source code repository at regular intervals to see if there are any changes. If changes are found, it triggers a build.

beginner

How do you configure Poll SCM in a Jenkins job?

In the job configuration, under 'Build Triggers', select 'Poll SCM' and enter a schedule using cron syntax to specify how often Jenkins should check for changes.

intermediate

What does the cron syntax in Poll SCM schedule represent?

The cron syntax defines the timing for polling. It has five fields: minute, hour, day of month, month, and day of week. For example, 'H/15 * * * *' means every 15 minutes.

beginner

What happens if Poll SCM finds no changes in the repository?

If no changes are detected, Jenkins does not trigger a build. It simply waits until the next scheduled poll.

intermediate

Can Poll SCM trigger builds immediately after a commit?

No, Poll SCM triggers builds only at scheduled intervals. For immediate builds after commits, use webhooks or other trigger methods.

What does Poll SCM do in Jenkins?

A Deploys the application to production

B Automatically merges code branches

C Checks the source code repository for changes at set intervals

D Runs unit tests only

Poll SCM regularly checks the source code repository for changes and triggers builds if changes are found.

Where do you enable Poll SCM in Jenkins job configuration?

A Under 'Source Code Management'

B Under 'Build Triggers'

C Under 'Post-build Actions'

D Under 'Build Environment'

Poll SCM is enabled under the 'Build Triggers' section in Jenkins job configuration.

What does the cron expression 'H/10 * * * *' mean in Poll SCM?

A Poll every 10 minutes

B Poll every hour

C Poll once a day

D Poll every 10 seconds

The expression 'H/10 * * * *' means Jenkins polls the repository every 10 minutes.

If no changes are found during Poll SCM, what happens?

A Build is triggered anyway

B Jenkins restarts

C Jenkins sends an error

D No build is triggered

Jenkins only triggers a build if changes are detected during Poll SCM.

Which method triggers builds immediately after a commit instead of Poll SCM?

A Webhooks

B Manual build

C Scheduled build

D Polling every hour

Webhooks notify Jenkins immediately after a commit to trigger builds without waiting for polling.

Explain how Poll SCM works in Jenkins and how to configure it.

Think about how Jenkins checks for code changes regularly.

Describe the difference between Poll SCM and webhook triggers in Jenkins.

Consider timing and how builds start after code changes.