Conditional deployment logic in Jenkins - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is conditional deployment logic in Jenkins?

It is a way to control when and how deployment steps run based on specific conditions, like branch name or build status.

beginner

How can you check the branch name in a Jenkins pipeline to decide deployment?

Use the environment variable 'BRANCH_NAME' inside a 'when' block to run deployment only on certain branches.

intermediate

What Jenkins pipeline syntax allows running steps only if the build is successful?

The 'post' section with 'success' condition or a 'when' block checking 'currentBuild.currentResult == "SUCCESS"'.

beginner

Explain the use of the 'when' directive in Jenkins pipelines.

The 'when' directive lets you specify conditions to decide if a stage should run, like checking branch, environment variables, or build results.

beginner

How do you implement a conditional deployment only on the 'main' branch in a declarative Jenkins pipeline?

Use a 'when { branch 'main' }' block inside the deployment stage to run it only when building the 'main' branch.

Which Jenkins pipeline directive is used to run a stage only on a specific branch?

A environment

B when

C post

D agent

The 'when' directive controls if a stage runs based on conditions like branch name.

How do you check if the build was successful before deploying in Jenkins pipeline?

A Use 'agent any'

B Use 'when { branch "main" }'

C Use 'environment { BUILD_STATUS = "SUCCESS" }'

D Use 'post { success { ... } }'

The 'post { success { ... } }' block runs steps only if the build succeeded.

What environment variable commonly holds the branch name in Jenkins pipelines?

A BRANCH_NAME

B BUILD_ID

C JOB_NAME

D DEPLOY_ENV

BRANCH_NAME contains the current branch being built.

Which of these is NOT a valid condition for the 'when' directive in Jenkins declarative pipelines?

A branch

B success

C agent

D environment

'agent' is used to specify where to run, not a condition for 'when'.

What happens if the 'when' condition in a Jenkins stage is false?

A The stage is skipped

B The pipeline pauses

C The pipeline fails

D The stage runs anyway

If 'when' condition is false, Jenkins skips that stage.

Describe how you would set up a Jenkins pipeline to deploy only when building the 'main' branch and the build is successful.

Think about combining branch check and build status in pipeline syntax.

Explain the purpose of conditional deployment logic in Jenkins and why it is useful.

Consider real-life situations where you only want to deploy safe and correct code.