Jenkinsfile per branch - Mini Project: Build & Apply

Jenkinsfile per branch

📖 Scenario: You work in a team where each Git branch needs its own Jenkins pipeline configuration. This helps run different build steps depending on the branch.

🎯 Goal: Create a Jenkinsfile that runs different stages based on the current Git branch name.

📋 What You'll Learn

Create a variable to hold the current Git branch name

Create a variable to hold the build stage name based on the branch

Use a when condition to run a stage only on the main branch

Print the branch name and the selected build stage

💡 Why This Matters

🌍 Real World

Teams often need different build or test steps for different branches, like main, develop, or feature branches. This Jenkinsfile setup helps automate that.

💼 Career

Knowing how to customize Jenkins pipelines per branch is a key skill for DevOps engineers and CI/CD pipeline developers.

1

Get the current Git branch name

Create a variable called branchName that gets the current Git branch name using env.BRANCH_NAME.

Jenkins

# Your code here

Need a hint?

The current branch name is stored in env.BRANCH_NAME.

2

Set build stage name based on branch

Add a variable called buildStage in the environment section. Set it to "Build Main" if branchName is "main", otherwise set it to "Build Feature".

Jenkins

pipeline {
    agent any
    environment {
        branchName = env.BRANCH_NAME
        // Your code here
    }
}

Need a hint?

Use a ternary operator to set buildStage based on branchName.

3

Add a stage that runs only on main branch

Add a stage named Build Main that runs only when branchName is "main". Use the when directive with expression { branchName == 'main' }. Inside the stage, add a steps block with a echo command that prints "Building main branch".

Jenkins

pipeline {
    agent any
    environment {
        branchName = env.BRANCH_NAME
        buildStage = branchName == 'main' ? 'Build Main' : 'Build Feature'
    }
    stages {
        // Your code here
    }
}

Need a hint?

The when directive controls if a stage runs. Use expression { branchName == 'main' } to check the branch.

4

Print the branch and build stage

Add a stage named Print Info that runs on all branches. Inside steps, add two echo commands: one to print "Current branch: ${branchName}" and another to print "Selected build stage: ${buildStage}".

Jenkins

pipeline {
    agent any
    environment {
        branchName = env.BRANCH_NAME
        buildStage = branchName == 'main' ? 'Build Main' : 'Build Feature'
    }
    stages {
        stage('Build Main') {
            when {
                expression { branchName == 'main' }
            }
            steps {
                echo 'Building main branch'
            }
        }
        // Your code here
    }
}

Need a hint?

Use echo inside steps to print variables with ${} syntax.