Branch discovery configuration in Jenkins - Mini Project: Build & Apply

Branch Discovery Configuration in Jenkins

📖 Scenario: You are setting up a Jenkins job to automatically find and build branches from a Git repository. This helps your team test code changes on different branches without manual setup.

🎯 Goal: Configure a Jenkins pipeline job to discover branches from a Git repository using the Branch Discovery strategy.

📋 What You'll Learn

Create a Jenkins pipeline job configuration with Git SCM

Add branch discovery trait to find branches

Set up a simple pipeline script to print the branch name

Print the discovered branch name as output

💡 Why This Matters

🌍 Real World

Teams use branch discovery in Jenkins to automatically build and test code changes on all branches, improving continuous integration workflows.

💼 Career

Understanding branch discovery is essential for DevOps engineers and Jenkins administrators to maintain efficient CI/CD pipelines.

1

Create initial Jenkins pipeline job configuration

Create a Jenkins pipeline job configuration with a scm block using git and set the url to 'https://github.com/example/repo.git'.

Jenkins

# Create a Jenkins pipeline job configuration with git SCM and URL
pipeline {
    agent any
    stages {
        stage('Setup') {
            steps {
                // Your code here
            }
        }
    }
}

Need a hint?

Use checkout with GitSCM and set the repository URL exactly as given.

2

Add branch discovery trait to configuration

Add a traits list inside checkout configuration with a BranchDiscoveryTrait to enable branch discovery.

Jenkins

pipeline {
    agent any
    stages {
        stage('Setup') {
            steps {
                checkout([
                    $class: 'GitSCM',
                    branches: [[name: '*/main']],
                    userRemoteConfigs: [[
                        url: 'https://github.com/example/repo.git',
                        // Your code here
                    ]]
                ])
            }
        }
    }
}

Need a hint?

Add traits: [[$class: 'BranchDiscoveryTrait']] to enable branch discovery.

3

Add pipeline script to print current branch name

Add a script step inside the Setup stage that prints the current branch name using env.BRANCH_NAME.

Jenkins

pipeline {
    agent any
    stages {
        stage('Setup') {
            steps {
                checkout([
                    $class: 'GitSCM',
                    branches: [[name: '*/main']],
                    userRemoteConfigs: [[
                        url: 'https://github.com/example/repo.git'
                    ]],
                    extensions: [],
                    traits: [[$class: 'BranchDiscoveryTrait']]
                ])
                // Add a script step to print the branch name
                // Your code here
            }
        }
    }
}

Need a hint?

Use script { echo("Current branch is: ${env.BRANCH_NAME}") } to print the branch name.

4

Print the discovered branch name as output

Add a print equivalent in Jenkins pipeline by using echo to display the message "Current branch is: " followed by the branch name stored in env.BRANCH_NAME.

Jenkins

pipeline {
    agent any
    stages {
        stage('Setup') {
            steps {
                checkout([
                    $class: 'GitSCM',
                    branches: [[name: '*/main']],
                    userRemoteConfigs: [[
                        url: 'https://github.com/example/repo.git'
                    ]],
                    extensions: [],
                    traits: [[$class: 'BranchDiscoveryTrait']]
                ])
                script {
                    // Your code here
                }
            }
        }
    }
}

Need a hint?

Use echo("Current branch is: ${env.BRANCH_NAME}") to print the branch name.