Loading libraries in Jenkinsfile - Mini Project: Build & Apply

Loading Libraries in Jenkinsfile

📖 Scenario: You are setting up a Jenkins pipeline to automate your software build process. To keep your Jenkinsfile clean and reusable, you want to load a shared library that contains common functions.

🎯 Goal: Learn how to load a shared library in a Jenkinsfile and use a function from that library in your pipeline.

📋 What You'll Learn

Create a Jenkinsfile with a pipeline block

Load a shared library named my-shared-lib

Call a function greet from the shared library

Print the greeting message in the pipeline

💡 Why This Matters

🌍 Real World

Shared libraries in Jenkins help teams reuse common code like utility functions, reducing duplication and errors.

💼 Career

Knowing how to load and use shared libraries is essential for Jenkins pipeline developers and DevOps engineers to build maintainable CI/CD pipelines.

1

Create a basic Jenkins pipeline

Write a Jenkinsfile that defines a pipeline block with an empty stages section.

Jenkins

pipeline {
    agent any
    stages {
        // Your code here
    }
}

Need a hint?

Start with the basic Jenkins pipeline syntax including pipeline, agent any, and an empty stages block.

2

Load the shared library

Inside the pipeline block but before stages, add a libraries block that loads the shared library named my-shared-lib using lib('my-shared-lib').

Jenkins

pipeline {
    agent any
    libraries {
        lib('my-shared-lib')
    }
    stages {
        // Your code here
    }
}

Need a hint?

Use the libraries directive with lib('my-shared-lib') to load the shared library before the stages block.

3

Call the greet function from the library

Inside the stages block, add a stage named Greet with a steps section that calls the greet() function and stores its result in a variable called message.

Jenkins

pipeline {
    agent any
    libraries {
        lib('my-shared-lib')
    }
    stages {
        stage('Greet') {
            steps {
                // Your code here
            }
        }
    }
}

Need a hint?

Use a stage with steps and a script block to call greet() and assign it to message.

4

Print the greeting message

Inside the script block of the Greet stage, add a println statement to print the message variable.

Jenkins

pipeline {
    agent any
    libraries {
        lib('my-shared-lib')
    }
    stages {
        stage('Greet') {
            steps {
                script {
                    def message = greet()
                    // Your code here
                }
            }
        }
    }
}

Need a hint?

Use println(message) to print the greeting message returned by greet().