Environment variables access in Jenkins - Mini Project: Build & Apply

Accessing Environment Variables in Jenkins Pipeline

📖 Scenario: You are setting up a Jenkins pipeline to automate a build process. You need to access environment variables inside the pipeline script to customize the build steps.

🎯 Goal: Build a Jenkins pipeline script that accesses and prints specific environment variables.

📋 What You'll Learn

Create a Jenkins pipeline script with a pipeline block

Access the environment variable BUILD_NUMBER

Access the environment variable MY_VAR

Print both environment variables using echo steps

💡 Why This Matters

🌍 Real World

Jenkins pipelines often need environment variables to customize builds, pass secrets, or configure deployment settings.

💼 Career

Understanding environment variables in Jenkins is essential for DevOps engineers to automate and manage CI/CD pipelines effectively.

1

Create a basic Jenkins pipeline skeleton

Write a Jenkins pipeline script starting with a pipeline block and a agent any directive.

Jenkins

pipeline {
    agent any
    // Your code here
}

Need a hint?

Start by writing pipeline { and inside it add agent any to run on any available agent.

2

Add an environment block to define environment variables

Inside the pipeline block, add an environment block that defines a variable MY_VAR with the value hello.

Jenkins

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

Need a hint?

Use the environment block inside pipeline and define MY_VAR = 'hello'.

3

Access and print environment variables in a stage

Add a stage named 'Print Env' with a steps block that uses echo to print BUILD_NUMBER and MY_VAR environment variables using env.BUILD_NUMBER and env.MY_VAR.

Jenkins

pipeline {
    agent any
    environment {
        MY_VAR = 'hello'
    }
    // Your code here
}

Need a hint?

Inside stages, add a stage('Print Env') with steps that use echo to print env.BUILD_NUMBER and env.MY_VAR.

4

Print the environment variables output

Run the pipeline script and ensure the console output shows the lines Build number is: followed by the build number and My variable is: hello.

Jenkins

pipeline {
    agent any
    environment {
        MY_VAR = 'hello'
    }
    stages {
        stage('Print Env') {
            steps {
                // Your code here
            }
        }
    }
}

Need a hint?

Run the pipeline and check the console output for the expected lines.