Script blocks for Groovy in Jenkins - Mini Project: Build & Apply

Script blocks for Groovy in Jenkins

📖 Scenario: You are automating a Jenkins pipeline. You want to use Groovy script blocks to run custom code inside the pipeline.

🎯 Goal: Build a Jenkins pipeline script that uses Groovy script blocks to define variables, add configuration, and print output.

📋 What You'll Learn

Create a Groovy script block with a variable

Add a configuration variable inside the script block

Use a script block to run a loop

Print the final output from the script block

💡 Why This Matters

🌍 Real World

Jenkins pipelines often use Groovy <code>script</code> blocks to run custom code for build, test, and deployment automation.

💼 Career

Knowing how to write Groovy <code>script</code> blocks in Jenkins is essential for DevOps engineers and automation specialists to customize CI/CD pipelines.

1

Create a Groovy script block with a variable

Write a Jenkins pipeline script block that defines a variable called message with the value "Hello from Groovy".

Jenkins

pipeline {
    agent any
    stages {
        stage('Setup') {
            steps {
                script {
                    // Your code here
                }
            }
        }
    }
}

Need a hint?

Use def message = "Hello from Groovy" inside the script block.

2

Add a configuration variable inside the script block

Inside the existing script block, add a variable called count and set it to 3.

Jenkins

pipeline {
    agent any
    stages {
        stage('Setup') {
            steps {
                script {
                    def message = "Hello from Groovy"
                    // Your code here
                }
            }
        }
    }
}

Need a hint?

Define def count = 3 inside the script block.

3

Use a script block to run a loop

Inside the script block, write a for loop that runs from 1 to count and appends " Run " plus the loop number to a variable called result. Initialize result as an empty string before the loop.

Jenkins

pipeline {
    agent any
    stages {
        stage('Setup') {
            steps {
                script {
                    def message = "Hello from Groovy"
                    def count = 3
                    // Your code here
                }
            }
        }
    }
}

Need a hint?

Initialize result as an empty string, then use a for loop with i from 1 to count. Append to result inside the loop.

4

Print the final output from the script block

Add a println statement inside the script block to print the combined message: the message variable followed by the result variable.

Jenkins

pipeline {
    agent any
    stages {
        stage('Setup') {
            steps {
                script {
                    def message = "Hello from Groovy"
                    def count = 3
                    def result = ""
                    for (int i = 1; i <= count; i++) {
                        result += " Run ${i}"
                    }
                    // Your code here
                }
            }
        }
    }
}

Need a hint?

Use println(message + result) to print the combined string.