Try-catch-finally in pipelines in Jenkins - Mini Project: Build & Apply

Try-catch-finally in Jenkins Pipelines

📖 Scenario: You are creating a Jenkins pipeline script to automate a simple build process. Sometimes the build step might fail, and you want to handle errors gracefully. You also want to always run a cleanup step at the end, no matter if the build succeeded or failed.

🎯 Goal: Build a Jenkins pipeline script that uses try, catch, and finally blocks to run a build step, handle any errors by printing a message, and always run a cleanup step.

📋 What You'll Learn

Create a pipeline block with agent any

Inside stages, create a stage named Build

Use try block to run a shell command sh 'exit 1' to simulate failure

Use catch block to catch errors and print Build failed

Use finally block to print Cleaning up

💡 Why This Matters

🌍 Real World

In real Jenkins pipelines, builds can fail due to many reasons. Using try-catch-finally helps keep the pipeline stable and ensures cleanup steps always run.

💼 Career

Understanding error handling in Jenkins pipelines is essential for DevOps engineers to create reliable automation scripts.

1

Create the basic Jenkins pipeline structure

Create a Jenkins pipeline with agent any and an empty stages block.

Jenkins

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

Need a hint?

Start by writing pipeline { agent any stages { } to set up the pipeline skeleton.

2

Add a Build stage with a try block

Inside stages, add a stage named Build with a steps block. Inside steps, add a script block containing a try block that runs sh 'exit 1' to simulate a failure.

Jenkins

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

Need a hint?

Use stage('Build') and inside steps add script { try { sh 'exit 1' } }.

3

Add catch and finally blocks

Inside the script block, after the try block, add a catch (err) block that prints Build failed using echo. Then add a finally block that prints Cleaning up using echo.

Jenkins

pipeline {
    agent any
    stages {
        stage('Build') {
            steps {
                script {
                    try {
                        sh 'exit 1'
                    }
                    // Your code here
                }
            }
        }
    }
}

Need a hint?

After try, add catch (err) { echo 'Build failed' } and finally { echo 'Cleaning up' }.

4

Print the final pipeline script output

Run the pipeline script and observe the output. The output should include Build failed and Cleaning up messages.

Jenkins

// Run the pipeline and check the console output

Need a hint?

Look at the Jenkins console output after running the pipeline. You should see both messages printed.