Milestone step for concurrency in Jenkins - Mini Project: Build & Apply

Using Milestone Step for Concurrency Control in Jenkins Pipelines

📖 Scenario: You are managing a Jenkins pipeline that deploys applications. Sometimes multiple builds run at the same time, but you want to make sure only the latest build proceeds past a certain point to avoid conflicts.

🎯 Goal: Build a Jenkins pipeline script that uses the milestone step to control concurrency, allowing only the newest build to continue past the milestone.

📋 What You'll Learn

Create a Jenkins pipeline script with a milestone step

Add a stage before the milestone to simulate build preparation

Add a stage after the milestone to simulate deployment

Use the milestone step with an explicit ordinal number

Print messages to show the pipeline progress

💡 Why This Matters

🌍 Real World

In real Jenkins pipelines, the milestone step helps prevent multiple builds from deploying at the same time, avoiding conflicts and wasted resources.

💼 Career

Understanding concurrency control in Jenkins pipelines is important for DevOps engineers to maintain stable and efficient CI/CD workflows.

1

Create the initial Jenkins pipeline with a preparation stage

Write a Jenkins pipeline script that defines a pipeline block with an agent any and a stage named 'Preparation'. Inside this stage, add a steps block that prints 'Starting build preparation'.

Jenkins

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

Need a hint?

Use echo inside steps to print the message.

2

Add a milestone step with ordinal 1 after preparation

Add a new stage named 'Milestone' after the 'Preparation' stage. Inside its steps block, add a milestone 1 step to mark the concurrency control point.

Jenkins

pipeline {
    agent any
    stages {
        stage('Preparation') {
            steps {
                echo 'Starting build preparation'
            }
        }
        stage('Milestone') {
            steps {
                // Your code here
            }
        }
    }
}

Need a hint?

The milestone step takes an integer ordinal to identify the milestone.

3

Add a deployment stage after the milestone

Add a stage named 'Deploy' after the 'Milestone' stage. Inside its steps block, add an echo statement that prints 'Deploying application'.

Jenkins

pipeline {
    agent any
    stages {
        stage('Preparation') {
            steps {
                echo 'Starting build preparation'
            }
        }
        stage('Milestone') {
            steps {
                milestone 1
            }
        }
        stage('Deploy') {
            steps {
                // Your code here
            }
        }
    }
}

Need a hint?

Use echo to print the deployment message inside the Deploy stage.

4

Print a final message after deployment

Add a post block to the pipeline with a always condition. Inside it, add a script block that prints 'Pipeline finished' using echo.

Jenkins

pipeline {
    agent any
    stages {
        stage('Preparation') {
            steps {
                echo 'Starting build preparation'
            }
        }
        stage('Milestone') {
            steps {
                milestone 1
            }
        }
        stage('Deploy') {
            steps {
                echo 'Deploying application'
            }
        }
    }
    // Your code here
}

Need a hint?

The post block runs after all stages. Use always to run regardless of success or failure.