Building Docker images in pipeline in Jenkins - Mini Project: Build & Apply

Building Docker images in pipeline

📖 Scenario: You work in a team that uses Jenkins to automate software builds. Your task is to create a Jenkins pipeline script that builds a Docker image from a simple Dockerfile. This helps your team package applications consistently.

🎯 Goal: Build a Jenkins pipeline script that defines a Docker image build step using a Dockerfile in the project folder. The pipeline should build the image with a specific name.

📋 What You'll Learn

Create a Jenkins pipeline script with a pipeline block

Define an agent to run the pipeline on any available node

Add a stage named Build Docker Image

Inside the stage, run a shell command to build a Docker image named myapp:latest using the Dockerfile in the current directory

Print a message after the build completes

💡 Why This Matters

🌍 Real World

Teams use Jenkins pipelines to automate building Docker images for consistent application packaging and deployment.

💼 Career

Knowing how to write Jenkins pipelines that build Docker images is a key skill for DevOps engineers and automation specialists.

1

Create the Jenkins pipeline skeleton

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

Jenkins

pipeline {
    agent any
    // Your code here
}

Need a hint?

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

2

Add a stage to build the Docker image

Inside the pipeline block, add a stages block with one stage named Build Docker Image.

Jenkins

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

Need a hint?

Add stages {} inside pipeline. Then add a stage('Build Docker Image') with steps {} inside.

3

Add the Docker build shell command

Inside the steps block of the Build Docker Image stage, add a sh step that runs docker build -t myapp:latest . to build the Docker image.

Jenkins

pipeline {
    agent any
    stages {
        stage('Build Docker Image') {
            steps {
                // Add shell command to build Docker image here
            }
        }
    }
}

Need a hint?

Use sh 'docker build -t myapp:latest .' inside steps to run the Docker build command.

4

Print a message after building the image

After the sh command inside the steps block, add a echo step that prints 'Docker image myapp:latest built successfully.'.

Jenkins

pipeline {
    agent any
    stages {
        stage('Build Docker Image') {
            steps {
                sh 'docker build -t myapp:latest .'
                // Add echo message here
            }
        }
    }
}

Need a hint?

Use echo 'Docker image myapp:latest built successfully.' after the shell command to print the message.