Pushing images to registry in Jenkins - Mini Project: Build & Apply

Pushing images to registry

📖 Scenario: You are working as a DevOps engineer. Your team uses Jenkins to automate building and pushing Docker images to a container registry. You want to create a simple Jenkins pipeline script that builds a Docker image from a Dockerfile and pushes it to a registry.

🎯 Goal: Build a Jenkins pipeline script that builds a Docker image named myapp with tag v1 and pushes it to the Docker registry at docker.io/myuser/myapp:v1.

📋 What You'll Learn

Create a variable for the Docker image name

Create a variable for the Docker image tag

Use the docker.build command to build the image

Use the docker.withRegistry block to push the image

Print a message after pushing the image

💡 Why This Matters

🌍 Real World

Automating Docker image builds and pushes is common in continuous integration pipelines to ensure consistent deployments.

💼 Career

DevOps engineers and automation specialists use Jenkins pipelines to manage container images and deploy applications efficiently.

1

Set Docker image name and tag

Create two variables in the Jenkins pipeline script: imageName set to myapp and imageTag set to v1.

Jenkins

# Create variables imageName and imageTag
# Your code here

Need a hint?

Use def to declare variables in Jenkins scripted pipeline.

2

Build the Docker image

Use the docker.build command to build the Docker image with the name "${imageName}:${imageTag}" and assign it to a variable called appImage.

Jenkins

def imageName = 'myapp'
def imageTag = 'v1'
# Build the Docker image and assign to appImage
# Your code here

Need a hint?

Use docker.build with the image name and tag inside double quotes and curly braces.

3

Push the Docker image to registry

Use docker.withRegistry with the URL 'https://docker.io' and credentials ID 'dockerhub-creds' to push the image stored in appImage.

Jenkins

def imageName = 'myapp'
def imageTag = 'v1'
def appImage = docker.build("${imageName}:${imageTag}")
# Push the image to Docker registry
# Your code here

Need a hint?

Wrap the push command inside docker.withRegistry block with the registry URL and credentials ID.

4

Print confirmation message

Add a println statement to print "Docker image pushed: myapp:v1" after the image is pushed.

Jenkins

def imageName = 'myapp'
def imageTag = 'v1'
def appImage = docker.build("${imageName}:${imageTag}")
docker.withRegistry('https://docker.io', 'dockerhub-creds') {
    appImage.push()
}
# Print confirmation message
# Your code here

Need a hint?

Use println with the exact message including image name and tag.