Continuous Integration/Continuous Deployment (CI/CD) has shaped how we develop and deliver software. In this age of agile approaches and fast-paced development, CI/CD is the backbone ensuring code quality and speedy deployment. Today, we are going to walk you through setting up a CI/CD pipeline for a Spring Boot application using Jenkins. We will use other tools like Docker, Maven, and GitHub to make this process seamless and efficient.
Setting up the Spring Boot Application
Before we deep dive into pipeline creation, let’s first create our Spring Boot application. Spring Boot is an open-source Java-based framework that provides a simplified platform for developing standalone, production-grade Spring-based applications.
To create a Spring Boot application, we will use the Spring Initializer website. On the site, fill in the necessary details like the project metadata, the type of packaging you want (Maven or Gradle), and the Java version. You should also add dependencies that your application might require. Once you’re done, click on the “Generate” button and download the zip file. Extract the zip file and import the project into your favorite Java IDE.
Integrating Spring Boot with Maven
Now that we have our Spring Boot application, our next step is to use Maven for building it. Maven is a powerful project management tool that’s based on the project object model (POM). Maven can manage a project’s build, reporting, and documentation from a central piece of information.
In the root directory of your project, you will find a pom.xml file. This is your Project Object Model (POM) that Maven uses. By default, Spring Initializr configures the pom.xml file with the necessary dependencies and plugins. Therefore, you don’t need to add anything at this stage.
Next, you need to build your Spring Boot application. You can do this by running the mvn clean install command in the terminal from the root directory of your project. This command will create a runnable JAR file in the target directory.
Dockerizing the Spring Boot Application
The next step in our process is to create a Docker image of our application. Docker allows us to package our app along with all the dependencies into a standardized unit for software development known as a Docker container.
To dockerize our application, we will create a Dockerfile in the root directory of our project. This file will contain the commands required to build a Docker image.
Here’s an example of how your Dockerfile might look:
FROM openjdk:8-jdk-alpine
VOLUME /tmp
COPY target/my-app-1.0.0.jar app.jar
ENTRYPOINT ["java", "-jar", "/app.jar"]
Once you’ve created the Dockerfile, you can build your Docker image using the docker build . -t my-app command in the terminal from the root directory of your project.
Integrating with GitHub
After Docker, the next step is to set up a GitHub repository. GitHub is a code hosting platform for version control and collaboration. It allows you and others to work together on projects from anywhere.
Start by creating a new repository on GitHub. Then, initialize a Git repository in your project directory using the git init command. Add all the project files to the Git repository using git add . and commit the changes with git commit -m "Initial commit". Finally, link your local repository to the GitHub repository using git remote add origin [your-repository-url] and push the changes using git push -u origin master.
Setting up the Jenkins Pipeline
Finally, we reach the core component of our process – setting up a CI/CD pipeline using Jenkins. Jenkins is an open-source automation server that enables developers to build, test, and deploy their software.
First, install Jenkins on your machine. After installation, open Jenkins in your browser and create a new pipeline. In the pipeline configuration, select “Pipeline script from SCM” and provide your GitHub repository URL.
Next, you will have to create a Jenkinsfile in your project directory. This file describes the stages and steps of your pipeline. Here is a basic example:
pipeline {
agent any
stages {
stage('Build') {
steps {
sh 'mvn clean install'
}
}
stage('Docker Build') {
steps {
sh 'docker build . -t my-app'
}
}
}
}
This pipeline has two stages – ‘Build’ and ‘Docker Build’. The ‘Build’ stage runs the mvn clean install command to build the project, and the ‘Docker Build’ stage builds the Docker image.
After setting up the pipeline, Jenkins will automatically detect the Jenkinsfile in your GitHub repository and start building your pipeline. Whenever you push changes to the GitHub repository, Jenkins will automatically trigger the pipeline, running the build and Docker stages as specified.
Overall, creating a CI/CD pipeline for a Spring Boot application using Jenkins allows for efficient and streamlined software development and deployment. We’ve walked through creating a Spring Boot application, integrating it with Maven, dockerizing the application, linking it to a GitHub repository, and finally, setting up the Jenkins pipeline. This process, while complex, will surely enhance your software development practices and keep your applications up-to-date and ready for delivery at all times.
Deploying the Dockerized Application
After the pipeline has been set up, let’s take a look at how to deploy your Spring Boot application using the created Docker image. Deployment is the final stage of the development pipeline where the application is made available for end-users.
First, you need to push your Docker image to a Docker registry such as Docker Hub. The Docker registry is a place where you can store and distribute Docker images. To do this, you’ll need to create a Docker Hub account if you don’t have one already, then tag your Docker image with your Docker Hub username and image name using docker tag my-app:latest [username]/my-app:latest. Push the Docker image to Docker Hub using docker push [username]/my-app:latest.
Once your Docker image is in Docker Hub, it can be pulled and run on any machine with Docker installed. To deploy your application, pull the Docker image using docker pull [username]/my-app:latest and run the Docker container with docker run -p 8080:8080 [username]/my-app:latest. Your Spring Boot application is now running in a Docker container and can be accessed at localhost:8080 on your local machine.
In a real-world scenario, you might also want to deploy your application on a cloud platform like AWS, Google Cloud, or Azure. In that case, you can use Kubernetes, a container orchestration platform, to manage your Docker containers.
In this article, we have completed the process of creating a CI/CD pipeline for a Spring Boot application using Jenkins. We started by setting up a Spring Boot application and integrated it with Maven. We then created a Docker image of our application, set up a GitHub repository for our source code, and finally deployed our application using the Docker image.
The Dockerized Spring Boot application is now ready for access by end-users. By creating a Docker image and using a Jenkins pipeline, we have made the application highly portable and ensured that it can be accurately reproduced on any platform.
CI/CD pipelines provide a systematic and efficient way to manage the lifecycle of an application, from development to deployment. It ensures that the code is always in a deployable state and reduces the time it takes to get changes into production.
The use of Jenkins allows for a high degree of automation in this process, reducing the potential for human error and increasing the speed at which new features can be delivered to users. Docker containers make our application environment independent, enabling it to run seamlessly on any platform.
Through this process, we have seen how these tools and practices can greatly improve the quality of software and the speed of its delivery. We hope this guide has been helpful to you in setting up a CI/CD pipeline for your own Spring Boot applications.
