Enterprise Java

Eclipse JKube

JKube is a versatile Kubernetes-native Java development tool, that streamlines containerization and deployment processes. With JKube, developers can seamlessly build, package, and deploy Java applications on Kubernetes clusters. It supports various build tools like Maven and Gradle, enabling effortless configuration and resource management. Its powerful plugins automate tasks such as Docker image creation, Kubernetes manifests generation, and Helm chart packaging.

Eclipse JKube ensures smooth integration with popular IDEs, simplifying the development lifecycle. Whether you’re a beginner or an experienced developer, JKube’s user-friendly interface and extensive documentation make it an essential tool for Java developers aiming for seamless Kubernetes deployments.

1. What is JKube?

JKube is a powerful tool tailored for Java developers, aiming to simplify the complexities of deploying Java applications on Kubernetes clusters. It automates various processes, streamlining containerization, and ensuring hassle-free deployment. Below, we explore its features, and use cases, along with its pros and cons.

1.1 Features

  • Kubernetes-Native: JKube seamlessly integrates with Kubernetes, ensuring applications are optimized for the containerized environment.
  • Build Tool Support: It supports popular build tools like Maven and Gradle, enabling developers to manage dependencies effortlessly.
  • Automated Tasks: JKube automates essential tasks such as Docker image creation, Kubernetes manifest generation, and Helm chart packaging.
  • IDE Integration: It offers smooth integration with various Integrated Development Environments (IDEs), enhancing developer productivity.
  • Resource Management: Developers can manage Kubernetes resources efficiently, defining configurations and settings with ease.

1.2 Use Cases

JKube finds applications in diverse scenarios within the software development lifecycle –

  • Microservices Deployment: Simplifies the deployment of Java-based microservices on Kubernetes clusters.
  • Continuous Integration/Continuous Deployment (CI/CD): Integrates seamlessly into CI/CD pipelines, automating the deployment process.
  • Cloud-Native Applications: Facilitates the development and deployment of cloud-native Java applications, ensuring scalability and reliability.

1.3 Pros

  • Efficiency: Streamlines the deployment process, saving time and effort for developers.
  • Integration: Integrates well with existing development workflows and tools.
  • Automation: Automates repetitive tasks, reducing the likelihood of human errors.
  • Community Support: Benefits from an active community, ensuring continuous improvement and support.

1.4 Cons

  • Learning Curve: Beginners might find it challenging initially due to the intricate nature of Kubernetes.
  • Customization: Advanced customization might require a deep understanding of Kubernetes concepts.
  • Dependency: Relies on the stability and features of the underlying Kubernetes platform.

2. A Beginner’s Guide

Integrating JKube into your Java projects with Maven or Gradle is a straightforward process. Here’s a step-by-step guide on how to get started. Ensure that you have a running Kubernetes cluster and appropriate credentials configured (found in your ~/.kube/config file) for JKube to connect to the cluster.

For brevity, I am focusing only on the Maven plugin with a k8 environment.

2.1 Using Maven

Add JKube Plugin to Your pom.xml file.


<version>1.0.1</version> <!-- Use the latest version -->

2.2 Configure Your Kubernetes Resources

Create Kubernetes resource files (e.g., deployment.yaml, service.yaml) in the src/main/jkube directory.

2.3 Build and Deploy

Run the following Maven command to build your project, generate a Docker image, and deploy it to Kubernetes.

Build and Deploy

mvn clean package k8s:build k8s:resource k8s:apply
  • mvn clean: Cleans the project by deleting the target directory.
  • package: Compiles the source code, runs tests and packages the application into a JAR file.
  • k8s:build: Builds the Docker image for the application.
  • k8s:resource: Generates Kubernetes resource descriptors based on the configuration files.
  • k8s:apply: Deploys the application to a Kubernetes cluster.

2.3.1 Ide Output

Console output for the command –

Ide output

[INFO] Scanning for projects...
[INFO] ------------------------------------------------------------------------
[INFO] Building Your Java Application
[INFO] ------------------------------------------------------------------------
[INFO] --- maven-clean-plugin:3.1.0:clean (default-clean) @ your-java-app ---
[INFO] Deleting /path/to/your-java-app/target
[INFO] --- maven-resources-plugin:3.2.0:resources (default-resources) @ your-java-app ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Copying 2 resources
[INFO] --- maven-compiler-plugin:3.8.1:compile (default-compile) @ your-java-app ---
[INFO] Nothing to compile - all classes are up to date
[INFO] --- maven-resources-plugin:3.2.0:testResources (default-testResources) @ your-java-app ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory /path/to/your-java-app/src/test/resources
[INFO] --- maven-compiler-plugin:3.8.1:testCompile (default-testCompile) @ your-java-app ---
[INFO] Nothing to compile - all classes are up to date
[INFO] --- maven-surefire-plugin:2.22.2:test (default-test) @ your-java-app ---
[INFO] No tests to run.
[INFO] --- maven-jar-plugin:3.1.0:jar (default-jar) @ your-java-app ---
[INFO] Building jar: /path/to/your-java-app/target/your-java-app.jar
[INFO] --- docker-maven-plugin:0.33.0:build (default-cli) @ your-java-app ---
[INFO] Building image your-docker-registry/your-java-app:latest
[INFO] Successfully built and tagged your-docker-registry/your-java-app:latest
[INFO] --- k8s-maven-plugin:1.0.1:resource (default-cli) @ your-java-app ---
[INFO] Filling Kubernetes namespace with resources from /path/to/your-java-app/target/classes/META-INF/jkube/kubernetes.yml
[INFO] --- k8s-maven-plugin:1.0.1:apply (default-cli) @ your-java-app ---
[INFO] k8s: Applying resources in Kubernetes namespace your-namespace
[INFO] k8s: namespace 'your-namespace' has been created
[INFO] k8s: service 'your-service' has been created
[INFO] k8s: Applying Service your-service
[INFO] k8s: Applying Deployment your-deployment
[INFO] k8s: service 'your-service' has been created
[INFO] k8s: Applying Service your-service
[INFO] k8s: Applying Deployment your-deployment
[INFO] k8s: Waiting for your-deployment to become ready
[INFO] ------------------------------------------------------------------------
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  10.659 s
[INFO] Finished at: 2023-10-10T14:30:01+00:00
[INFO] ------------------------------------------------------------------------

For security reasons, the actual path of the application is replaced with /path/to/your-java-app.

2.4 Additional Features

JKube offers a variety of powerful tools and functionalities beyond basic deployment. Let’s briefly explore some of these advanced features:

  • Logging: JKube allows developers to access logs directly from deployed pods. This feature is invaluable for monitoring applications in real time, aiding in debugging and issue resolution.
    mvn k8s:log
  • Debugging: Debugging Java applications running in Kubernetes can be challenging. JKube simplifies this process by enabling remote debugging. Developers can attach their IDE to running pods, allowing them to step through code and diagnose issues effectively.
    -- You can change the port number as per your implementation.
    mvn k8s:debug -Djkube.debug.port=4400
  • Watch Mode: JKube’s watch mode is a developer-friendly feature. It monitors local files for changes and automatically triggers redeployment. This means developers can focus on coding without worrying about the deployment process, making the development cycle faster and more efficient.
    mvn k8s:watch
  • Pushing Images: With JKube, developers can seamlessly push Docker images to container registries like Docker Hub or Google Container Registry. This feature is essential for sharing applications with teammates or deploying them in different environments.
    mvn k8s:push
  • Resource Configuration: JKube enables detailed configuration of Kubernetes resources through annotations and customization options. This flexibility ensures that applications are deployed with the appropriate resource limits, environment variables, and other configurations, optimizing their performance and reliability.
  • Environment Profiles: JKube supports environment-specific configurations. Developers can define profiles for different environments (such as development, staging, or production) and switch between them effortlessly. This feature ensures consistent deployments across various stages of the development pipeline.
  • Secrets Management: JKube facilitates the secure handling of sensitive information, such as API keys or passwords, through Kubernetes secrets. By integrating with Kubernetes secrets, developers can ensure that confidential data is protected and only accessible to authorized services.

3. Conclusion

In conclusion, anyone can harness the power of JKube to simplify Java application deployments on Kubernetes clusters directly from their familiar Eclipse environment. As the landscape of software development continues to evolve, mastering tools like JKube becomes pivotal. With this, developers are empowered to enhance their productivity, optimize their development processes, and ensure seamless deployments of Java applications in Kubernetes environments.

By bridging the gap between Java development and Kubernetes deployment within Eclipse, JKube encourages developers to explore further, experiment, and innovate. Happy Learning and do not forget to share!


An experience full-stack engineer well versed with Core Java, Spring/Springboot, MVC, Security, AOP, Frontend (Angular & React), and cloud technologies (such as AWS, GCP, Jenkins, Docker, K8).
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