Getting Started on Okteto Cloud with Java

Okteto Cloud gives you free access to sandboxed Kubernetes namespaces, fully integrated with remote development capabilities. Develop your Kubernetes applications in Okteto Cloud and forget about slow and tedious local development forever.

This tutorial will show you how to create an account in Okteto Cloud and how to develop a Java sample application.

Prerequisites

Step 1: Deploy the Java Sample App

Get a local version of the Java Sample App by executing the following commands:

Gradle

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$ git clone https://github.com/okteto/java-gradle-getting-started
$ cd java-gradle-getting-started

Maven

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$ git clone https://github.com/okteto/java-maven-getting-started
$ cd java-maven-getting-started

The k8s.yml file contains the Kubernetes manifests of the Java Sample App. Deploy a dev version of the application by executing:

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$ kubectl apply -f k8s.yml
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deployment.apps "hello-world" created
service "hello-world" created

Open your browser and go to the URL of the application. You can get the URL by logging into Okteto Cloud and clicking on the application’s endpoint:

Did you notice that you are accessing your application through an HTTPs endpoint? This is because Okteto Cloud will automatically create them for you when you deploy your application. Cool no 😎?

Step 2: Start your remote development environment

You can also use Okteto Cloud to develop your applications directly in Kubernetes, avoiding dependencies on local installations and developing in a much more production-like environment. We are going to use the dev version of the Java Sample Application we just deployed as our remote development environment. To do that, run the following command:

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$ okteto up
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 ✓  Development environment activated
✓ Files synchronized
Namespace: cindy
Name: hello-world
Forward: 8080 -> 8080
8088 -> 8088

okteto>

The okteto up command starts a remote development environment, which means:

  • The Java Sample App container is updated with the Docker image maven:latest or gradle:latest, depending on the git repo you have cloned. This image contains the required dev tools to build, test and run a Java application.
  • A file synchronization service is created to keep your changes up-to-date between your local filesystem and your application pods.
  • A volume is attached to persist the Maven/Gradle cache in your development environment.
  • Container ports 8080 (the application) and 8088 (the debugger) are forwarded to localhost.
  • A remote shell is started in your remote development environment. Build, test and run your application as if you were in your local machine.

All of this (and more) can be customized via the okteto.yml manifest file. You can also use the file .stignore to skip files from file synchronization. This is useful to avoid synchronizing build artifacts or git metadata.

To run the application with Gradle, execute in the remote shell:

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okteto> gradle bootRun

If you are using Maven, execute:

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okteto> mvn spring-boot:run

The first time you run the application, Maven/Gradle will download your dependencies and compile your application. Wait for this process to finish. Go back to the browser, and reload the page to test that your application is running.

Step 3: Develop directly in Okteto Cloud

Open src/main/java/com/okteto/helloworld/RestHelloWorld.java in your favorite local IDE and modify the response message on line 11 to be Hello world from Okteto!. Save your changes.

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package com.okteto.helloworld;

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class RestHelloWorld {

@GetMapping("/")
public String sayHello() {
return "Hello world from Okteto!";
}
}

Your IDE will auto compile only the necessary *.class files which will be synchronized by Okteto to your application in Okteto Cloud. Take a look at the remote shell and notice how the changes are detected by Spring Boot and automatically hot reloaded.

To enable Spring Boot hot reloads the Java Sample App imports the spring-boot-devtools dependency.

Go back to the browser, and reload the page. Your code changes were instantly applied. No commit, build or push required 😎!

Step 4: Debug directly in Okteto Cloud

Okteto enables you to debug your applications directly from your favorite IDE. Let’s take a look at how that works in Eclipse, one of the most popular IDEs for Java development.

To enable debugging the Java Sample App defines the following JVM arguments in the Gradle/Maven configuration files: -agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=8088

Open the Debug configuration dialog, add a new Remote Java Application debug configuration, and point it to localhost:8088:

Click the Debug button to start a debugging session. Add a breakpoint on src/main/java/es/okteto/helloworld/RestHelloWorld.java, line 11. Go back to the browser, and reload the page. The execution will halt at your breakpoint. You can then inspect the request, the available variables, etc…

Next steps

Congratulations, you just developed your first Kubernetes application in Okteto Cloud 🚀.

Okteto lets you develop your application while taking advantage of other services running in Kubernetes. This way you can:

  • Reduce local setup and eliminate integration issues by developing the same way your application runs in production
  • Test your application as fast as you type code, without typing either docker or kubectl in your inner loop cycle
  • No more CPU cycles wasted in your machine. Hardware and network just limited by the power of the cloud

Okteto uses the okteto.yml file to determine the name of your development environment, the docker image to use and where to upload your code. Check the Okteto manifest docs to customize your development environments with your own dev tools, images, and dependencies to adapt Okteto to your own application.

Got questions? Join the conversation in our Kubernetes Slack channel! If you don’t have a Kubernetes slack account yet, sign up here. We’d love to hear from you.