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https://github.com/rohankanojia/eclipse-jkube-demo-project

Deploy any Java application on Kubernetes using Eclipse JKube
https://github.com/rohankanojia/eclipse-jkube-demo-project

docker eclipse-jkube java kubernetes kubernetes-cluster maven openshift

Last synced: 15 days ago
JSON representation

Deploy any Java application on Kubernetes using Eclipse JKube

Host: GitHub
URL: https://github.com/rohankanojia/eclipse-jkube-demo-project
Owner: rohanKanojia
License: apache-2.0
Created: 2019-12-19T10:39:56.000Z (almost 5 years ago)
Default Branch: master
Last Pushed: 2024-08-13T14:18:51.000Z (3 months ago)
Last Synced: 2024-10-04T11:20:40.208Z (about 1 month ago)
Topics: docker, eclipse-jkube, java, kubernetes, kubernetes-cluster, maven, openshift
Language: Java
Homepage: https://github.com/eclipse/jkube
Size: 2.48 MB
Stars: 7
Watchers: 2
Forks: 8
Open Issues: 0
Metadata Files:
- Readme: readme.md
- License: license.txt

Awesome Lists containing this project

README

# Random Generator Application Demonstrating usage of Eclipse JKube for deploying onto Kubernetes

![Java CI with Maven](https://github.com/rohanKanojia/eclipse-jkube-demo-project/workflows/Java%20CI%20with%20Maven/badge.svg)
![License](https://img.shields.io/github/license/rohanKanojia/eclipse-jkube-demo-project)
[![Twitter](https://img.shields.io/twitter/follow/jkubeio?style=social)](https://twitter.com/jkubeio)

> Note: This a demo project for [Eclipse JKube](https://github.com/eclipse/jkube) for a blog. You can find full blog here: [Introduction to Eclipse JKube: Java tooling for Kubernetes/OpenShift](https://developers.redhat.com/blog/2020/01/28/introduction-to-eclipse-jkube-java-tooling-for-kubernetes-and-red-hat-openshift/)

> Note: This is a maven project demo-ing Eclipse JKube Kubernetes Maven Plugin. Gradle Users are advised to visit this repository: https://github.com/rohankanojia-forks/eclipse-jkube-demo-project-gradle

This is a simple random number generation application which just generates a random string on `/random` endpoint. It just
demonstrates usage of Eclipse JKube: https://github.com/eclipse/jkube

## Table of Contents:
* [How to Build](#How-to-build)
* [How to Run](#How-to-run)
* [Deploying on Kubernetes](#deploying-on-kubernetes)
* [Deploying on Red Hat OpenShift](#deploying-on-red-hat-openshift)
* [Migrating from Fabric8 Maven Plugin](#migrating-from-fabric8-maven-plugin)

## How to build
Just run `mvn clean install`

## How to run
Do `mvn spring-boot:run`

After spring boot initializes, just do a `curl localhost:8080/random` to check endpoint.

## Deploying on Kubernetes

### Building Docker image

In order to build docker image of your application, you just have to make sure your docker deamon is running. If using
minikube, you can simply do `eval $(minikube docker-env)` to expose docker deamon running inside minikube vm. Now in
order to build simply issue:

> mvn k8s:build

![Elipse JKube Build](screenshots/build.png)

### Pushing your created Docker Image to some container registry

Make sure you have your image name configured with respect to the registry you want to push to. In this case I would be pushing
it to Docker Hub. I have added this property which overrides name of the Image being used:
```

docker.io/rohankanojia/random-generator:${project.version}

```
I have my registry setting being defined in my `~/.m2/settings.xml` like this:
```

docker.io
rohankanojia
password

```
> mvn k8s:push

![Elipse JKube Build](screenshots/push.png)
Once pushed you can see your image being pushed to Docker registry like this:

![Elipse JKube Push_Result](screenshots/pushresult.png)

### Generating Kubernetes Manifests

Once your image is built, you need to generate Kubernetes resource manifests for your Deployments, Service etc. To do
it using Eclipse Jkube Kubernetes Maven Plugin just do:

> mvn k8s:resource

![Elipse JKube Resource](screenshots/resource.png)

### Deploying application onto Kubernetes

In order to deploy these generated manifests onto Kubernetes, just issue:

> mvn k8s:apply or mvn k8s:deploy

![Elipse JKube Resource](screenshots/apply1.png)

You'd observe they would be applied onto your Kubernetes Cluster. Right now Eclipse JKube has created a `Deployment` and a `Service` based on opinionated defaults. By default `Service` created is of type `ClusterIP`, which means it's only accessible from within the Kubernetes Cluster. That's why you see there is an ssh into minikube for accessing endpoint. If you want to access your application from outside the cluster you have to tell plugin to create service of type `NodePort` by specifying this property:
```

NodePort

```
After that you can notice that `mvn k8s:resource` goal would generate `Service` of type `NodePort`. Here is how it would look like in action:

![Elipse JKube Resource](screenshots/apply2.png)

### CleanUp: Un-deploy your application from Kubernetes cluster

If you want to un-deploy, we have this goal to delete all resources applied.

> mvn k8s:undeploy

![Elipse JKube Resource](screenshots/undeploy.png)

## Deploying on Red Hat OpenShift
[Red Hat OpenShift](https://www.openshift.com/) is Red Hat's official distribution of Kubernetes which empowers developers to innovate and ship faster with the leading hybrid cloud, enterprise container platform.

We would also be taking a look into how [Eclipse JKube OpenShift Maven Plugin](https://github.com/eclipse/jkube/tree/master/openshift-maven-plugin) can be used to deploy this random generator application on top of Red Hat OpenShift.

You can add it as a dependency in your project's `pom.xml` like this:
```

org.eclipse.jkube
openshift-maven-plugin
${jkube.version}

```

It's already added inside this project's `pom.xml`. So let's start by logging into our OpenShift cluster:
```
~/work/repos/eclipse-jkube-demo-project : $ oc login https://api.rh-idev.openshift.com --token=mytoken
Logged into "https://api.rh-idev.openshift.com:443" as "rohanKanojia" using the token provided.

You have one project on this server: "rokumar"

Using project "rokumar".
```

### Doing an S2I based build
OpenShift has a really nice [Source-to-image(S2I)](https://docs.openshift.com/container-platform/3.9/creating_images/s2i.html#creating-images-s2i) framework which eases writing images by just providing application source code as an input. Note that you would need to comment out `jkube.generator.name` property that we added during docker build in order to use this. OpenShift Maven Plugin relies on this for build process. Here is how it would look:
> mvn oc:build

>![Elipse JKube OMP build](screenshots/ocbuild.png)

Once build is complete you can see `BuildConfig` being created, OpenShift build process takes care of building and pushing the image to OpenShift's internal container registry:
```
[INFO] oc: Pushed 25/26 layers, 98% complete
[INFO] oc: Pushed 26/26 layers, 100% complete
[INFO] oc: Push successful
[INFO] oc: Build random-generator-s2i-2 in status Complete
[INFO] oc: Found tag on ImageStream random-generator tag: sha256:ebdc41d8cc09a91f2d05106885af137a64babceb35ed5add5d9a1c98e54bb244
[INFO] oc: ImageStream random-generator written to /home/rohaan/work/repos/eclipse-jkube-demo-project/target/random-generator-is.yml
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 02:51 min
[INFO] Finished at: 2020-06-07T15:35:26+05:30
[INFO] ------------------------------------------------------------------------
~/work/repos/eclipse-jkube-demo-project : $ oc get pods
NAME READY STATUS RESTARTS AGE
random-generator-2-jqsbf 1/1 Running 0 30s
~/work/repos/eclipse-jkube-demo-project : $ oc get bc
NAME TYPE FROM LATEST
random-generator-s2i Source Binary 2
~/work/repos/eclipse-jkube-demo-project : $ oc get build
NAME TYPE FROM STATUS STARTED DURATION
random-generator-s2i-2 Source Binary Complete 5 minutes ago 2m33s
~/work/repos/eclipse-jkube-demo-project : $
```

### Generating Red hat OpenShift manifests
Generating OpenShift manifests is not very different from generating Kubernetes manifests. Only `DeploymentConfig` is used in place of `Deployment`. Here is demonstration of `oc:resource` goal:

> mvn oc:resource

>![Elipse JKube OMP resource](screenshots/ocresource.png)

### Applying Generated manifests onto Red Hat OpenShift cluster

> mvn oc:apply or mvn oc:deploy

![Elipse JKube OMP apply](screenshots/ocapply.png)

Once deployed you can see your application inside OpenShift console:

![Elipse JKube OMP console](screenshots/occonsole.png)

You can then try to access your application via the created `Route`:
```
~/work/repos/eclipse-jkube-demo-project : $ oc get pods
NAME READY STATUS RESTARTS AGE
random-generator-3-8fqg4 1/1 Running 0 6m
random-generator-s2i-2-build 0/1 Completed 0 17m
~/work/repos/eclipse-jkube-demo-project : $ oc get routes
NAME HOST/PORT PATH SERVICES PORT TERMINATION WILDCARD
random-generator random-generator-rokumar.b6ff.rh-idev.openshiftapps.com random-generator 8080 None
~/work/repos/eclipse-jkube-demo-project : $ curl random-generator-rokumar.b6ff.rh-idev.openshiftapps.com/random | jq .
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 45 0 45 0 0 51 0 --:--:-- --:--:-- --:--:-- 51
{
"id": "5ab978c0-03c1-4532-9010-3422e58bc569"
}
~/work/repos/eclipse-jkube-demo-project : $
```

## Migrating from Fabric8 Maven Plugin

If you're using Fabric8 Maven Plugin to handle your Kubernetes/OpenShift operations, you can easily migrate to Eclipse JKube usingthe migrate goal:

```
mvn org.eclipse.jkube:kubernetes-maven-plugin:migrate
```

Please have a look at Eclipse JKube's [migration guide](https://www.eclipse.org/jkube/docs/migration-guide/) for more details.