Alas, Kubernetes has a steep learning curve and introduces yet another operational layer into the Java development process. Today we will show you how to use the Eclipse JKubeto simplify these additional operations related to Kubernetes and containers, and provide a painless migration to the cloud platform while maintaining the familiar Java ecosystem. Moreover, we will show how to deploy Java applications on the OpenShift platform using the OpenShift Maven plugin.
Traditional Java development process
The traditional Java development process (Figure 1) means that a developer writes code, then creates deployment units as JAR or WAR files, and then deploys and runs those files on a web or application server. Mostly they use Maven from the command line or use an IDE like IntelliJ or Eclipse to code and package applications. Developers are used to making changes to the code and testing everything thoroughly before committing the code and submitting it to source control.
Figure: 1. The traditional Java development process.
Java development process for the cloud
Moving to cloud applications adds Kubernetes and containers to the above schema . Therefore, the developer now needs to package Java applications into container images and create Kubernetes manifests describing these images. These manifests are then applied to the production server that Kubernetes is running on. In turn, Kubernetes takes these images from the registry and deploys applications according to the configurations that we have written in the manifests, which are usually YAML files.
The metamorphosis of traditional Java development in the transition to the cloud is shown in Fig. 2.
Figure: 2. Java development process for the cloud.
Eclipse JKube
Moving to Kubernetes adds another operational layer to the development process, and this is unnerving for many developers because they want to do their main job - the logic of the applications - not how to deploy them. This is where Eclipse JKube comes into play , which allows developers to use their libraries and plugins ( JKube Kit along with the Kubernetes Maven Plugin or OpenShift Maven Plugin ) to effortlessly perform container and Kubernetes-related operations following the diagram in Fig. 2.
In the remainder of this article, we will show you how to simplify the Java development process on Kubernetes using Eclipse JKube with the Kubernetes Maven Plugin.
Cloud development process using Eclipse JKube
Let's look at the slightly modified Java development framework for the cloud from Figure 2, introducing the Eclipse JKube and Kubernetes Maven Plugin, as shown in Figure 2. 3.
Figure: 3. Java development process for the cloud using Eclipse JKube.
As we can see, here all operations for interacting with Kubernetes and containers (highlighted in red in the diagram) are replaced by default Eclipse JKube goal tasks, which are listed in Table. 1.
Tab. 1. Eclipse JKube default tasks.
| Task | Stage | Description |
|---|---|---|
| k8s: build | PRE_INTEGRATION_TEST | Building docker images |
| k8s: push | INSTALL | Uploading docker images to the registry |
| k8s: resource | PROCESS_RESOURCES | Generating K8s manifests |
| k8s: apply | COMPILE | Applying Generated Manifests to K8s |
| k8s: undeploy | UNDEPLOY | Removing K8s assets that were deployed with k8s: apply and k8s: deploy |
Note: If you do not want tasks to use these opinionated defaults, you can manually customize Eclipse JKube for yourself, since it supports configuration via XML and resources .
Now let's look at examples of using the Eclipse JKube and Kubernetes Maven Plugin when working with applications.
Deploy Java application to Kubernetes using Eclipse JKube
In this example, we will deploy a simple Java application to the Minikube cluster using Eclipse JKube. Using the Kubernetes Maven Plugin, we can set deployment options without having to write any configuration.
As an example application, we use a simple random number generator that produces JSON-output at the / random endpoint:
~/work/repos/eclipse-jkube-demo-project : $ curl localhost:8080/random | jq .
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 45 0 45 0 0 818 0 --:--:-- --:--:-- --:--:-- 818
{
"id": "e80a4d10-c79b-4b9a-aaac-7c286cb37f3c"
}
Step 1. Download the Kubernetes Maven Plugin The
Kubernetes Maven Plugin is located in the Maven Central Repository . To use Eclipse JKube, you need to add the Kubernetes Maven Plugin to your pom.xml as a dependency:
<plugin>
<groupId>org.eclipse.jkube</groupId>
<artifactId>kubernetes-maven-plugin</artifactId>
<version>${jkube.version}</version>
</plugin>
If OpenShift is used instead of pure Kubernetes, then the pom.xml is modified as follows:
<plugin>
<groupId>org.eclipse.jkube</groupId>
<artifactId>openshift-maven-plugin</artifactId>
<version>${jkube.version}</version>
</plugin>
Step 2. Build the docker image The
application JAR file can be built with the mvn package command, and then you can use the mvn k8s: build goal task to build the docker image of this application. Note that we have overridden the default image name with this property:
<jkube.generator.name>docker.io/rohankanojia/random-generator:${project.version}</jkube.generator.name>
Before building the image, you need to make sure that the docker daemon is correctly exposed. This can be done with the following command:
$ eval $(minikube docker-env)
Then we enter the command mvn k8s: build, and this is what we see on the screen when building the docker image using the Eclipse JKube build task:
~/work/repos/eclipse-jkube-demo-project : $ mvn k8s:build
[INFO] Scanning for projects...
[INFO]
[INFO] ----------------------< meetup:random-generator >-----------------------
[INFO] Building random-generator 0.0.1
[INFO] --------------------------------[ jar ]---------------------------------
[INFO]
[INFO] --- kubernetes-maven-plugin:1.0.0-rc-1:build (default-cli) @ random-generator ---
[INFO] k8s: Running in Kubernetes mode
[INFO] k8s: Building Docker image in Kubernetes mode
[INFO] k8s: Running generator spring-boot
[INFO] k8s: spring-boot: Using Docker image quay.io/jkube/jkube-java-binary-s2i:0.0.7 as base / builder
[INFO] k8s: [docker.io/rohankanojia/random-generator:0.0.1] "spring-boot": Created docker-build.tar in 251 milliseconds
[INFO] k8s: [docker.io/rohankanojia/random-generator:0.0.1] "spring-boot": Built image sha256:a20e5
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 5.053 s
[INFO] Finished at: 2020-08-10T11:28:23+05:30
[INFO] ------------------------------------------------------------------------
~/work/repos/eclipse-jkube-demo-project : $
Step 3. Uploading the image to the docker registry
After we have built the docker image with the configured push registry (in our case, it is docker.io), we can push this image to the registry. This is what is displayed after we ask Eclipse JKube to execute the mvn k8s: push push task:
~/work/repos/eclipse-jkube-demo-project : $ mvn k8s:push
[INFO] Scanning for projects...
[INFO]
[INFO] ----------------------< meetup:random-generator >-----------------------
[INFO] Building random-generator 0.0.1
[INFO] --------------------------------[ jar ]---------------------------------
[INFO]
[INFO] --- kubernetes-maven-plugin:1.0.0-rc-1:push (default-cli) @ random-generator ---
[INFO] k8s: Running in Kubernetes mode
[INFO] k8s: Building Docker image in Kubernetes mode
[INFO] k8s: Running generator spring-boot
[INFO] k8s: spring-boot: Using Docker image quay.io/jkube/jkube-java-binary-s2i:0.0.7 as base / builder
[INFO] k8s: The push refers to repository [docker.io/rohankanojia/random-generator]
5dcd9556710f: Layer already exists
b7139ad07aa8: Layer already exists
b6f081e4b2b6: Layer already exists
d8e1f35641ac: Layer already exists
[INFO] k8s: 0.0.1: digest: sha256:9f9eda2a13b8cab1d2c9e474248500145fc09e2922fe3735692f9bda4c76002d size: 1162
[INFO] k8s: Pushed docker.io/rohankanojia/random-generator:0.0.1 in 7 seconds
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 11.222 s
[INFO] Finished at: 2020-08-10T11:35:37+05:30
[INFO] ------------------------------------------------------------------------
~/work/repos/eclipse-jkube-demo-project : $
After sending the image, you need to check that it is in the registry. In our case, we just see it in the Docker Hub, as shown in Fig. 4.
Figure: 4. The image uploaded to the registry appeared on the Docker Hub.
Step 4. Generating Kubernetes resource manifests for the application
So, we have assembled the application image, now we need to write Kubernetes manifests. To do this, Eclipse JKube has a task that generates hard resource manifests based on the underlying Java framework ( Spring Boot , Quarkus , Vert.x, or some other). You can also customize the manifest by using a config XML file and putting raw fragments (fragments of the required resource manifest) in the src / main / jkube application folder. In this case, your configuration will be uploaded to the generated manifests.
In our example, we leave everything as it is, and therefore the Eclipse JKube generates a manifest for the default deployment and for the service with the ClusterIP type. Then we modify the service manifest to change the service type to NodePort. You can override the default behavior using the following property:
<jkube.enricher.jkube-service.type>NodePort</jkube.enricher.jkube-service.type>
This is what the screen output looks like after we ask Eclipse JKube to execute the mvn k8s: resource resource task.
~/work/repos/eclipse-jkube-demo-project : $ mvn k8s:resource
[INFO] Scanning for projects...
[INFO]
[INFO] ----------------------< meetup:random-generator >-----------------------
[INFO] Building random-generator 0.0.1
[INFO] --------------------------------[ jar ]---------------------------------
[INFO]
[INFO] --- kubernetes-maven-plugin:1.0.0-rc-1:resource (default-cli) @ random-generator ---
[INFO] k8s: Running generator spring-boot
[INFO] k8s: spring-boot: Using Docker image quay.io/jkube/jkube-java-binary-s2i:0.0.7 as base / builder
[INFO] k8s: jkube-controller: Adding a default Deployment
[INFO] k8s: jkube-service: Adding a default service 'random-generator' with ports [8080]
[INFO] k8s: jkube-healthcheck-spring-boot: Adding readiness probe on port 8080, path='/actuator/health', scheme='HTTP', with initial delay 10 seconds
[INFO] k8s: jkube-healthcheck-spring-boot: Adding liveness probe on port 8080, path='/actuator/health', scheme='HTTP', with initial delay 180 seconds
[INFO] k8s: jkube-revision-history: Adding revision history limit to 2
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 3.344 s
[INFO] Finished at: 2020-08-10T11:38:11+05:30
[INFO] ------------------------------------------------------------------------
~/work/repos/eclipse-jkube-demo-project : $ ls target/classes/META-INF/jkube/kubernetes
random-generator-deployment.yml random-generator-service.yml
~/work/repos/eclipse-jkube-demo-project : $ cat target/classes/META-INF/jkube/kubernetes/random-generator-deployment.yml | head -n10
---
apiVersion: apps/v1
kind: Deployment
metadata:
annotations:
jkube.io/git-url: git@github.com:rohanKanojia/eclipse-jkube-demo-project.git
jkube.io/git-commit: 1ef9ef2ef7a6fcbf8eb64c293f26f9c42d026512
jkube.io/git-branch: master
jkube.io/scm-url: https://github.com/spring-projects/spring-boot/spring-boot-starter-parent/random-generator
jkube.io/scm-tag: HEAD
~/work/repos/eclipse-jkube-demo-project : $
Step 5. Deploy the application to the Kubernetes cluster
So, we are ready to deploy the application: we generated its image and then automatically generated resource manifests. Now all that remains is to apply all this to the Kubernetes cluster. To deploy the application, you can, of course, use the kubectl apply -f command, but the plugin can do this for us. This is what appears on the screen after we ask Eclipse JKube to execute the mvn k8s: apply apply task:
~/work/repos/eclipse-jkube-demo-project : $ mvn k8s:apply
[INFO] Scanning for projects...
[INFO]
[INFO] ----------------------< meetup:random-generator >-----------------------
[INFO] Building random-generator 0.0.1
[INFO] --------------------------------[ jar ]---------------------------------
[INFO]
[INFO] --- kubernetes-maven-plugin:1.0.0-rc-1:apply (default-cli) @ random-generator ---
[INFO] k8s: Using Kubernetes at https://192.168.39.145:8443/ in namespace default with manifest /home/rohaan/work/repos/eclipse-jkube-demo-project/target/classes/META-INF/jkube/kubernetes.yml
[INFO] k8s: Using namespace: default
[INFO] k8s: Creating a Service from kubernetes.yml namespace default name random-generator
[INFO] k8s: Created Service: target/jkube/applyJson/default/service-random-generator.json
[INFO] k8s: Creating a Deployment from kubernetes.yml namespace default name random-generator
[INFO] k8s: Created Deployment: target/jkube/applyJson/default/deployment-random-generator.json
[INFO] k8s: HINT: Use the command `kubectl get pods -w` to watch your pods start up
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 7.306 s
[INFO] Finished at: 2020-08-10T11:40:57+05:30
[INFO] ------------------------------------------------------------------------
~/work/repos/eclipse-jkube-demo-project : $ kubectl get pods -w
NAME READY STATUS RESTARTS AGE
random-generator-58b7847d7f-9m9df 0/1 Running 0 7s
random-generator-58b7847d7f-9m9df 1/1 Running 0 17s
^C~/work/repos/eclipse-jkube-demo-project : $ kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
io-openliberty-sample-getting-started NodePort 10.110.4.104 <none> 9080:30570/TCP 44h
kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 18d
random-generator NodePort 10.97.172.147 <none> 8080:32186/TCP 22s
~/work/repos/eclipse-jkube-demo-project : $ curl `minikube ip`:32186/random | jq .
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 45 0 45 0 0 1800 0 --:--:-- --:--:-- --:--:-- 1875
{
"id": "42e5571f-a20f-44b3-8184-370356581d10"
}
Step 6. We undeploy the application from the Kubernetes cluster
For this, the undeploy task is used, which simply deletes all the resources that were applied in the previous step, that is, when the apply task was executed. This is what we see on the screen after we ask Eclipse JKube to execute the mvn k8s: undeploy undeploy task:
~/work/repos/eclipse-jkube-demo-project : $ kubectl get all
NAME READY STATUS RESTARTS AGE
pod/random-generator-58b7847d7f-9m9df 1/1 Running 0 5m21s
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 18d
service/random-generator NodePort 10.97.172.147 <none> 8080:32186/TCP 5m21s
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/random-generator 1/1 1 1 5m21s
NAME DESIRED CURRENT READY AGE
replicaset.apps/random-generator-58b7847d7f 1 1 1 5m21s
~/work/repos/eclipse-jkube-demo-project : $ mvn k8s:undeploy
[INFO] Scanning for projects...
[INFO]
[INFO] ----------------------< meetup:random-generator >-----------------------
[INFO] Building random-generator 0.0.1
[INFO] --------------------------------[ jar ]---------------------------------
[INFO]
[INFO] --- kubernetes-maven-plugin:1.0.0-rc-1:undeploy (default-cli) @ random-generator ---
[INFO] k8s: Using Kubernetes at https://192.168.39.145:8443/ in namespace default with manifest /home/rohaan/work/repos/eclipse-jkube-demo-project/target/classes/META-INF/jkube/kubernetes.yml
[INFO] k8s: Using namespace: default
[INFO] k8s: Deleting resource Deployment default/random-generator
[INFO] k8s: Deleting resource Service default/random-generator
[INFO] k8s: HINT: Use the command `kubectl get pods -w` to watch your pods start up
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 3.412 s
[INFO] Finished at: 2020-08-10T11:46:22+05:30
[INFO] ------------------------------------------------------------------------
~/work/repos/eclipse-jkube-demo-project : $ kubectl get pods -w
^C~/work/repos/eclipse-jkube-demo-project : $ kubectl get all
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 18d
~/work/repos/eclipse-jkube-demo-project : $
What else can you do with Eclipse JKube
So, we've covered the main goals of the Eclipse JKube and Kubernetes Maven Plugin, which make it easy to develop Java applications for the Kubernetes platform. If you do not want to constantly enter these tasks from the keyboard, you can write them in the plugin configuration, for example, like this:
<plugin>
<groupId>org.eclipse.jkube</groupId>
<artifactId>kubernetes-maven-plugin</artifactId>
<version>${project.version}</version>
<executions>
<execution>
<goals>
<goal>build</goal>
<goal>resource</goal>
<goal>apply</goal>
</goals>
</execution>
</executions>
</plugin>
I must say that in this article we have considered far from all the goal-tasks that are in Eclipse JKube and Kubernetes Maven Plugin, therefore, we present in Table 2 a list of additional tasks that may also be useful to you.
Tab. 2. Additional Eclipse JKube Goals.
| Task | Stage | Description |
|---|---|---|
| k8s: log | VALIDATE | Receiving logs from an application running on Kubernetes. |
| k8s: debug | PACKAGE | Opening a debug port to debug your Kubernetes application directly from the IDE. |
| k8s: deploy | INSTALL | Forking the Install task and applying the generated manifests to the Kubernetes cluster is exactly the same as in the case of the apply task. |
| k8s: watch | PACKAGE | Automatic hot deployment of an application by tracking its namespace. |
Deploying Java Applications to Red Hat OpenShift Using the OpenShift Maven Plugin
To deploy the application from our example to the Red Hat OpenShift platform, we will use the OpenShift Maven plugin . The only difference is that the task prefix will change from k8s to oc. By default the plugin Kubernetes Maven makes docker -sborki and plug OpenShift Maven - assembly S2i . We do not make any changes to our project, except for removing the jkube.generator.name property, since it is not required when submitting to the registry (during the build phase, OpenShift places the image in its internal registry). And this is what will appear on the screen when we run our example, in which, by the way, we perform goal-tasks not one by one, but all at once:
~/work/repos/eclipse-jkube-demo-project : $ mvn oc:build oc:resource oc:apply
[INFO] Scanning for projects...
[INFO]
[INFO] ----------------------< meetup:random-generator >-----------------------
[INFO] Building random-generator 0.0.1
[INFO] --------------------------------[ jar ]---------------------------------
[INFO]
[INFO] --- openshift-maven-plugin:1.0.0-rc-1:build (default-cli) @ random-generator ---
[INFO] oc: Using OpenShift build with strategy S2I
[INFO] oc: Running in OpenShift mode
[INFO] oc: Running generator spring-boot
[INFO] oc: spring-boot: Using Docker image quay.io/jkube/jkube-java-binary-s2i:0.0.7 as base / builder
[INFO] oc: [random-generator:0.0.1] "spring-boot": Created docker source tar /home/rohaan/work/repos/eclipse-jkube-demo-project/target/docker/random-generator/0.0.1/tmp/docker-build.tar
[INFO] oc: Adding to Secret pullsecret-jkube
[INFO] oc: Using Secret pullsecret-jkube
[INFO] oc: Creating BuildServiceConfig random-generator-s2i for Source build
[INFO] oc: Creating ImageStream random-generator
[INFO] oc: Starting Build random-generator-s2i
[INFO] oc: Waiting for build random-generator-s2i-1 to complete...
[INFO] oc: Caching blobs under "/var/cache/blobs".
[INFO] oc: Getting image source signatures
[INFO] oc: Copying blob sha256:cf0f3ebe9f536c782ab3835049cfbd9a663761ded9370791ef6ea3965c823aad
[INFO] oc: Copying blob sha256:57de4da701b511cba33bbdc424757f7f3b408bea741ca714ace265da9b59191a
[INFO] oc: Copying blob sha256:f320f94d91a064281f5127d5f49954b481062c7d56cce3b09910e471cf849050
[INFO] oc: Copying config sha256:52d6788fcfdd39595264d34a3959464a5dabc1d4ef0ae188802b20fc2d6a857b
[INFO] oc: Writing manifest to image destination
[INFO] oc: Storing signatures
[INFO] oc: Generating dockerfile with builder image quay.io/jkube/jkube-java-binary-s2i:0.0.7
[INFO] oc: STEP 1: FROM quay.io/jkube/jkube-java-binary-s2i:0.0.7
[INFO] oc: STEP 2: LABEL "io.openshift.build.source-location"="/tmp/build/inputs" "io.openshift.build.image"="quay.io/jkube/jkube-java-binary-s2i:0.0.7"
[INFO] oc: STEP 3: ENV JAVA_APP_DIR="/deployments" OPENSHIFT_BUILD_NAME="random-generator-s2i-1" OPENSHIFT_BUILD_NAMESPACE="default"
[INFO] oc: STEP 4: USER root
[INFO] oc: STEP 5: COPY upload/src /tmp/src
[INFO] oc: STEP 6: RUN chown -R 1000:0 /tmp/src
[INFO] oc: STEP 7: USER 1000
[INFO] oc: STEP 8: RUN /usr/local/s2i/assemble
[INFO] oc: INFO S2I source build with plain binaries detected
[INFO] oc: INFO S2I binary build from fabric8-maven-plugin detected
[INFO] oc: INFO Copying binaries from /tmp/src/deployments to /deployments ...
[INFO] oc: random-generator-0.0.1.jar
[INFO] oc: INFO Copying deployments from deployments to /deployments...
[INFO] oc: '/tmp/src/deployments/random-generator-0.0.1.jar' -> '/deployments/random-generator-0.0.1.jar'
[INFO] oc: STEP 9: CMD /usr/local/s2i/run
[INFO] oc: STEP 10: COMMIT temp.builder.openshift.io/default/random-generator-s2i-1:48795e41
[INFO] oc: time="2020-08-10T06:37:49Z" level=info msg="Image operating system mismatch: image uses \"\", expecting \"linux\""
[INFO] oc: time="2020-08-10T06:37:49Z" level=info msg="Image architecture mismatch: image uses \"\", expecting \"amd64\""
[INFO] oc: Getting image source signatures
[INFO] oc: Copying blob sha256:d8e1f35641acb80b562f70cf49911341dfbe8c86f4d522b18efbf3732aa74223
[INFO] oc: Copying blob sha256:b6f081e4b2b6de8be4b1dec132043d14c121e968384dd624fb69c2c07b482edb
[INFO] oc: Copying blob sha256:b7139ad07aa8ce4ed5a132f7c5cc9f1de0f5099b5e155027a23d57f7fbe78b16
[INFO] oc: Copying blob sha256:98972fc90a1108315cc5b05b2c691a0849a149727a7b81e76bc847ac2c6d9714
[INFO] oc: Copying config sha256:27aaadaf28e24856a66db962b88118b8222b61d79163dceeeed869f7289bc230
[INFO] oc: Writing manifest to image destination
[INFO] oc: Storing signatures
[INFO] oc: --> 27aaadaf28e
[INFO] oc: 27aaadaf28e24856a66db962b88118b8222b61d79163dceeeed869f7289bc230
[INFO] oc: Getting image source signatures
[INFO] oc:
[INFO] oc: Pushing image image-registry.openshift-image-registry.svc:5000/default/random-generator:0.0.1 ...
[INFO] oc: Copying blob sha256:f320f94d91a064281f5127d5f49954b481062c7d56cce3b09910e471cf849050
[INFO] oc: Copying blob sha256:cf0f3ebe9f536c782ab3835049cfbd9a663761ded9370791ef6ea3965c823aad
[INFO] oc: Copying blob sha256:57de4da701b511cba33bbdc424757f7f3b408bea741ca714ace265da9b59191a
[INFO] oc: Copying blob sha256:98972fc90a1108315cc5b05b2c691a0849a149727a7b81e76bc847ac2c6d9714
[INFO] oc: Copying config sha256:27aaadaf28e24856a66db962b88118b8222b61d79163dceeeed869f7289bc230
[INFO] oc: Writing manifest to image destination
[INFO] oc: Storing signatures
[INFO] oc: Successfully pushed image-registry.openshift-image-registry.svc:5000/default/random-generator@sha256:aa9e1a380c04ef9174ba56459c13d44420ebe653ebf32884d60fe4306b17306d
[INFO] oc: Push successful
[INFO] oc: Build random-generator-s2i-1 in status Complete
[INFO] oc: Found tag on ImageStream random-generator tag: sha256:aa9e1a380c04ef9174ba56459c13d44420ebe653ebf32884d60fe4306b17306d
[INFO] oc: ImageStream random-generator written to /home/rohaan/work/repos/eclipse-jkube-demo-project/target/random-generator-is.yml
[INFO]
[INFO] --- openshift-maven-plugin:1.0.0-rc-1:resource (default-cli) @ random-generator ---
[INFO] oc: Using docker image name of namespace: default
[INFO] oc: Running generator spring-boot
[INFO] oc: spring-boot: Using Docker image quay.io/jkube/jkube-java-binary-s2i:0.0.7 as base / builder
[INFO] oc: jkube-controller: Adding a default DeploymentConfig
[INFO] oc: jkube-service: Adding a default service 'random-generator' with ports [8080]
[INFO] oc: jkube-healthcheck-spring-boot: Adding readiness probe on port 8080, path='/actuator/health', scheme='HTTP', with initial delay 10 seconds
[INFO] oc: jkube-healthcheck-spring-boot: Adding liveness probe on port 8080, path='/actuator/health', scheme='HTTP', with initial delay 180 seconds
[INFO] oc: jkube-revision-history: Adding revision history limit to 2
[INFO]
[INFO] --- openshift-maven-plugin:1.0.0-rc-1:apply (default-cli) @ random-generator ---
[INFO] oc: Using OpenShift at https://api.crc.testing:6443/ in namespace default with manifest /home/rohaan/work/repos/eclipse-jkube-demo-project/target/classes/META-INF/jkube/openshift.yml
[INFO] oc: OpenShift platform detected
[INFO] oc: Using project: default
[INFO] oc: Creating a Service from openshift.yml namespace default name random-generator
[INFO] oc: Created Service: target/jkube/applyJson/default/service-random-generator.json
[INFO] oc: Creating a DeploymentConfig from openshift.yml namespace default name random-generator
[INFO] oc: Created DeploymentConfig: target/jkube/applyJson/default/deploymentconfig-random-generator.json
[INFO] oc: Creating Route default:random-generator host: null
[INFO] oc: HINT: Use the command `oc get pods -w` to watch your pods start up
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 01:07 min
[INFO] Finished at: 2020-08-10T12:08:00+05:30
[INFO] ------------------------------------------------------------------------
~/work/repos/eclipse-jkube-demo-project : $ oc get pods -w
NAME READY STATUS RESTARTS AGE
random-generator-1-deploy 1/1 Running 0 14s
random-generator-1-vnrm9 0/1 Running 0 11s
random-generator-s2i-1-build 0/1 Completed 0 1m
random-generator-1-vnrm9 1/1 Running 0 24s
random-generator-1-deploy 0/1 Completed 0 28s
~/work/repos/eclipse-jkube-demo-project : $ oc get routes
NAME HOST/PORT PATH SERVICES PORT TERMINATION WILDCARD
random-generator random-generator-default.apps-crc.testing random-generator 8080 None
~/work/repos/eclipse-jkube-demo-project : $ curl random-generator-default.apps-crc.testing/random
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 45 0 45 0 0 1666 0 --:--:-- --:--:-- --:--:-- 1730
{
"id": "d80052d9-2f92-43cb-b9eb-d7cffb879798"
}
~/work/repos/eclipse-jkube-demo-project : $
Video tutorial
To learn more about how to simplify Kubernetes development with Eclipse JKube, watch the video tutorial on how to quickly deploy a simple Spring Boot application on Minikube:
Conclusion
In this article, we've shown how the Eclipse JKube makes life easier for a Java developer when working with Kubernetes. More information on the Eclipse JKube can be found on the project site and on GitHub .