Kompose - Maven Example

Fabric8 Maven Plugin + Kompose:

Let’s deploy a Springboot Java application with Docker Compose file using Fabric8 Maven Plugin to Kubernetes or OpenShift.

Requirements

1. Clone the example project from GitHub

$ git clone https://github.com/piyush1594/kompose-maven-example.git

Change current directory to kompose-maven-example directory.

$ cd kompose-maven-example

2. Add Fabric8 Maven Plugin to your project

$ mvn io.fabric8:fabric8-maven-plugin:3.5.28:setup

Add the Fabric8 Maven Plugin configuration to pom.xml of project. pom.xml is manifest or deployment descriptor file of a maven project.

3. Install Kompose through Maven

$ mvn fabric8:install

This command installs the kompose on the host.

4. Configure Fabric8 Maven Plugin to use a Docker Compose file

<plugin>
  <groupId>io.fabric8</groupId>
  <artifactId>fabric8-maven-plugin</artifactId>
  <configuration>
    <composeFile>path for docker compose file</composeFile>
  </configuration>
  <executions>
    <execution>
      <goals>
        <goal>resource</goal>
        <goal>build</goal>
      </goals>
    </execution>
  </executions>
</plugin>

Add the <configuration> and <executions> sections to pom.xml as shown in above pom.xml snippet. Update the <composeFile> to provide the relative path of Docker Compose file from pom.xml

5. Deploy application on Kubernetes or OpenShift

Make sure that Kubernetes/OpenShift cluster or Minikube/Minishift is running. In case, if anything of this is not running, you can run Minishift to test this application by using the following command.

$ minishift start

Below command deploys this application on Kubernetes or OpenShift.

$ mvn fabric8:deploy

Now that your service has been deployed, let’s access it by querying pod, service from Kubernetes or OpenShift.

$ oc get pods
NAME                                    READY     STATUS      RESTARTS   AGE
springboot-compose-1-xl0vb       1/1       Running     0          5m
springboot-compose-s2i-1-build   0/1       Completed   0          7m
$ oc get svc
NAME                        CLUSTER-IP       EXTERNAL-IP   PORT(S)    AGE
springboot-compose   172.30.205.137   <none>        8080/TCP   6m

Let’s access the Springboot service.

$ minishift openshift service --in-browser springboot-compose
Created the new window in existing browser session.

It will open your application endpoint in default browser.

Output-Diagram