Kompose-Example

A simple example to do practise of how to use docker-compose.yml file in fabric8-maven-plugin to generate Kubernetes/Openshift resource descriptors.

Fabric8 Maven Plugin + Kompose:

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

Requirements

• Linux or MacOS or Windows
• JDK 1.7+ - JDK Quick Installation Guide
• Maven 3.x+ - Maven Installation Guide
• Kompose - Kompose Installation Guide

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

Adds 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 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-docker-compose-1-xl0vb       1/1       Running     0          5m
springboot-docker-compose-s2i-1-build   0/1       Completed   0          7m

$ oc get svc
NAME                        CLUSTER-IP       EXTERNAL-IP   PORT(S)    AGE
springboot-docker-compose   172.30.205.137   <none>        8080/TCP   6m

Lets access the Springboot service.

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

It will open your application endpoint in default browser.