April 11, 2017 ( last updated : April 10, 2017 )
openshift paas spring-boot

https://github.com/alainpham/rest-service

Abstract

Openshift is a PaaS solution based on Docker and Kubernetes. This article will show you how to install Openshift Origin in less than 5 minutes and deploy your first Java application to it.

Versions used

Centos 7
Openshift Origin Client v1.4.1

Install docker

sudo yum upgrade
sudo yum install docker

Edit /etc/sysconfig/docker and add these options

OPTIONS='--selinux-enabled --insecure-registry 172.30.0.0/16'

Execute docker without sudo

Replace the ${USER} by your user name

sudo groupadd docker
sudo gpasswd -a ${USER} docker

Reboot your machine

Test docker

sudo systemctl enable docker.service
sudo systemctl start docker.service
docker run hello-world

Expected result :

Hello from Docker!
This message shows that your installation appears to be working correctly.
....

Download Openshift client and install

https://www.openshift.org/download.html#oc-platforms

Place the oc executable in the $PATH

[demo@demo-centos-vm ~]$ oc version
oc v1.4.1+3f9807a
kubernetes v1.4.0+776c994

Launch Openshift Cluster

oc cluster up

-- Checking OpenShift client ... OK
...
   OpenShift server started.
   The server is accessible via web console at:
       https://YOUR_IP_ADDRESS:8443

   You are logged in as:
       User:     developer
       Password: developer

   To login as administrator:
       oc login -u system:admin

Open browser and to to https://YOUR_IP_ADDRESS:8443/ and login with user/pwd : developer/developer

Deploy sample application

In a shell log in as admin and add the Java S2I (source to image) image streams to the openshift project. This is important as we will use these images to build images from our own project source code

oc login -u system:admin
oc create -n openshift -f https://raw.githubusercontent.com/fabric8io-images/s2i/master/image-streams.json

Login as developer and add the application template of an app. You can customize these template as you wish. This is just an example of a Spring Boot java application that exposes a rest web service.

If you are interested in how to create a Spring Boot Application go to this article : quickstart-rest-microservice-with-spring-boot

In short the template describes

The BuildConfig : what base image needs to be used to build the images container here it's "fuse-java" (imported from the image stream previously)
The DeploymentConfig : which ports are exposed by each pod (container)
The Services: what services (tcp mostly) are exposed by the app. This is to have location independency to access services exposed by multiple pods (containers)
The Routes: in order to access a service from outside of Openshift, routes need to be created.

oc login -u developer
oc create https://raw.githubusercontent.com/alainpham/rest-service/master/openshift/openshift_origin.yml

Open browser and login as developer to your console https://YOUR_IP_ADDRESS:8443/

Go to My Project and Click on add to project

Add to project from template and select the previously added rest-service.

The template allows you ton change configurations before creating the different objects on the openshift cluster (i.e. BuildConfig, DeploymentConfig, Services, Routes ..)

The source is cloned from the git repository and built using the Source2Image method. Note that this is a Java project and all dependencies for the maven build needs to be downloaded. If you have an existing nexus or other maven repo you can configure it in the Maven Mirror Url. This could accelerate build time.

Click on create and wait for the build and deployments to occur.

Test by calling service.

curl http://YOUR_ROUTE_DOMAIN_NAME/svc/person/1

Expected result

{"id":1,"name":"John Doe"}

You can now also access infos about your running pods and access JMX methods and data through the Java Console

Thanks for reading

Other resources

Cloud Happiness - OpenShift Container Platform v3.4 install demo updated
Have your own Openshift Container Platform for development : Red Hat Container Development Kit

Originally published April 11, 2017
Latest update April 10, 2017

Related posts :

Openshift Quickstart in 5 minutes