IBM WebSphere Application Server Liberty Core on OpenShift V3 Tutorial

A. Synopsis

What this is about

This project demonstrates how to use IBM WebSphere Liberty (a lightweight Java EE container comparable with Apache Tomcat) on Red Hat’s leading Platform-as-a-Service (PaaS) solution OpenShift Enterprise V3 (https://enterprise.openshift.com/. Since OpenShift is perfectly suited for running containerized workloads based on the Docker format, we could reuse the officially supported image built by IBM. Additionally we’ve added OpenShifts powerful templating mechanism in order to create a superior developer experience:

  • Self-service based provisioning of new IBM WebSphere Application Server Liberty Core containers
  • Existing, not yet containerized applications can simply be reused
  • No prior experience with Docker needed
  • Automated build & deploy life cycle

The source code can be found here: https://github.com/sebastianfaulhaber/openshift-v3-showcase/tree/master/websphere-liberty

Screenshots

1. Select WebSphere Liberty template

2. Provide details on application

3. Application artifacts successfully created

4. OpenShift automatically builds initial Docker image for application

5. Build and deployment completed successfully

6. IBM WebSphere Liberty startup screen

9. Demo application running

B. Installation

1. Setup OSE Environment

There are multiple ways to spin up a new OpenShift environment:

All-In-One VM

This community provided Vagrant box probably provides the most convenient and fastest way to start your OpenShift developer experience. It features a complete OpenShift installation within one VM that allows you to test all aspects of a container application platform.

See for detailed instructions: http://www.openshift.org/vm/

On premise installation

The instructions for setting up an on premise installation of OpenShift Enterprise V3 can be found here: ([https://docs.openshift.com/enterprise/3.1/install_config/install/index.html]https://docs.openshift.com/enterprise/3.1/install_config/install/index.html).

OpenShift Dedicated

OpenShift Dedicated is a new offering from OpenShift Online. OpenShift Dedicated offers a hosted OpenShift 3 environment to run the containers powering your applications. This offering provides an isolated instance hosted on Amazon Web Services (AWS), providing increased security and management by the OpenShift operations team, so that you have peace of mind about the stability and availability of the platform.

See https://www.openshift.com/dedicated/

2. Enable OpenShift to run Docker images with USER in the Dockerfile

The currently provided version of IBM’s WebSphere Liberty Docker image requires the use of USER in the Dockerfile. Due to the security implications raised by USER statements OpenShift restricts the use by default. In order to make this project work, you will need to relax the security settings as described here: https://docs.openshift.com/enterprise/3.1/admin_guide/manage_scc.html#enable-images-to-run-with-user-in-the-dockerfile.

# Login to your OpenShift master via SSH
su -
oc edit scc restricted
# Change the runAsUser.Type strategy to RunAsAny

3. Import template into your OpenShift environment

wget https://raw.githubusercontent.com/sebastianfaulhaber/openshift-v3-showcase/master/websphere-liberty/websphere-liberty-template.json
oc create -f websphere-liberty-template.json -n openshift

C. User guide

1. How can I access the provided demo application?

This project provides a simple Java EE web application that can be used to verify that the showcase is working. It can be accessed after provisioning via: /Sample1/SimpleServlet (e.g. http://liberty-app-http-route-demo.apps.example.com/Sample1/SimpleServlet).

2. How can I use this showcase in my own OpenShift installation?

  1. Create a fork of the repository in your own GIT environment
  2. Add your applications to the app/ folder. They will be picked up and get deployed automatically.
  3. Specify the URL to the forked project as SOURCE_REPOSITORY_URL when creating a new application.
  4. Done.

3. How can I automate the build & deployment lifecycle

The project template comes with preconfigured OpenShift webhook triggers for Github and a generic system (see https://docs.openshift.com/enterprise/3.1/dev_guide/builds.html#webhook-triggers for more details).

20. Configure webhook triggers

In order to automate the build and deployment lifecycle you simply need to integrate the webhook URLs according to your SCM specific instructions:

4. How can I view the logs of my application?

The logs can be accessed via the OpenShift Enterprise console:
Browse > Pods > YOUR_LIBERTY_POD > Logs. Alternatively you could also use the CLI command oc logs YOUR_LIBERTY_POD (https://docs.openshift.com/enterprise/3.1/cli_reference/basic_cli_operations.html#troubleshooting-and-debugging-cli-operations).

21. View application logs

5. How can I connect to the container instance that is running my application?

You can open a terminal connection to the container via the OpenShift Enterprise console: Browse > Pods > YOUR_LIBERTY_POD > Terminal. Alternatively you could also use the CLI command oc rsh YOUR_LIBERTY_POD (https://docs.openshift.com/enterprise/3.1/cli_reference/basic_cli_operations.html#troubleshooting-and-debugging-cli-operations.

22. Connecting to the container

D. Reference Information

WebSphere specific

OpenShift specific

E. Credits

Special thanks to Chris Eberle <ceberle@redhat.com>

Leave a Reply

Your email address will not be published. Required fields are marked *