IBM Client Developer Advocacy App Modernization Series

Lab - Migrating Legacy JEE apps to OpenShift in a multi-user lab environment

Working with Templates

Overview

OpenShift Templates provide a parameterized set of objects that can be processed by OpenShift. Templates enable developers to create repeatable parameterized deployments that minimize mistakes due to user error.

In this lab you'll use these capabilities can be used to deploy a small legacy Java EE app to OpenShift in a multi-user OpenShift environment

Step 1: Logon into the OpenShift Web Console and to the OpenShift CLI

1.1 login into the OpenShift web console using the user credentials provided to you

1.2 From the OpenShift web console click on your username in the upper right and select Copy Login Command

1.3 Paste the login command in a terminal window and run it (Note: leave the web console browser tab open as you'll need it later on in the lab)

Step 2: Pull the Websphere Liberty base image from Docker Hub and push it to the OpenShift internal registry

2.1 Get the hostname of your OpenShift internal registry so you can push images to it

export INTERNAL_REG_HOST=`oc get route docker-registry --template='{{ .spec.host }}' -n default`

2.2 Create a new OpenShift project for this lab (Note: your project name must be unique. We suggest you use pbw-usernnn where usernnn is your username for the project name e.g. user012)

oc new-project [YOUR PROJECT NAME]

2.3 Download the Websphere Liberty base image

docker pull websphere-liberty:javaee7

2.4 Tag the Websphere Liberty base image from Docker Hub appropriately for the internal registry

docker tag websphere-liberty:javaee7  $INTERNAL_REG_HOST/`oc project -q`/websphere-liberty:javaee7

2.5 Login to the internal registry

docker login -u `oc whoami` -p `oc whoami -t` $INTERNAL_REG_HOST

2.6 Push the Websphere Liberty base image to the internal registry

 docker push $INTERNAL_REG_HOST/`oc project -q`/websphere-liberty:javaee7

Step 3: Install MariaDB from the OpenShift template catalog

3.1 In your Web console browser tab under My Projects click on View All

3.2 Click on your project e.g. pbw-user012

3.3 Click on Browse Catalog

3.4 Select the Databases category, click MariaDB and then MariaDB (Ephemeral)

3.5 Click Next

3.6 Enter the following values for the fields indicated below (leave remaining values at their default values)

Field name	Value
MariaDB Connection Username	pbwadmin
MariaDB Connection Password	l1bertyR0cks
MariaDB Database Name	plantsdb

When you're done the dialog should look like the following:

3.7 Scroll down to the Labels section and change the app label value to pbw-liberty-mariadb

3.8 Click Next

3.9 Under Create a binding for MariaDB (Ephemeral) select Create a secret in pbw-usernnn to be used later

3.10 Click Create and then click Continue to the project overview

3.11 Verify that the Pod for the MariaDB deployment eventually shows as running

Step 4: Clone the Github repo that contains the code for the Plants by WebSphere app

4.1 Login in your Github account

4.2 In the search bar at the top left type in app-modernization-plants-by-websphere-jee6

4.3 Select the repository IBMAppModernization\app-modernization-plants-by-websphere-jee6 and then click on the Fork icon

4.4 Click the Clone or download button from your copy of the forked repo and copy the HTTPS URL to your clipboard

4.5 From your terminal go back to your home directory

cd ~

4.6 From the client terminal window clone the Git repo with the following commands appending the HTTPS URL from your clipboard

git clone [HTTPS URL for NEW REPO]
cd app-modernization-plants-by-websphere-jee6

Step 5: Install the Plants by WebSphere Liberty app using a template that utilizes S2I to build the app image

5.1 Add the Plants by WebSphere Liberty app template to your OpenShift cluster

oc create -f openshift/templates/docker/pbw-liberty-template.yaml

5.2 In your Web console browser tab make sure you're in the pbw-usernnn project (top left) and click on Add to Project -> Browse Catalog (top right)

5.3 Select the Other category and then click Plants by WebSphere on Liberty

5.4 Enter the URL of your clone of the Plants by WebSphere Github repository

5.5 Accept all the other default values and click Create

5.6 Click Continue to the project overview

5.7 Wait until the Pod for the Plants by WebSphere app on Liberty shows as running and then click on the route to get to the app's endpoint

Step 6: Test the Plants by WebSphere app

6.1 From the Plants by WebSphere app UI, click on the HELP link

6.2. Click on Reset database to populate the MariaDB database with data

6.3. Verify that browsing different sections of the online catalog shows product descriptions and images.

Summary

With even small simple apps requiring multiple OpenShift objects, templates greatly simplify the process of distributing OpenShift apps.