Workshop Exercise - Deploy a Pet App

Table of Contents

Optional Exercise

This is an optional exercise. It is not required to successfully complete the workshop, but we recommended trying it if time allows. Review the objectives listed in the next section to decide if you want to do this exercise or if you would rather skip ahead to the next exercise:



Step 1 - The Traditional Application Lifecycle

Let’s take a step back and think about why we want to do an in-place upgrade. Wouldn’t it be best practice to deploy a new server or VM instance with the new RHEL version and then do a fresh install of our application from there?

Step 2 - Installing Our Beloved Pet Application

In this step, we are going to install an example application. We are going to install the old fashioned way: manually by following a traditional written procedure of confusing and potentially error prone command line steps. After all, if our app deployment was automated end-to-end, we wouldn’t need to upgrade in-place.

You may want to install a different application, for example, an actual application from your enterprise environment that you would like to test for potential impacts. Feel free to skip the procedure below and make your own adventure. Just take care to test your app both before and after the upgrade.

Step 3 - Test the Pet Application

Now that we have installed our application and verified it is running, it’s time to test how it works.

Step 4 - Configure the Application to Start on Reboot

Right now, our application was started manually. We need to configure the app so it will start up automatically when our server is rebooted.

Step 5 - Run Another Pre-upgrade Report

Whenever changes are made to a server, its a good idea to rerun the Leapp pre-upgrade report to make sure those changes have not introduced any new risk findings.


In this exercise, we discussed the sorry state of traditional application maintenance, untracked drift and technical debt. We installed a 3rd-party Java runtime and then installed the Pet Clinic application on top of that. We made certain that our app is functioning as expected, but we also discovered a new “high risk” finding on our pre-upgrade report.

Congratulations on completing all the exercises in the first section of the workshop. It’s time now to upgrade RHEL and see if there will be any application impact.


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