3.3 Additional Labs on Application Migration and Modernization Techlab

3.3.1 Debugging

Mon, 01 Jan 0001 00:00:00 +0000

Task 3.3.1.1: Prepare Test Application

First create a project called “debugbox-<username>”.

oc new-project debugbox-<username>

Replace <username> with your username!

Deploy test application

A minimal container image is suitable for testing, e.g. a Go application in an empty file system (From scratch): s3manager

Create a new application from this image:

Image: quay.io/puzzle/s3manager:latest
Environment:
- ACCESS_KEY_ID=something
- SECRET_ACCESS_KEY=x

oc new-app -e ACCESS_KEY_ID=something -e SECRET_ACCESS_KEY=x quay.io/puzzle/s3manager:latest --allow-missing-images

Since OpenShift 4.5 oc new-app creates a Deployment not a DeploymentConfig.

Task 3.3.1.2: Debugging with the oc tool

Try to open a remote shell in the container:

3.3.2 Autoscaling

Mon, 01 Jan 0001 00:00:00 +0000

In this example we will scale an automated application up and down, depending on how much load the application is under. For this we use an Ruby example webapp.

We first check that the project is ready for the lab.

Ensure that the LAB_USER environment variable is set.

echo $LAB_USER

If the result is empty, set the LAB_USER environment variable.

command hint

export LAB_USER=<username>

Create a new project to for the autoscale lab.

3.3.3 Kafka local

Mon, 01 Jan 0001 00:00:00 +0000

Your WEB-IDE does not contain the needed tools for this lab. When you like to do it, you have to install the tools (Docker, docker-compose) on your computer.

Task 3.3.3.1: Run an event driven application on your computer

Let’s get our kafka instance, producer and consumers up and running on your local machine.

This is the correspondent lab to Event driven architecture with Apache Kafka where you run the application on OpenShift.

With the following docker-compose file you can start your own local kafka cluster.