Sometimes things go wrong. This section is meant to show you misconfigurations that can cause issues and how you would find/fix them.
The application used for this section is https://github.com/GoogleCloudPlatform/microservices-demo, but with a few intentional breaks.
You can find the specific modifications I made to the configuration here: sidpalas/microservices-demo#1. That being said, DON'T LOOK until you have already gone through the process of debugging it yourself.
The folks over at Learn K8s have published a very useful article and flow chart for troubleshooting deployments within kubernetes:
https://learnk8s.io/troubleshooting-deployments
This can provide a great structure for your debugging process.