Troubleshooting applications

In this section, we’ll focus on troubleshooting containerized applications deployed on the Kubernetes cluster. This commonly covers issues with containerized-application-related Kubernetes objects, including pods, containers, services, and StatefulSets. The troubleshooting skill that you will learn in this section will be helpful throughout your CKA exam.

Getting a high-level view

To troubleshoot the application failures, we have to start by getting a high-level view. The following command is the best way to get all the information at once:

kubectl get pods --all-namespaces

Alternatively, we can use the following:

kubectl get pods -A

The following output shows the pods up and running per namespace, within which you can easily find which pods have failed:

Figure 9.21 – Listing pods per namespace

To get the most out of the output information, note the NAMESPACE, READY, and STATUS columns –...