From the course: Debugging Kubernetes

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Debugging Pods running outdated Alpine Linux

Debugging Pods running outdated Alpine Linux - Kubernetes Tutorial

From the course: Debugging Kubernetes

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Debugging Pods running outdated Alpine Linux

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- [Instructor] We're now going to look at DNS problems that come about from running old versions of the Alpine Linux. While you will most likely not encounter this on newer Kubernetes clusters, this still pops up from time to time. Before we log in, let's learn more about how DNS works within Kubernetes. DNS within Kubernetes is not actually built into the cluster. It's an add-on that runs as a pod within the kube system namespace. There are two DNS add-ons that you'll likely work with, Core DNS and kube DNS. You'll usually see kube DNS installed on clusters that are very old. Usually running version 1.18 of Kubernetes or older. Most Kubernetes clusters these days will be using core DNS. Every pod in service within Kubernetes receives a DNS record issued by the clusters DNS add-on. However, you'll quickly notice that the records created for these resources are quite long, so let's break down how their hierarchy works. The last two parts of a record will always be the cluster's root…

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