This article builds upon an old post I wrote many years ago: Kubernetes PVC stuck in Terminating state. That post covered the symptoms and quick fixes. This one is for platform engineers and Kubernetes operators who want to understand why resources like PVCs get stuck in Terminating, how Kubernetes handles deletion internally, and what it … Continue reading Kubernetes Finalizers: Deep Dive into PVC Deletion
When deploying workloads in Kubernetes, controlling where your pods land is crucial. Two primary mechanisms facilitate this: nodeSelector and nodeAffinity. While they might seem similar at first glance, they serve different purposes and offer varying degrees of flexibility. The Basics: nodeSelector The nodeSelector is the simplest way to constrain pods to specific nodes. It matches … Continue reading Kubernetes Scheduling: nodeSelector vs nodeAffinity
A quick tip and bit of code: if you’re outputting a lot of Kubernetes metadata using the –show-labels command, it can feel like looking for a needle in a haystack. The snippet below colorizes key label outputs to make them stand out. The Code Snippet When working with Kubernetes, it can be helpful to visually … Continue reading Highlight Kubernetes Labels in your Terminal with AWK
Recently, I’m seeing more and more queries about migrating to Cilium within an existing Red Hat OpenShift cluster, due to Cilium’s advanced networking capabilities, robust security features, and enhanced observability out-of-the-box. This increase of interest is also boosted by the fact that Cilium became the first Kubernetes CNI to graduate in the CNCF Landscape. In … Continue reading How to migrate from Red Hat OpenShiftSDN/OVN-Kubernetes to Cilium
The Issue Whilst trying to install the Metric’s server: kubectl apply -f https://github.com/kubernetes-sigs/metrics-server/releases/latest/download/components.yaml so I could use kubectl top node for it’s metrics on Node resource useage, I found the pods were not loading, and upon inspection found the following: > kubectl logs -n kube-system metrics-server-6f6cdbf67d-v6sbf I0717 12:19:32.132722 1 server.go:187] “Failed probe” probe=”metric-storage-ready” err=”no metrics … Continue reading Kubernetes Metric Server – cannot validate certificate because it doesn’t contain any IP SANs