cri-o VS community

Kubernetes on the backend used to utilize docker for much of its container runtime solutions. One of the modular features of Kubernetes is the ability to utilize a Container Runtime Interface or CRI. The problem was that Docker didn't really meet the spec properly and they had to maintain a shim to translate properly. Instead users could utilize the popular containerd or cri-o runtimes. These follow the Open Container Initiative or OCI's guidelines on container formats.

Multiple container runtimes are supported, like conatinerd, cri-o, or other CRI compliant runtimes.

Install container runtime on all nodes. We will use cri-o.

Container Runtime Interface (CRI) is one of the important parts of the Kubernetes cluster. It is a plugin interface allowing kubelet to use different container runtimes. And recently CRI-O container runtime has been announced as a CNCF Graduated project. I thought of writing a blog on CRI-O and how to set up a single-node Kubernetes cluster with Kubeadm and CRI-O.

CRI-O: This is an open-source container runtime designed for use with Kubernetes. It is a lightweight and stable environment for containers. It also complies with the Kubernetes Container Runtime Interface (CRI), making it easy to integrate with Kubernetes.

With CRI-O I believe you can configure registry mirror locations…. Similar to this: https://github.com/cri-o/cri-o/issues/4941

Alternatives like Podman and CRI-O continue to gain traction and may replace Docker in various places. For example, Kubernetes used to use Docker, then moved to containerd, and now also support CRI-O. Generally speaking, the core features of "Docker" are such a commodity now that no one was the wiser when Kubernetes stopped using it.

will the site be available for the CKA exam? https://github.com/cri-o/cri-o/blob/main/install.md

The CRI-O container engine provides a stable, more secure, and performant platform for running Open Container Initiative (OCI) compatible runtimes. CRI-Os purpose is to be the container engine that implements the Kubernetes Container Runtime Interface (CRI) for OpenShift Container Platform and Kubernetes, replacing the Docker service. Source

Multiple container runtimes are supported, like conatinerd, cri-o, or other CRI compliant runtimes.

More recently, the Kubernetes SIG Network has been evolving the Gateway API to support service meshes.

https://github.com/kubernetes/kubernetes https://www.kubernetes.dev/resources/calendar/ https://github.com/kubernetes/community/blob/master/governance.md https://github.com/kubernetes/steering https://github.com/kubernetes/community/blob/master/sig-list.md

According to this doc it takes the average of CPU utilization of a pod (average across the last 1 minute) divided by the CPU requested by the pod. Then it computes the arithmetic mean of all the pods' CPU.

metrics-server has not supported kubectl top Resource Metrics API

With the Gateway API being a superset of the Ingress API, it might make sense to consolidate both. Thanks to the SIG Network community, Gateway API is still growing and will soon be production ready.

Projects in/around Kubernetes and the CNCF are generally where I spend what little time I can these days. Most communities are incredibly welcoming and provide timely feedback. But the problem space of "managing a cloud platform" can take several years to really wrap ones head around, setting aside focused topics via SIGs like networking, storage, observability, API design, etc.

Krew is a plugin manager maintained by the Kubernetes Special Interest Group (SIG) CLI community. Krew makes it easy to use kubectl plugins and helps you discover, install, and manage them on your machine. It is similar to tools like apt, dnf, or brew. Today, over 200 kubectl plugins are available on Krew - and that number is only increasing. Some projects are actively used and some get deprecated over time, but are still accessible via Krew.

[1] https://k8s.devstats.cncf.io/d/9/companies-table?orgId=1&var-period_name=Last%20decade&var-metric=contributions [2] https://kubernetes.io/releases/release/ [3] https://github.com/kubernetes/community/blob/master/governance.md [4] https://github.com/kubernetes/community/blob/master/sig-list.md