krew VS kubebuilder

Authenticating with Kyma is a (in my opinion) unnecessary challenge as it leverages the OIDC-login plugin for kubectl. You find a description of the setup here. This works fine when on a Mac but can give you some headaches on a Windows and on Linux machine especially when combined with restrictive setups in corporate environments. For Windows I can only recommend installing krew via chocolatey and then install the OIDC plugin via kubectl krew install oidc-login. At least for me that was the only way to get this working on Windows.

( set -x; cd "$(mktemp -d)" && OS="$(uname | tr '[:upper:]' '[:lower:]')" && ARCH="$(uname -m | sed -e 's/x86_64/amd64/' -e 's/\(arm\)\(64\)\?.*/\1\2/' -e 's/aarch64$/arm64/')" && KREW="krew-${OS}_${ARCH}" && curl -fsSLO "https://github.com/kubernetes-sigs/krew/releases/download/v0.4.4/krew-linux_amd64.tar.gz" && tar zxvf "${KREW}.tar.gz" && ./"${KREW}" install krew )

Krew is a way to manage plugins for Kubernetes. For more info, check out the following link: https://krew.sigs.k8s.io/

I plan on getting it added as a krew plugin, so watch this space.

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.

kubectl plugins can be installed in numerous ways, the easiest way would be to install the official plugin manager called krew.

( set -x; cd "$(mktemp -d)" && OS="$(uname | tr '[:upper:]' '[:lower:]')" && ARCH="$(uname -m | sed -e 's/x86_64/amd64/' -e 's/\(arm\)\(64\)\?.*/\1\2/' -e 's/aarch64$/arm64/')" && KREW="krew-${OS}_${ARCH}" && curl -fsSLO "https://github.com/kubernetes-sigs/krew/releases/latest/download/${KREW}.tar.gz" && tar zxvf "${KREW}.tar.gz" && ./"${KREW}" install krew )

-- What is Krew?

The Spin operator uses the Kubebuilder framework and contains a Spin App Custom Resource Definition (CRD) and controller. It watches Spin App Custom Resources and realizes the desired state in the K8s cluster. Aside from the immediate benefits gained by running Wasm workloads in k8s, additional optimizations such as Horizontal Pod Scaling (HPA) and k8s Event-driven Autoscaling (KEDA) can be achieved in a pinch.

kubebuilder: brew install kubebuilder

The operator that I've been working on is designed to manage the full lifecycle of a QuestDB database instance, including version and hardware upgrades, config changes, backups, and (eventually) recovery from node failure. I used the Operator SDK and kubebuilder frameworks to provide scaffolding and API support.

Recently, I've been spending a lot of time writing a Kubernetes operator using the go operator-sdk, which is built on top of the Kubebuilder framework. This is a list of a few tips and tricks that I've compiled over the past few months working with these frameworks.

Since we built our operator using the Kubebuilder framework, most standard monitoring tasks were handled for us out-of-the-box. Our operator automatically exposes a rich set of Prometheus metrics that measure reconciliation performance, the number of k8s API calls, workqueue statistics, and memory-related metrics. We we were able to ingest these metrics into pre-built dashboards by leveraging the grafana/v1-alpha plugin, which scaffolds two Grafana dashboards to monitor Operator resource usage and performance. All we had to do was add these to our existing Grafana manifests and we were good to go!

I wrote a CSI driver and some operators. I admire K8s, because you can find solution to almost any problem in the source code - API versioning, load balancing, request throttling, optimistic concurrency, security, and much much more. I recommend https://book.kubebuilder.io/ It is similar to Operator SDK, but without Openshift-specific stuff. It gradually introduces you to many k8s concepts, and follows design patterns that k8s uses internally.

Do you mean this: https://book.kubebuilder.io/ ?

https://book.kubebuilder.io/ all you need to know

A better way to write an operator these days is to use kubebuilder [1].

My complaint is that I have seen orgs write operators for random stuff, often reinventing the wheel. Lot of operators in orgs are result of resume driven development. Having said that it often comes handy for complex orchestration.

[1]https://github.com/kubernetes-sigs/kubebuilder