Nice article, I like the emphasis that "you don't need anything else than HTTP and JSON to extend Kubernetes !". Regarding the use-case, I just want to note th

Nice article, I like the emphasis that "you don't need anything else than HTTP and JSON to extend Kubernetes !". Regarding the use-case, I just want to note that if you want to add a container next to every scheduled pod, it is best to have it be part of the pod itself rather than in another pod with another lifecycle. And to achieve that the best tool is not a plain controller, but a "mutating admission controller webhook", described here https://kubernetes.io/docs/reference/access-authn-authz/extensible-admission-controllers/#admission-webhooks https://kubernetes.io/docs/reference/access-authn-authz/exte..., which will allow you to, well, mutate, pod descriptions on the fly as they are submitted to the cluster (and add your sidecar container to it). Of course, the goal of the article is to demonstrate lifecycle management by reacting to change (a controller), so it's all fair in this case :).