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jamiehannaford / what-happens-when-k8s

🤔 What happens when I type kubectl run?
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Is Initializers part of the admission controller chain #32

Open jianlongzhou opened 4 years ago

jianlongzhou commented 4 years ago

From this doc document: https://v1-16.docs.kubernetes.io/docs/reference/access-authn-authz/admission-controllers/.

An admission controller is a piece of code that intercepts requests to the Kubernetes API server prior to persistence of the object, but after the request is authenticated and authorized.

But this article says that

After an object is persisted to the datastore, it is not made fully visible by the apiserver or scheduled until a series of intializers have run.

navaati commented 4 years ago

Hi.

It seems Initializers were an Alpha concept and were abandoned in this form (see https://github.com/kubernetes/kubernetes/pull/72972).

However, don't mourn them, because their functionality is provided by a special Admission Controller called "MutatingAdmissionWebhook" (see beginning of this paragraph) !

That way, instead of a new, different concept, it's unified with Admission Controllers and that's one less thing to know :).