webhook.md

Add a new webhook

Make sure you update the webhook configuration to add the object which needs to be mutated or validated.

Initiate it in main.go and use a optional configuration.

Example:

myAdmitter , err := myadmitter.NewAdmitter(&cfg.MyConfig)
	if err != nil {
		log.Fatalf("Unable to create Pod admitter: %v", err)
	}
    ...
	handler.Handle("/myendpoint", admission.Handler(myAdmitter))

The URL path has to match with service path in the webhook configuration.

To satisfy the Admitter interface you need to add an Admit method.

Example:

func (admitter *Admitter) Admit(request *v1admission.AdmissionRequest) ([]admission.PatchOperation, error) {
	if request.Resource != exampleResource {
		log.Errorf("invalid resource: %s (expected %s)", request.Resource, exampleResource)
		return nil, admission.InternalError
	}

	example := examplev1.Example{}
	if _, _, err := admission.Deserializer.Decode(request.Object.Raw, nil, &job); err != nil {
		log.Errorf("unable to parse example: %v", err)
		return nil, admission.InternalError
	}

	var result []admission.PatchOperation
	if job.Spec.TTLSecondsAfterFinished == nil {
		result = append(result, admission.PatchAdd("/spec/something", admitter.DefaultSomething)
	}
	return result, nil
}

It's important to know PatchOperation only support PatchAdd or PatchReplace, see patch.go.