MutatingWebhookConfiguration update issues

[xujinheng]

What would you like to be added:

1. Currently, the MutatingWebhookConfiguration is created by init-containers, which means if we want to update existing MutatingWebhookConfiguration, we have to do

kubectl delete -f install.yaml && kubectl create -f install.yaml

to let init-containers works again and check if existing MutatingWebhookConfiguration needs updating. If there a better way to do this? By Kubernetes operators?

2. The compare_mwc_fields function in imageswap-init.py only checks keys in new MutatingWebhookConfiguration now.

for key in sorted(new):

Which means if newer MutatingWebhookConfiguration has less key then the existing one, init-containers will assert them to be same, which is actually not.

Why is this needed:

To avoid MutatingWebhookConfiguration updating failures

[phenixblue]

You should be able to do something like this:

$ kubectl rollout restart deploy -n image swap-system imageswap

When the pods recycle, the init-container should run again.

The current state of image swap doesn't yield for a controller/operator pattern, but that may be an option once the project is ported to Golang.

I think I can add in a check to compare the len(new) and len(existing) to take care of the scenario you mentioned.

Let me know if that answers your questions/concerns.