HNC: cannot delete namespaces in 1.14

[adrianludwin]

Repro at head:

$ k hns create sub -n default
$ k delete subns sub -n default

Log messages show that the webhook is failing because we can't decode the old object. We should be skipping this.

If it turns out that this is actually working in 0.5, then we can change the milestone back to 0.6.

[adrianludwin]

This is due to the new object validator; the 0.5 validator didn't check deletions at all.

Why the object validator is being invoked on a namespace with no objects in it is somewhat of a mystery to me, but the logs certainly show this is happening (with an object name of ""!) in 1.14. Meanwhile, this works fine in 1.16. Perhaps it's some weird namespace-is-being-deleted code path.

Since the code is obviously wrong anyway, I'm going to go ahead and fix it. I'm not going to add any e2e tests though since 1.14 is very low priority.

[yiqigao217]

Do you mean that the cannot decode is in the object validator but not namespace validator? We added 1.14 backward compatibility (allow deleting in 1.14) in namespace validator. To fix this issue, is it that we need to also add it to object validator?

[adrianludwin]

Yeah. I don't understand it. Our namespace and anchor validators already handle a nil OldObject but the object validators didn't. This is a bug that needs to be fixed regardless, but I don't understand why the code was invoked when there were no objects at all.

[yiqigao217]

Not sure if you've already noticed. Even deleting a full namespace (not subnamespace) doesn't work in 1.14 using the head before your fix #890 .

[adrianludwin]

I hadn't. Wow. Makes sense though, I guess!