use Extraconfig to configure the repair interval
and add an integration test for services finalizers, and
possible races with the services repair loop.
Because the proxy.Provider interface included
proxyconfig.EndpointsHandler, all the backends needed to
implement its methods. But iptables, ipvs, and winkernel implemented
them as no-ops, and metaproxier had an implementation that wouldn't
actually work (because it couldn't handle Services with no active
Endpoints).
Since Endpoints processing in kube-proxy is deprecated (and can't be
re-enabled unless you're using a backend that doesn't support
EndpointSlice), remove proxyconfig.EndpointsHandler from the
definition of proxy.Provider and drop all the useless implementations.
Since the PR to do this deeper in the stack was declined, we'll do it
ourselves. This ensures that we don't accidentally mutate the input and
then compare that mutated form to the result (which caused previous test
failures).
This is the culmination of all the previous commits which made this last
move less dramatic. More tests and cleanup commits will follow.
Background, for future archaeologists:
Service has (had) an "outer" and "inner" REST handler. This is because of how we do IP and port allocations synchronously, but since we don't have API transactions, we need to roll those back in case of a failure. Both layers use the same `Strategy`, but the outer calls into the inner, which causes a lot of complexity in the code (including an open-coded partial reimplementation of a date-unknown snapshot of the generic REST code) and results in `Prepare` and `Validate` hooks being called twice.
The "normal" REST flow seems to be:
```
mutating webhooks
generic REST store Create {
cleanup = BeginCreate
BeforeCreate {
strategy.PrepareForCreate {
dropDisabledFields
}
strategy.Validate
strategy.Canonicalize
}
createValidation (validating webhooks)
storage Create
cleanup
AfterCreate
Decorator
}
```
Service (before this series of commits) does:
```
mutating webhooks
svc custom Create {
BeforeCreate {
strategy.PrepareForCreate {
dropDisabledFields
}
strategy.Validate
strategy.Canonicalize
}
Allocations
inner (generic) Create {
cleanup = BeginCreate
BeforeCreate {
strategy.PrepareForCreate {
dropDisabledFields
}
strategy.Validate
strategy.Canonicalize
}
createValidation (validating webhooks)
storage Create
cleanup
AfterCreate
Decorator
}
}
```
After this:
```
mutating webhooks
generic REST store Create {
cleanup = BeginCreate
Allocations
BeforeCreate {
strategy.PrepareForCreate {
dropDisabledFields
}
strategy.Validate
strategy.Canonicalize
}
createValidation (validating webhooks)
storage Create
cleanup
AfterCreate
Rollback allocations on error
Decorator
}
```
