This includes a few cases.
1) TestCreateIgnoresIPFamilyForExternalName: Prove that ExternalName is
ignored for dual-stack. A small set of test cases were chosen to
demonstrate.
2) TestCreateIgnoresIPFamilyWithoutDualStack: Prove that when the
dual-stack gate is off, all services are ignored for dual-stack. A
small set of test cases were chosen to demonstrate
3) TestCreateInitIPFields: Run over a huge array of test cases for
dual-stack. This was generated by this program:
https://gist.github.com/thockin/cccc9c9a580b4830ee0946ddd43eeafe and
then updated by hand.
Gut the "outer" Create() and move it to the inner BeginCreate(). This
uses a "transaction" type to make cleanup functions easy to read.
Background:
Service has 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 commit) 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 commit:
```
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
}
```
This same fix pattern will be applied to Delete and Update in subsequent
commits.
All the logic remains unchanged, just reorganized. The functions are
imperfect but emphasize the change being made and can be cleaned up
subsequently.
This makes the following steps easier to comprehend.
Move all allocator-related methods onto the alloc object so it can be
used in either REST layer. There's an INORDINATE amount of test code
here and I am skeptical that it is all useful. That's for later
commits.
A pod that has been rejected by admission will have status manager
set the phase to Failed locally, which make take some time to
propagate to the apiserver. The rejected pod will be included in
admission until the apiserver propagates the change back, which
was an unintended regression when checking pod worker state as
authoritative.
A pod that is terminal in the API may still be consuming resources
on the system, so it should still be included in admission.
The iptables rule that matches kubeNodePortLocalSetSCTP must be inserted
before the one matches kubeNodePortSetSCTP, otherwise all SCTP traffic
would be masqueraded regardless of whether its ExternalTrafficPolicy is
Local or not.
To cover the case in tests, the patch adds rule order validation to
checkIptables.
