Integration testing has to this point relied on patching serving codecs for built-in APIs. The
test-only patching is removed and replaced by feature gated checks at runtime.
When MultiCIDRServiceAllocator feature is enabled, we added an
additional feature gate DisableAllocatorDualWrite that allows to enable
a mirror behavior on the old allocator to deal with problems during
cluster upgrades.
During the implementation the secondary range of the legacy allocator
was initialized with the valuye of the primary range, hence, when a
Service tried to allocate a new IP on the secondary range, it succeded
in the new ip allocator but failed when it tried to allocate the same IP
on the legacy allocator, since it has a different range.
Expand the integration test that run over all the combinations of
Service ClusterIP possibilities to run with all the possible
combinations of the feature gates.
The integration test need to change the way of starting the apiserver
otherwise it will timeout.
MultiCIDRServiceAllocator implements a new ClusterIP allocator based on
IPAddress object to solve the problems and limitations caused by
existing bitmap allocators.
However, during the rollout of new versions, deployments need to support
a skew of one version between kube-apiservers. To avoid the possible
problem where there are multiple Services requests on the skewed
apiservers and that both allocate the same IP to different Services,
the new allocator will implement a dual-write strategy under the
feature gate DisableAllocatorDualWrite.
After the MultiCIDRServiceAllocator is GA, the DisableAllocatorDualWrite
can be enabled safely as all apiservers will run with the new
allocators. The graduation of DisableAllocatorDualWrite can also
be used to clean up the opaque API object that contains the old bitmaps.
If MultiCIDRServiceAllocator is enabled and DisableAllocatorDualWrite is disable
and is a new environment, there is no bitmap object created, hence, the
apiserver will initialize it to be able to write on it.
The repair loop controller watches the ServiceCIDRs configured
and use them to handle the repair of the IPAddresses assigned
by the kube-apiserver.
Change-Id: I8cfe8fd6285ea91192fc4ec72eaeea1eb004a235
Change-Id: If4be12e2c67b340d86c4efa2f9fb3672f0661636
Add feature gate ServiceIPStaticSubrange to enable a new strategy
in the Service IP allocators, so the IP range is is subdivided and
dynamic allocated addresses are allocated preferently from the
upper range.
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
}
```
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.
Rename `NewCIDRRange()` to `NewInMemory()`
Rename `NewAllocatorCIDRRange()` to `New()`
Rename `NewPortAllocator()` to `NewInMemory()`
Rename `NewPortAllocatorCustom()` to `New()`
Now the following flags have no effect and would be removed in v1.24:
* `--port`
* `--address`
The insecure port flags `--port` may only be set to 0 now.
Signed-off-by: Jian Zeng <zengjian.zj@bytedance.com>
