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.
ServiceCIDRs are protected by finalizers and the CIDRs fields are
inmutable once set, only the readiness state impact the allocator
as it can only allocate IPs if any of the ServiceCIDR is ready.
The Add/Update events triggers a reconcilation of the current state
of the ServiceCIDR present in the informers with the existing IP
allocators.
The Delete events are handled directly to update or delete the
corresponing IP allocator.
The DRA plugin does that. It didn't actually work and only printed an error
message about NodeInfo not implementing klog.KMetata. That's not a compile-time
check due to limitations with Go generics and had been missed earlier.
The encoding/json package marshals []byte to a JSON string containing the base64 encoding of the
input slice's bytes, and unmarshals JSON strings to []byte by assuming the JSON string contains a
valid base64 text.
As a binary format, CBOR is capable of representing arbitrary byte sequences without converting them
to a text encoding, but it also needs to interoperate with the existing JSON serializer. It does
this using the "expected later encoding" tags defined in RFC 8949, which indicate a specific text
encoding to be used when interoperating with text-based protocols. The actual conversion to or from
a text encoding is deferred until necessary, so no conversion is performed during roundtrips of
[]byte to CBOR.
This finishes the transition to the assume cache as source of truth for the
current set of claims.
The tests have to be adapted. It's not enough anymore to directly put objects
into the informer store because that doesn't change the assume cache
content. Instead, normal Create/Update calls and waiting for the cache update
are needed.
This enables connecting the event handler for ResourceClaim to the assume
cache, which addresses a theoretic race condition.
It may also be useful for implementing the autoscaler support, because now
the autoscaler can modify the content of the cache.
