endpointSliceTracker creates a set of resource versions for each
service, the resource versions in the set could be deleted when
endpointslices are deleted, but the set and its key in the map is never
deleted, leading to memory leak.
This patch deletes the set if the service is deleted, and stops
initializing an empty set when "read-only" methods "Has" and "Stale" are
called.
The EndpointSlice controller has the potential to manage a large number of resources that are updated frequently. Without proper backoffs in place, there is potential for it to unnecessarily overload the API Server with requests. This makes two significant changes: Increasing the base backoff from 5ms to 1s and making all syncs triggered by EndpointSlice changes delayed by at least 1 second to enable batching.
This adds a new EndpointSlice tracker to keep track of the expected resource versions of EndpointSlices associated with each Service managed by the EndpointSlice controller. This should prevent a potential race where a syncService call could happen with an incomplete view of EndpointSlices if additions or deletions hadn't fully propagated to the cache yet. Additionally, this ensures that external changes to EndpointSlices will be handled by the EndpointSlice controller.
This should fix a bug that could break masters when the EndpointSlice
feature gate was enabled. This was all tied to how the apiserver creates
and manages it's own services and endpoints (or in this case endpoint
slices). Consumers of endpoint slices also need to know about the
corresponding service. Previously we were trying to set an owner
reference here for this purpose, but that came with potential downsides
and increased complexity. This commit changes behavior of the apiserver
endpointslice integration to set the service name label instead of owner
references, and simplifies consumer logic to reference that (both are
set by the EndpointSlice controller).
Additionally, this should fix a bug with the EndpointSlice GenerateName
value that had previously been set with a "." as a suffix.
