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.
During EndpointSlice reconcilation, EndpointSliceTracker is supposed to
track expected EndpointSlice resource versions so that external changes
to them can be detected. But it actually tracked the stale resource
version and resulted in every Service was handled twice as it always
received an EndpointSlice update with a different resource version but
was actually created/updated by itself during the first processing.
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 ended up causing far more problems than it was worth, especially
given that it just attempted to provide backwards compatibility with
the alpha release.
This adds a new Label to EndpointSlices that will ensure that multiple
controllers or entities can manage subsets of EndpointSlices. This
label provides a way to indicate the controller or entity responsible
for managing an EndpointSlice.
To provide a seamless upgrade from the alpha release of EndpointSlices
that did not support this label, a temporary annotation has been added
on Services to indicate that this label has been initially set on
EndpointSlices. That annotation will be set automatically by the
EndpointSlice controller with this commit once appropriate Labels have
been added on the corresponding EndpointSlices.
This was an oversight in the initial EndpointSlice release. This update
will ensure that Endpoints and EndpointSlices use the same logic to set
the Hostname attribute.
The Service spec includes a PublishNotReadyAddresses field which has
been used by Endpoints to report all matching resources ready. This may
or may not have been the initial purpose of the field, but given the
desire to provide backwards compatibility with the Endpoints API here,
it seems to make sense to continue to provide the same functionality.
syncService shouldn't return error if the service doesn't exist which
means it's triggered by service deletion, otherwise the service would be
enqueued repeatedly even its cleanup has been executed successfully.
This patch makes syncService return nil if the error is NotFound when
getting the service, like the other controllers do.
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.
