ReplaceFeatureGates logs a warning when the default env var
implementation has been already used.
Such a situation indicates a potential ordering issue and usually is unwanted.
This PR add a feature gates mechanisim to client-go
as described in https://docs.google.com/document/d/1g9BGCRw-7ucUxO6OtCWbb3lfzUGA_uU9178wLdXAIfs
In particular:
- Adds a default feature gate implementation based on environment variables.
- Adds a set of methods for reading, overwriting the default implementation, and adding features to an external registry.
Co-authored-by: deads2k <deads@redhat.com>
Co-authored-by: Ben Luddy <bluddy@redhat.com>
Removes kube-proxy specific proxy type detection and globally increases
the timeout for session affinity testing so that it works for more
use-cases by default (noteably including IPVS)
In particular, fix the description of ServiceChangeTracker.Update's
return value, and point out that it's different from
EndpointsChangeTracker.EndpointSliceUpdate's (though fortunately, in a
way that doesn't matter for any existing code).
EndpointSliceCache was using the name "endpointInfo" to refer to two
different data types (most egregiously in addEndpoints(), which had a
variable named `endpoint` of type `*endpointInfo` and a variable named
`endpointInfo` of type `Endpoint`).
Continue using "endpointInfo" in places that refer to proxy.Endpoint /
BaseEndpointInfo, since that's consistent with other code, but rename
the local "cache of the Endpoints field of an EndpointSlice" type from
"endpointInfo" to "endpointData". Likewise, rename endpointSliceInfo
to endpointSliceData, for consistency.
Put the ServiceChangeTracker and EndpointsChangeTracker definitions at
the top of the files, and put the ServicePortMap and EndpointsMap
definitions before their methods.
(No code changes.)
Move the ServicePort/BaseServicePortInfo types to serviceport.go.
Move the Endpoint/BaseEndpointInfo types to endpoint.go.
To avoid confusion with the new filenames, rename service.go to
servicechangetracker.go and endpoints.go to endpointschangetracker.go.
(No code changes; this just moves some code from types.go and
services.go to serviceport.go, and some code from types.go and
endpoints.go to endpoint.go.)
(This would become an error rather than a warning once we try to move
this code to another file.)
Also rename an "ok" variable to "exists" since that what it really
means.
ServicePortMap.merge had a giant comment explaining its return value,
but nothing ever used that return value.
ServicePort had an InternalTrafficPolicy() method, but nothing used it
(because it was redundant with InternalPolicyLocal().)
