And use the fake interface in the unit tests, removing the dependency
on setting up FakeExec stuff when conntrack cleanup will be invoked.
Also, remove the isIPv6 argument to CleanStaleEntries, because it can
be inferred from the other args.
The iptables and nftables proxy backends had 2 unit tests
(TestDeleteEndpointConnections and TestProxierDeleteNodePortStaleUDP)
that were effectively testing that:
- If the proxy saw various Service/EndpointSlice events this would
result in specific changes to the service/endpoints trackers, AND
- If the service/endpoints trackers changed in those specific ways
this would result in specific UpdateServiceMapResult and
UpdateEndpointsMapResult values being generated, AND
- If you passed those specific UpdateServiceMapResult and
UpdateEndpointsMapResult values to conntrack.CleanStaleEntries it
would make specific calls to the lower-level conntrack methods,
AND
- If you called the lower-level conntrack methods with those
specific arguments, it would result in specific executions of the
conntrack binary, mixed with a specific number of klog
invocations.
This... is not a good unit test. We already test the change tracker
behavior in other unit tests, and we already tested the
Update{Service,Endpoints}MapResult behavior in the pkg/proxy unit
tests, and we already tested the conntrack exec behavior in
pkg/proxy/conntrack/conntrack_test.go, and we now test the
CleanStaleEntries behavior in pkg/proxy/conntrack/cleanup_test.go. So
there is no need to try to test the top-to-bottom behavior as a "unit
test".
Add an interface between CleanStaleEntries and the lower-level
conntrack helpers (ClearEntriesForIP, etc), and a fake implementation
of that interface, so that we can explicitly test CleanStaleEntries's
logic.
Remove some comments from conntrack.go that were explaining the
functions' callers rather than explaining the functions themselves
(and which were redundant with other comments in the callers anyway).
