[vvoytovych]

The controller package's envtest tests started an API server for nearly every test, about 180 times, and the starts and stops took over half of the package's time (#837): 1062 s locally on main at 202bbf0a, and 1131–1170 s in the required check against its 20-minute test timeout. The package already shares two API servers, the planes, between the projection tests. Every test on the same CRDs, NSO's and the locations', now uses them: they start at first use and TestMain stops them, as kubebuilder's suite_test.go starts one environment for a package. The package now takes 155–161 s locally and 164 s in CI, against 1232 s on main, so go test takes Go's default timeout of 10 minutes again.

Changes

change	file
The planes and TestMain move to the package's suite file. planes also gives each server's config	suite_test.go, networkinterface_projection_test.go
startNetworkInterfaceEnv and the network service, repoint and connector lease tests use the first plane	networkinterfaceclaim_controller_test.go, networkservice_controller_test.go, connectoradvertisement_repoint_test.go, connector_lease_watch_test.go
A name that a scenario takes from its test's name comes from scenarioSuffix. It cuts the name to fit and adds a number that no other scenario in the test binary holds. It replaces 16 copies of sanitizeName(strings.ToLower(t.Name())) and the repoint tests' own counter	the scenario helpers and tests
A test deletes the cluster-scoped objects it writes: the cell's ServingLocation and a Location	networkinterface_controller_test.go, subnet_controller_test.go
The load balancer intent test lists only its own hub namespace	networkloadbalancercellintent_controller_test.go
The connector lease test's manager skips the controller name check, as the other manager tests do	connector_lease_watch_test.go
go test takes Go's default timeout again. The package outgrew it, so d063dc42 raised it to 20 minutes and #845 to 25. The flag and its comments go	.github/workflows/ci.yaml, Makefile

Corner cases

case	what happens	proof
Two tests whose names start the same	Their names differ. On main the presence scenario cuts names at 48 characters, so on one server the restart tests' subtests would get the same namespace	TestScenarioSuffixesAreUniqueAndFit
A test run twice in one process (-count)	Its second run gets new names	the same test; the package passes with -count=2
A test that delivers the cell's ServingLocation	The ServingLocation is deleted after the test. One delivered ServingLocation wins over the configured location, so it would change the location of every later test on the plane	the three tests that deliver one, run together
A test that fails part way	Its namespaces stay, under names that no later test takes. Its cleanups still run	named, not tested
A run without envtest's binaries	The tests skip, as before	sharedPlanes
A plane that fails to start	Every test that needs it fails with the start error	sync.OnceValues keeps the error

Not changed

• The Gateway API tests keep their own servers, 10 starts. Their CRDs are different. TestEnsureDownstreamGatewayHTTPRoutesStatusFitsInstalledSchema rewrites the HTTPRoute CRD during the test, and TestDownstreamClientTrafficPolicyWithoutTheKind needs Envoy Gateway's kinds to be absent. The other eight could share a third server and save about 30 s. But the five DNS tests run a manager over the whole server, with fixed names and hostnames in default, so that is a separate change.
• No test runs in parallel that did not before.

Test plan

• The package passes in 155, 161 and 161 s locally, 10 cores, one run at a time. main took 1062 s.
• With -count=2 -shuffle=on, all tests pass except TestHTTPProxyReconcileInternalErrorGetsStableFixedMessage. That test uses only fake clients, and it fails the same way on main under -shuffle (2 of 8 seeds). The HTTPProxy programming tracker's recorded map is global to the package and keeps a key that another test programmed.
• A planted defect per corner case turns its test red, 7 of 7, and so do the plants from fix: Give up a network's kept interfaces when the network is deleted #828, fix: Name a cell's network contexts from the location it serves #833, fix: Bring back every network presence when the controller starts #844 and fix: Hear a network's deletion at once where no binding declares it #846 that apply to today's main, 43 of 43. Each touched function's complexity is the same or lower, and golangci-lint passes.
• ci / Build and test finishes with every package inside Go's default 10 minutes. At d5594715 it took 8 min 14 s, with the controller package at 186 s, and at bb7222fc 5 min 31 s with it at 164 s. On main it takes 24 min 27 s.

Refs #837