The destination controller's cluster store registers a gague in its constructor. When this constructor is called multiple times (i.e. in tests), this can lead to a panic.
To avoid this panic, this change updates NewClusterStoreWithDecoder to accept a prometheus registry). The NewClusterStore constructor (used by the application's main) continues to use the default registry, but tests now construct their own temporary registries to avoid duplicate registration errors.
Services in dual-stack mode result in the creation of two EndpointSlices, one for each IP family. Before this change, the Get Destination API would nondeterministically return the address for any of those ES, depending on which one was processed last by the controller because they would overwrite each other.
As part of the ongoing effort to support IPv6/dual-stack networks, this change fixes that behavior giving preference to IPv6 addresses whenever a service exposes both families.
There are a new set of unit tests in server_ipv6_test.go, and in the TestEndpointTranslatorForPods tests there's a couple of new cases to test the interaction with zone filtering.
Also the server unit tests were updated to segregate the tests and resources dealing with the IPv4/IPv6/dual-stack cases.
Oliver Gould
Alejandro Pedraza