Description

https://github.com/solo-io/solo-projects/issues/7105

This will make cluster names for kube services look like kube-svc_name_namespace_port or kube-svc_reviews_bookinfo_8080. If we add other resources besides a kube service, this also lets us get things like istio-se_helloworld_backend-ns_5000.

This will only happen for Gateway v2 translation. We can disable it using the env var GG_K8S_GW_LEGACY_CLUSTER_NAMES.

API changes

We can disable it using the env var GG_K8S_GW_LEGACY_CLUSTER_NAMES.

Code changes

XDS translator now takes options that can customize this new behavior. We instantiate translator separately for v2, so that is the only path to enable it.
Added another function to customize the generated name rather than modifying the existing cluster name function (it has over 100 usages! mostly in unit tests)
Use internal labels to propagate the info in a structured way.

Docs changes

We should document this as a breaking change; users who rely on the old format should use the env var or update their EnvoyFilters or whatever config relies on XDS names...

Context

https://github.com/solo-io/solo-projects/issues/7105

Interesting decisions

Use internal labels to propagate the info in a structured way. This was done so we can support more than just Upstream_Kube upstreams.
Functional options for translator constructor. I didn't feel like updating the many references to this constructor, so varargs help. In hindsight, a second constructor could have also solved this.