Add support for service profiles created on external (non-service) authorities. For example, this allows you to create a service profile named `linkerd.io` which will apply to calls made to `linkerd.io`.
This is done by changing the `LINKERD2_PROXY_DESTINATION_PROFILE_SUFFIXES` to `.` so that the proxy will attempt to lookup a service profile for any authority. We provide the `--disable-external-profiles` proxy flag to revert this behavior in case it is a problem.
We also refactor the proxy-api implementation of GetProfiles so that it does the profile lookup, regardless of if the authority looks like a Kubernetes service name or not. To simplify this, support for multiple resolves (which was unused) was removed.
Signed-off-by: Alex Leong <alex@buoyant.io>
A container called `proxy-api` runs in the Linkerd2 controller pod. This container listens on port 8086 and serves the proxy-api but does nothing other than forward gRPC requests to the destination container which listens on port 8089.
We remove the proxy-api container altogether and change the destination container to listen on port 8086 instead of 8089. The result is that clients still use the proxy-api by connecting to `proxy-api.<ns>.svc.cluster.local:8086` but the controller has one fewer containers. This results in a simpler system that is easier to reason about.
Signed-off-by: Alex Leong <alex@buoyant.io>