Found the connection issue if we change the port from 8083 to another port in the test TestBasicConfigLegacy(#117). It seems to only happen in the CI, cannot repro in my local env.

The error:

Error:		Received unexpected error "rpc error: code = Unavailable desc = all SubConns are in TransientFailure, latest connection error: connection error: desc = \"transport: Error while dialing dial tcp 127.0.0.1:8093: connect: connection refused\""

IMO, about the reason why the original port 8083 works, it is related to the port 8083 has been opened before in other tests(https://github.com/lyft/ratelimit/blob/c4f75a8e3f2671c81764d55d5e0b08b92e4a11df/test/integration/integration_test.go#L45).