Integrate relay into peer conn

- extend mgm with relay address
- extend signaling with remote peer's relay address
- start setup relay connection before engine start

management/proto/management.proto

@@ -146,6 +146,8 @@ message WiretrusteeConfig {
 
   // a Signal server config
   HostConfig signal = 3;
+
+  string RelayAddress = 4;
 }
 
 // HostConfig describes connection properties of some server (e.g. STUN, Signal, Management)

management/server/config.go

@@ -32,9 +32,10 @@ const (
 
 // Config of the Management service
 type Config struct {
-	Stuns      []*Host
-	TURNConfig *TURNConfig
-	Signal     *Host
+	Stuns        []*Host
+	TURNConfig   *TURNConfig
+	RelayAddress string
+	Signal       *Host
 
 	Datadir                string
 	DataStoreEncryptionKey string

management/server/grpcserver.go

@@ -450,6 +450,7 @@ func toWiretrusteeConfig(config *Config, turnCredentials *TURNCredentials) *prot
 			Uri:      config.Signal.URI,
 			Protocol: ToResponseProto(config.Signal.Proto),
 		},
+		RelayAddress: config.RelayAddress,
 	}
 }