Introduce foreigner network (#25)

* support network identity for instance

* introduce foreign network

foreign network allow a node serving as one public node. other nodes can
connect to this node to discover peers and exchange route info.

easytier-core/src/connector/manual.rs

@@ -220,8 +220,8 @@ impl ManualConnectorManager {
                 log::warn!("peer conn removed: {:?}", conn_info);
             }
 
-            GlobalCtxEvent::PeerAdded => todo!(),
-            GlobalCtxEvent::PeerRemoved => todo!(),
+            GlobalCtxEvent::PeerAdded(..) => todo!(),
+            GlobalCtxEvent::PeerRemoved(..) => todo!(),
         }
     }
 

easytier-core/src/connector/udp_hole_punch.rs

@@ -499,12 +499,18 @@ pub mod tests {
         }
     }
 
+    pub fn replace_stun_info_collector(peer_mgr: Arc<PeerManager>, udp_nat_type: NatType) {
+        let collector = Box::new(MockStunInfoCollector { udp_nat_type });
+        peer_mgr
+            .get_global_ctx()
+            .replace_stun_info_collector(collector);
+    }
+
     pub async fn create_mock_peer_manager_with_mock_stun(
         udp_nat_type: NatType,
     ) -> Arc<PeerManager> {
         let p_a = create_mock_peer_manager().await;
-        let collector = Box::new(MockStunInfoCollector { udp_nat_type });
-        p_a.get_global_ctx().replace_stun_info_collector(collector);
+        replace_stun_info_collector(p_a.clone(), udp_nat_type);
         p_a
     }