Fixes an RPC client goroutine leak by properly closing the underlying connection

infrastructure/network/rpcclient/grpcclient/grpcclient.go

@@ -22,6 +22,7 @@ type OnDisconnectedHandler func()
 // GRPCClient is a gRPC-based RPC client
 type GRPCClient struct {
 	stream                protowire.RPC_MessageStreamClient
+	connection            *grpc.ClientConn
 	onErrorHandler        OnErrorHandler
 	onDisconnectedHandler OnDisconnectedHandler
 }
@@ -43,7 +44,12 @@ func Connect(address string) (*GRPCClient, error) {
 	if err != nil {
 		return nil, errors.Wrapf(err, "error getting client stream for %s", address)
 	}
-	return &GRPCClient{stream: stream}, nil
+	return &GRPCClient{stream: stream, connection: gRPCConnection}, nil
+}
+
+// Close closes the underlying grpc connection
+func (c *GRPCClient) Close() error {
+	return c.connection.Close()
 }
 
 // Disconnect disconnects from the RPC server

infrastructure/network/rpcclient/rpcclient.go

@@ -143,6 +143,9 @@ func (c *RPCClient) handleClientDisconnected() {
 }
 
 func (c *RPCClient) handleClientError(err error) {
+	if atomic.LoadUint32(&c.isClosed) == 1 {
+		return
+	}
 	log.Warnf("Received error from client: %s", err)
 	c.handleClientDisconnected()
 }
@@ -159,7 +162,7 @@ func (c *RPCClient) Close() error {
 		return errors.Errorf("Cannot close a client that had already been closed")
 	}
 	c.rpcRouter.router.Close()
-	return nil
+	return c.GRPCClient.Close()
 }
 
 // Address returns the address the RPC client connected to