Merge pull request #4 from mechmind/shutdown

Add ability to shut down a server

Author: lunny

server.go

@@ -53,6 +53,7 @@ type Server struct {
 	listenTo      string
 	driverFactory DriverFactory
 	logger        *Logger
+	listener      net.Listener
 }
 
 // serverOptsWithDefaults copies an ServerOpts struct into a new struct,
@@ -191,15 +192,17 @@ func (Server *Server) ListenAndServe() error {
 
 	Server.logger.Printf("%s listening on %d", Server.Name, Server.Port)
 
+	Server.listener = listener
 	for {
-		tcpConn, err := listener.Accept()
+		tcpConn, err := Server.listener.Accept()
 		if err != nil {
-			Server.logger.Print("listening error")
+			Server.logger.Printf("listening error: %v", err)
 			break
 		}
 		driver, err := Server.driverFactory.NewDriver()
 		if err != nil {
-			Server.logger.Print("Error creating driver, aborting client connection")
+			Server.logger.Printf("Error creating driver, aborting client connection: %v", err)
+			tcpConn.Close()
 		} else {
 			ftpConn := Server.newConn(tcpConn, driver, Server.Auth)
 			go ftpConn.Serve()
@@ -208,6 +211,15 @@ func (Server *Server) ListenAndServe() error {
 	return nil
 }
 
+// Gracefully stops a server. Already connected clients will retain their connections
+func (Server *Server) Shutdown() error {
+	if Server.listener != nil {
+		return Server.listener.Close()
+	}
+	// server wasnt even started
+	return nil
+}
+
 func buildTcpString(hostname string, port int) (result string) {
 	if strings.Contains(hostname, ":") {
 		// ipv6