Fix #202

README.md

@@ -377,6 +377,7 @@ A built-in HTTP server listens on port `8000` to modify the state of the contain
 
 - `http://<your-docker-host-ip>:8000/openvpn/actions/restart` restarts the openvpn process
 - `http://<your-docker-host-ip>:8000/unbound/actions/restart` re-downloads the DNS files (crypto and block lists) and restarts the unbound process
+- `http://<your-docker-host-ip>:8000/openvpn/portforwarded` to get your port forwarded as JSON. You can use **jq** to parse JSON on linux.
 
 ## Development and contributing
 

cmd/gluetun/main.go

@@ -129,6 +129,7 @@ func _main(background context.Context, args []string) int {
 		ovpnConf, firewallConf, logger, client, fileManager, streamMerger, fatalOnError)
 	restartOpenvpn := openvpnLooper.Restart
 	portForward := openvpnLooper.PortForward
+	getPortForwarded := openvpnLooper.GetPortForwarded
 	// wait for restartOpenvpn
 	go openvpnLooper.Run(ctx, wg)
 
@@ -176,7 +177,7 @@ func _main(background context.Context, args []string) int {
 		}
 	}()
 
-	httpServer := server.New("0.0.0.0:8000", logger, restartOpenvpn, restartUnbound)
+	httpServer := server.New("0.0.0.0:8000", logger, restartOpenvpn, restartUnbound, getPortForwarded)
 	go httpServer.Run(ctx, wg)
 
 	// Start openvpn for the first time

internal/openvpn/loop.go

@@ -23,13 +23,16 @@ type Looper interface {
 	PortForward()
 	GetSettings() (settings settings.OpenVPN)
 	SetSettings(settings settings.OpenVPN)
+	GetPortForwarded() (portForwarded uint16)
 }
 
 type looper struct {
 	// Variable parameters
-	provider      models.VPNProvider
-	settings      settings.OpenVPN
-	settingsMutex sync.RWMutex
+	provider           models.VPNProvider
+	settings           settings.OpenVPN
+	settingsMutex      sync.RWMutex
+	portForwarded      uint16
+	portForwardedMutex sync.RWMutex
 	// Fixed parameters
 	uid int
 	gid int
@@ -187,11 +190,14 @@ func (l *looper) portForward(ctx context.Context, providerConf provider.Provider
 		port, err = providerConf.GetPortForward(client)
 		if err != nil {
 			l.logAndWait(ctx, err)
-			continue
 		}
-		l.logger.Info("port forwarded is %d", port)
 	}
 
+	l.logger.Info("port forwarded is %d", port)
+	l.portForwardedMutex.Lock()
+	l.portForwarded = port
+	l.portForwardedMutex.Unlock()
+
 	filepath := settings.Provider.PortForwarding.Filepath
 	l.logger.Info("writing forwarded port to %s", filepath)
 	err = l.fileManager.WriteLinesToFile(
@@ -206,3 +212,9 @@ func (l *looper) portForward(ctx context.Context, providerConf provider.Provider
 		l.logger.Error(err)
 	}
 }
+
+func (l *looper) GetPortForwarded() (portForwarded uint16) {
+	l.portForwardedMutex.RLock()
+	defer l.portForwardedMutex.RUnlock()
+	return l.portForwarded
+}

internal/server/openvpn.go

@@ -0,0 +1,23 @@
+package server
+
+import (
+	"encoding/json"
+	"net/http"
+)
+
+func (s *server) handleGetPortForwarded(w http.ResponseWriter) {
+	port := s.getPortForwarded()
+	data, err := json.Marshal(struct {
+		Port uint16 `json:"port"`
+	}{port})
+	if err != nil {
+		s.logger.Warn(err)
+		w.WriteHeader(http.StatusInternalServerError)
+		return
+	}
+	if _, err := w.Write(data); err != nil {
+		s.logger.Warn(err)
+		w.WriteHeader(http.StatusInternalServerError)
+	}
+}
+

internal/server/server.go

@@ -15,18 +15,21 @@ type Server interface {
 }
 
 type server struct {
-	address        string
-	logger         logging.Logger
-	restartOpenvpn func()
-	restartUnbound func()
+	address          string
+	logger           logging.Logger
+	restartOpenvpn   func()
+	restartUnbound   func()
+	getPortForwarded func() uint16
 }
 
-func New(address string, logger logging.Logger, restartOpenvpn, restartUnbound func()) Server {
+func New(address string, logger logging.Logger, restartOpenvpn, restartUnbound func(),
+	getPortForwarded func() uint16) Server {
 	return &server{
-		address:        address,
-		logger:         logger.WithPrefix("http server: "),
-		restartOpenvpn: restartOpenvpn,
-		restartUnbound: restartUnbound,
+		address:          address,
+		logger:           logger.WithPrefix("http server: "),
+		restartOpenvpn:   restartOpenvpn,
+		restartUnbound:   restartUnbound,
+		getPortForwarded: getPortForwarded,
 	}
 }
 
@@ -61,6 +64,8 @@ func (s *server) makeHandler() http.HandlerFunc {
 				s.restartOpenvpn()
 			case "/unbound/actions/restart":
 				s.restartUnbound()
+			case "/openvpn/portforwarded":
+				s.handleGetPortForwarded(w)
 			default:
 				routeDoesNotExist(s.logger, w, r)
 			}