fix(portforward): no longer stuck after failed port forwarding

internal/portforward/loop.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"net/http"
 	"sync"
+	"time"
 
 	"github.com/qdm12/gluetun/internal/configuration/settings"
 	"github.com/qdm12/gluetun/internal/portforward/service"
@@ -87,6 +88,8 @@ func (l *Loop) run(runCtx context.Context, runDone chan<- struct{},
 	defer close(runDone)
 
 	var serviceRunError <-chan error
+	var retryAfter <-chan time.Time
+	const retryDelay = 5 * time.Second
 	for {
 		updateReceived := false
 		select {
@@ -105,10 +108,12 @@ func (l *Loop) run(runCtx context.Context, runDone chan<- struct{},
 			l.settingsMutex.Unlock()
 		case err := <-serviceRunError:
 			l.logger.Error(err.Error())
+		case <-retryAfter:
+			// Retry starting the service after a delay
+			retryAfter = nil
 		}
 
-		firstRun := serviceRunError == nil
-		if !firstRun {
+		if l.service != nil {
 			err := l.service.Stop()
 			if err != nil {
 				runErrorCh <- fmt.Errorf("stopping previous service: %w", err)
@@ -132,6 +137,10 @@ func (l *Loop) run(runCtx context.Context, runDone chan<- struct{},
 				err = fmt.Errorf("starting port forwarding service: %w", err)
 			}
 			updateResult <- err
+		} else if err != nil {
+			// Log the error and schedule a retry
+			l.logger.Errorf("starting port forwarding service: %s - retrying in %s", err, retryDelay)
+			retryAfter = time.After(retryDelay)
 		}
 	}
 }