Corrected implementation using coreOS systemd library

llama-swap.go

@@ -10,12 +10,11 @@ import (
 	"os"
 	"os/signal"
 	"path/filepath"
-	"strconv"
 	"syscall"
 	"time"
-
 	"github.com/fsnotify/fsnotify"
 	"github.com/gin-gonic/gin"
+	"github.com/coreos/go-systemd/v22/activation"
 	"github.com/mostlygeek/llama-swap/event"
 	"github.com/mostlygeek/llama-swap/proxy"
 	"github.com/mostlygeek/llama-swap/proxy/config"
@@ -68,30 +67,17 @@ func main() {
 	}
 	// Check for systemd socket activation
 	var listener net.Listener
-    	listenFdsStr := os.Getenv("LISTEN_FDS")
-    	if listenFdsStr != "" {
-		listenFds, err := strconv.Atoi(listenFdsStr)
-		if err != nil {
-	    		log.Fatal("Failed to parse LISTEN_FDS:", err)
+	files, err := activation.Listeners()
+	if err != nil {
+		log.Fatalf("Systemd activation error: %v", err)
+	}
+	if len(files) > 0 {
+		if len(files) > 1 {
+			log.Fatalf("Expected a single activated socket, got %d", len(files))
 		}
-		if listenFds > 0 {
-	    		// The first socket is on FD 3
-	    		fd := 3
-	    		f := os.NewFile(uintptr(fd), "systemd socket")
-	    		if f == nil {
-				log.Fatal("Failed to get file descriptor")
-	    		}
-	    		listener, err = net.FileListener(f)
-	    		if err != nil {
-				log.Fatal("Failed to create listener:", err)
-	    		}
-	    		// The listener now owns the file, so we don't close it here.
-		} else {
-	    		log.Fatal("LISTEN_FDS is set but no sockets are passed")
-		}
-    	} else {
-	
-
+		listener = files[0]
+		log.Printf("Using systemd socket %s", listener.Addr())
+	} else {
 		// Set default ports.
 		if *listenStr == "" {
 			defaultPort := ":8080"
@@ -105,6 +91,8 @@ func main() {
         		}
 		}
 	}
+	defer listener.Close()
+
 	// Setup channels for server management
 	exitChan := make(chan struct{})
 	sigChan := make(chan os.Signal, 1)