Support listening on unix socket

main.go

@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"io"
 	"log"
+	"net"
 	"net/http"
 	"os"
 	"path"
@@ -29,13 +30,19 @@ func main() {
 		log.Panicln("CHKBOT_API_TOKEN is empty")
 	}
 
-	port := func() int {
+	port, unixSocketPath := func() (int, string) {
 		portStr := os.Getenv("CHKBOT_PORT")
 
-		if port, err := strconv.Atoi(portStr); err == nil {
-			return port
+		defaultPort := 28923
+
+		if strings.HasPrefix(portStr, "unix/") {
+			return defaultPort, strings.TrimPrefix(portStr, "unix/")
 		}
-		return 28923
+
+		if port, err := strconv.Atoi(portStr); err == nil {
+			return port, ""
+		}
+		return defaultPort, ""
 	}()
 
 	dataPath := func() string {
@@ -45,7 +52,7 @@ func main() {
 		}
 
 		if err := os.MkdirAll(dataPath, 0755); err != nil {
-			log.Panicf("Failed to create datapath, path: %s, err: %s\n", dataPath, err)
+			log.Panicf("Failed to create datapath, path: %q, err: %s\n", dataPath, err)
 		}
 		return dataPath
 	}()
@@ -63,7 +70,14 @@ func main() {
 		return "unknown"
 	}()
 
-	log.Printf("Grocery List bot (%s) starting with datapath:%s, port:%d\n", commit, dataPath, port)
+	listeningOn := func() string {
+		if unixSocketPath != "" {
+			return fmt.Sprintf("socket: %q", unixSocketPath)
+		}
+		return fmt.Sprintf("port: %v", port)
+	}()
+
+	log.Printf("Grocery List bot (%s) starting with datapath: %q, %s\n", commit, dataPath, listeningOn)
 
 	var chats sync.Map
 	if err := loadData(dataPath, &chats); err != nil {
@@ -123,7 +137,7 @@ func main() {
 			chatID := update.CallbackQuery.Message.Chat.ID
 			g, ok := chats.Load(chatID)
 			if !ok {
-				log.Printf("Chat not found: %d\n", chatID)
+				log.Printf("Chat not found: %v\n", chatID)
 				return
 			}
 			gl := g.(*glist.GList)
@@ -131,6 +145,13 @@ func main() {
 
 		}
 	})
+	if unixSocketPath != "" {
+		l, err := net.Listen("unix", unixSocketPath)
+		if err != nil {
+			log.Panicf("Unable to listen to unix socket in path: %q err:%v\n", unixSocketPath, err)
+		}
+		log.Panicln(http.Serve(l, nil))
+	}
 	log.Panicln(http.ListenAndServe(fmt.Sprintf(":%v", port), nil))
 }
 
@@ -276,11 +297,11 @@ func loadData(dataPath string, chats *sync.Map) error {
 		var gl glist.GList
 		data, err := os.ReadFile(path.Join(dataPath, name))
 		if err != nil {
-			return fmt.Errorf("failed read file, name: %s, err:%w", name, err)
+			return fmt.Errorf("failed read file, name: %q, err:%w", name, err)
 		}
 		err = json.Unmarshal(data, &gl)
 		if err != nil {
-			return fmt.Errorf("failed to parse data, data:%s, err:%w", data, err)
+			return fmt.Errorf("failed to parse data, data:%q, err:%w", data, err)
 		}
 		chats.Store(gl.ChatID, &gl)
 	}