Add better logging and a debug mode.

docker-compose.yml

@@ -9,6 +9,7 @@ services:
       - PB_LISTENBRAINZ_USER_TOKEN=token
       - PB_PLEX_USERNAME=someusernamehere
       - PB_PLEX_LIBRARIES=Music
+      - PB_DEBUG=false
     ports:
       - 9102:9102
     restart: unless-stopped

main.go

@@ -5,9 +5,10 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
-	"log"
+	"log/slog"
 	"net/http"
 	"os"
+	"strconv"
 	"strings"
 	"time"
 )
@@ -22,17 +23,25 @@ func main() {
 	lbToken = os.Getenv("PB_LISTENBRAINZ_USER_TOKEN")
 	plexUsername = os.Getenv("PB_PLEX_USERNAME")
 	plexLibsStr = os.Getenv("PB_PLEX_LIBRARIES")
+	debug, _ := strconv.ParseBool(os.Getenv("PB_DEBUG"))
 
 	if lbToken == "" {
-		log.Fatal("you must set PB_LISTENBRAINZ_USER_TOKEN - see https://listenbrainz.org/settings/")
+		slog.Error("you must set PB_LISTENBRAINZ_USER_TOKEN - see https://listenbrainz.org/settings/")
+		os.Exit(1)
 	}
 
 	if plexUsername == "" {
-		log.Fatal("you must set PB_PLEX_USERNAME to the user who's listens will be recorded")
+		slog.Error("you must set PB_PLEX_USERNAME to the user who's listens will be recorded")
+		os.Exit(1)
 	}
 
 	if plexLibsStr == "" {
-		log.Fatal("you must set PB_PLEX_LIBRARIES to a comma separated list of plex libraries which will be scrobbled")
+		slog.Error("you must set PB_PLEX_LIBRARIES to a comma separated list of plex libraries which will be scrobbled")
+		os.Exit(1)
+	}
+
+	if debug {
+		slog.SetLogLoggerLevel(slog.LevelDebug)
 	}
 
 	plexLibs := strings.Split(plexLibsStr, ",")
@@ -40,7 +49,7 @@ func main() {
 	http.HandleFunc("POST /plex", func(w http.ResponseWriter, r *http.Request) {
 		err := r.ParseMultipartForm(1 * 1024 * 1024)
 		if err != nil {
-			log.Printf("error parsing multipart form: %s", err.Error())
+			slog.Error("error parsing multipart form", "error", err.Error())
 			return
 		}
 
@@ -49,18 +58,18 @@ func main() {
 		err = json.Unmarshal([]byte(pl), &event)
 
 		if err != nil {
-			log.Printf("error parsing JSON: %s", err.Error())
+			slog.Error("error parsing JSON", "error", err.Error())
 			w.WriteHeader(400)
 			w.Write([]byte("could not parse your JSON"))
 			return
 		}
 
-		// log.Printf("event: %s", event.Event)
+		slog.Debug("received event", "event", event)
-		// log.Printf("account name: %s", event.Account.Title)
+		// slog.Printf("account name: %s", event.Account.Title)
-		// log.Printf("title: %s", event.Metadata.Title)
+		// slog.Printf("title: %s", event.Metadata.Title)
-		// log.Printf("album: %s", event.Metadata.ParentTitle)
+		// slog.Printf("album: %s", event.Metadata.ParentTitle)
-		// log.Printf("artist: %s", event.Metadata.GrandparentTitle)
+		// slog.Printf("artist: %s", event.Metadata.GrandparentTitle)
-		// log.Printf("library: %s", event.Metadata.LibrarySectionTitle)
+		// slog.Printf("library: %s", event.Metadata.LibrarySectionTitle)
 
 		// 2025/10/19 09:21:31 event: media.play
 		// 2025/10/19 09:21:31 account name: username
@@ -69,7 +78,7 @@ func main() {
 		// 2025/10/19 09:21:31 artist: Daft Punk
 		// 2025/10/19 09:21:31 library: Music
 		if event.Account.Title != plexUsername {
-			log.Printf("not scrobbling for user '%s'", plexUsername)
+			slog.Error("not scrobbling for this user", "user", event.Account.Title)
 			w.WriteHeader(200)
 			w.Write([]byte("ok"))
 			return
@@ -84,8 +93,8 @@ func main() {
 				}
 			}
 			if !found {
-				log.Printf("not scrobbling for library '%s'", event.Metadata.LibrarySectionTitle)
+				slog.Debug("not scrobbling for this library", "library", event.Metadata.LibrarySectionTitle)
-				log.Printf("does not match one of: '%s'", plexLibsStr)
+				slog.Debug("does not match a configured library", "libraries", plexLibsStr)
 				w.WriteHeader(200)
 				w.Write([]byte("ok"))
 				return
@@ -93,26 +102,27 @@ func main() {
 
 			err = lbSubmit(event.Metadata.Title, event.Metadata.GrandparentTitle, event.Metadata.ParentTitle)
 			if err != nil {
-				log.Printf("error submitting: %s", err.Error())
+				slog.Error("error submitting to listenbrainz", "error", err.Error())
 				w.WriteHeader(400)
-				w.Write([]byte("could not parse your JSON"))
+				w.Write([]byte("could not submit to listenbrainz"))
 				return
 			} else {
-				log.Printf("scrobbled play of %s - %s", event.Metadata.GrandparentTitle, event.Metadata.Title)
+				slog.Info("scrobbled play", "grandparent", event.Metadata.GrandparentTitle, "title", event.Metadata.Title)
 				w.WriteHeader(200)
 				w.Write([]byte("ok"))
 				return
 			}
 		} else {
-			log.Printf("non scrobble event: %s", event.Event)
+			slog.Debug("non scrobble event", "event", event.Event)
 			w.WriteHeader(200)
 			w.Write([]byte("ok"))
 			return
 		}
 
 	})
-	log.Printf("starting web server on %s", listen)
+	slog.Info("starting web server", "listen", listen)
-	log.Fatal(http.ListenAndServe(listen, nil))
+	slog.Error(http.ListenAndServe(listen, nil).Error())
+	os.Exit(1)
 }
 
 func lbSubmit(title, artist, album string) error {
@@ -161,7 +171,7 @@ func lbSubmit(title, artist, album string) error {
 	// happy path
 	resB := bytes.Buffer{}
 	io.Copy(&resB, res.Body)
-	log.Printf("listenbrainz OK - response: `%s`", resB.String())
+	slog.Debug("listenbrainz OK", "response", resB.String())
 
 	return nil
 }

structs.go

@@ -66,7 +66,7 @@ type webhookEvent struct {
 			Filter string `json:"filter"`
 			Tag    string `json:"tag"`
 		} `json:"Genre"`
-		GUID0 []struct {
+		OtherGUID []struct {
 			ID string `json:"id"`
 		} `json:"Guid"`
 		Mood []struct {