Add option for setting the logging format

config.scfg

@@ -5,6 +5,8 @@ base-url https://ntfy-alertmanager.xenrox.net
 http-address :8080
 # Log level (either debug, info, warning, error)
 log-level info
+# Log format (either text or json)
+log-format text
 # When multiple alerts are grouped together by Alertmanager, they can either be sent
 # each on their own (single mode) or be kept together (multi mode) (either single or multi; default is multi)
 alert-mode single

config/config.go

@@ -24,6 +24,7 @@ type Config struct {
 	BaseURL     string
 	HTTPAddress string
 	LogLevel    string
+	LogFormat   string
 	AlertMode   AlertMode
 	User        string
 	Password    string
@@ -90,6 +91,7 @@ func ReadConfig(path string) (*Config, error) {
 	// Set default values
 	config.HTTPAddress = "127.0.0.1:8080"
 	config.LogLevel = "info"
+	config.LogFormat = "text"
 	config.AlertMode = Multi
 
 	config.Cache.Type = "disabled"
@@ -106,6 +108,13 @@ func ReadConfig(path string) (*Config, error) {
 		}
 	}
 
+	d = cfg.Get("log-format")
+	if d != nil {
+		if err := d.ParseParams(&config.LogFormat); err != nil {
+			return nil, err
+		}
+	}
+
 	d = cfg.Get("http-address")
 	if d != nil {
 		if err := d.ParseParams(&config.HTTPAddress); err != nil {

config/config_test.go

@@ -13,6 +13,7 @@ func TestReadConfig(t *testing.T) {
 base-url https://ntfy-alertmanager.xenrox.net
 http-address :8080
 log-level info
+log-format json
 alert-mode multi
 user webhookUser
 password webhookPass
@@ -66,6 +67,7 @@ cache {
 		BaseURL:     "https://ntfy-alertmanager.xenrox.net",
 		HTTPAddress: ":8080",
 		LogLevel:    "info",
+		LogFormat:   "json",
 		AlertMode:   Multi,
 		User:        "webhookUser",
 		Password:    "webhookPass",

main.go

@@ -453,24 +453,19 @@ func main() {
 		os.Exit(0)
 	}
 
-	logLevel := new(slog.LevelVar)
-	logger := slog.New(slog.NewTextHandler(os.Stderr, &slog.HandlerOptions{
-		Level: logLevel,
-	}))
-
 	cfg, err := config.ReadConfig(configPath)
 	if err != nil {
-		logger.Error("Failed to read config",
+		slog.Error("Failed to read config",
 			slog.String("error", err.Error()))
 		os.Exit(1)
 	}
 
-	level, err := logging.ParseLevelFromString(cfg.LogLevel)
+	logger, err := logging.New(cfg.LogLevel, cfg.LogFormat, os.Stderr)
 	if err != nil {
-		logger.Error("Failed to parse logging level",
+		slog.Error("Failed to create logger",
 			slog.String("error", err.Error()))
+		os.Exit(1)
 	}
-	logLevel.Set(level)
 
 	ctx, stop := signal.NotifyContext(context.Background(), syscall.SIGINT, syscall.SIGTERM)
 	defer stop()