APPS-1063 Expose a flag to configure structured logging format

README.md

@@ -57,10 +57,11 @@ Usage:
   Use the following properties for service configuration [flags]
 
 Flags:
-  -c, --config string   configuration file path/URL
-  -h, --help            help for Use
-  -l, --log string      log level (default "DEBUG")
-  -v, --version         version for Use
+  -c, --config string       configuration file path/URL
+  -h, --help                help for Use
+  -f, --log-format string   log format (PLAIN, JSON) (default "PLAIN")
+  -l, --log-level string    log level (default "DEBUG")
+  -v, --version             version for Use
 ```
 
 ### Run

cmd/backup/main.go

@@ -29,7 +29,7 @@ var (
 // run parses the CLI parameters and executes backup.
 func run() int {
 	var (
-		configFile, logLevel string
+		configFile, logLevel, logFormat string
 	)
 
 	validateFlags := func(cmd *cobra.Command, args []string) error {
@@ -47,12 +47,13 @@ func run() int {
 	}
 
 	rootCmd.Flags().StringVarP(&configFile, "config", "c", "", "configuration file path/URL")
-	rootCmd.Flags().StringVarP(&logLevel, "log", "l", "DEBUG", "log level")
+	rootCmd.Flags().StringVarP(&logLevel, "log-level", "l", "DEBUG", "log level")
+	rootCmd.Flags().StringVarP(&logFormat, "log-format", "f", "PLAIN", "log format (PLAIN, JSON)")
 
 	rootCmd.RunE = func(cmd *cobra.Command, args []string) error {
-		slog.Info("Aerospike Backup Service", "commit", commit, "buildTime", buildTime)
 		// set default logger
-		slog.SetDefault(slog.New(util.LogHandler(logLevel)))
+		slog.SetDefault(slog.New(util.LogHandler(logLevel, logFormat)))
+		slog.Info("Aerospike Backup Service", "commit", commit, "buildTime", buildTime)
 		setConfigurationManager(configFile)
 		// read configuration file
 		config, err := readConfiguration()
@@ -65,15 +66,16 @@ func run() int {
 		schedulers := service.BuildBackupSchedulers(config)
 		service.ScheduleHandlers(ctx, schedulers)
 		// run HTTP server
-		return runHTTPServer(ctx, schedulers, config)
+		err = runHTTPServer(ctx, schedulers, config)
+		// shutdown shared resources
+		shared.Shutdown()
+		return err
 	}
 
 	err := rootCmd.Execute()
 	if err != nil {
 		slog.Error("Error in rootCmd.Execute", "err", err)
 	}
-	// shutdown shared resources
-	shared.Shutdown()
 
 	return util.ToExitVal(err)
 }

internal/util/util.go

@@ -13,11 +13,22 @@ import (
 
 // LogHandler returns the application log handler with the
 // configured level.
-func LogHandler(level string) slog.Handler {
-	return slog.NewTextHandler(os.Stdout, &slog.HandlerOptions{
-		Level:     logLevel(level),
-		AddSource: true,
-	})
+func LogHandler(level, format string) slog.Handler {
+	addSource := true
+	switch strings.ToUpper(format) {
+	case "PLAIN":
+		return slog.NewTextHandler(os.Stdout, &slog.HandlerOptions{
+			Level:     logLevel(level),
+			AddSource: addSource,
+		})
+	case "JSON":
+		return slog.NewJSONHandler(os.Stdout, &slog.HandlerOptions{
+			Level:     logLevel(level),
+			AddSource: addSource,
+		})
+	default:
+		panic(fmt.Sprintf("unsupported log format: %s", format))
+	}
 }
 
 // logLevel returns a level for the given string name.
@@ -35,7 +46,7 @@ func logLevel(level string) slog.Level {
 	case "ERROR":
 		return slog.LevelError
 	default:
-		panic(fmt.Sprintf("invalid log level configuration: %s", level))
+		panic(fmt.Sprintf("invalid log level: %s", level))
 	}
 }