feat(client): send logs to syslog (#2259)

client/cmd/root.go

@@ -121,7 +121,7 @@ func init() {
 	rootCmd.PersistentFlags().StringVarP(&serviceName, "service", "s", defaultServiceName, "Netbird system service name")
 	rootCmd.PersistentFlags().StringVarP(&configPath, "config", "c", defaultConfigPath, "Netbird config file location")
 	rootCmd.PersistentFlags().StringVarP(&logLevel, "log-level", "l", "info", "sets Netbird log level")
-	rootCmd.PersistentFlags().StringVar(&logFile, "log-file", defaultLogFile, "sets Netbird log path. If console is specified the log will be output to stdout")
+	rootCmd.PersistentFlags().StringVar(&logFile, "log-file", defaultLogFile, "sets Netbird log path. If console is specified the log will be output to stdout. If syslog is specified the log will be sent to syslog daemon.")
 	rootCmd.PersistentFlags().StringVarP(&setupKey, "setup-key", "k", "", "Setup key obtained from the Management Service Dashboard (used to register peer)")
 	rootCmd.PersistentFlags().StringVar(&preSharedKey, preSharedKeyFlag, "", "Sets Wireguard PreSharedKey property. If set, then only peers that have the same key can communicate.")
 	rootCmd.PersistentFlags().StringVarP(&hostName, "hostname", "n", "", "Sets a custom hostname for the device")

util/log.go

@@ -4,6 +4,7 @@ import (
 	"io"
 	"os"
 	"path/filepath"
+	"slices"
 
 	log "github.com/sirupsen/logrus"
 	"gopkg.in/natefinch/lumberjack.v2"
@@ -18,8 +19,9 @@ func InitLog(logLevel string, logPath string) error {
 		log.Errorf("Failed parsing log-level %s: %s", logLevel, err)
 		return err
 	}
+	custom_outputs := []string{"console", "syslog"};
 
-	if logPath != "" && logPath != "console" {
+	if logPath != "" && !slices.Contains(custom_outputs, logPath) {
 		lumberjackLogger := &lumberjack.Logger{
 			// Log file absolute path, os agnostic
 			Filename:   filepath.ToSlash(logPath),
@@ -29,6 +31,8 @@ func InitLog(logLevel string, logPath string) error {
 			Compress:   true,
 		}
 		log.SetOutput(io.Writer(lumberjackLogger))
+	} else if logPath == "syslog" {
+		AddSyslogHook()
 	}
 
 	if os.Getenv("NB_LOG_FORMAT") == "json" {

util/syslog_nonwindows.go

@@ -0,0 +1,20 @@
+//go:build !windows
+// +build !windows
+
+package util
+
+import (
+	"log/syslog"
+
+	log "github.com/sirupsen/logrus"
+	lSyslog "github.com/sirupsen/logrus/hooks/syslog"
+)
+
+func AddSyslogHook() {
+	hook, err := lSyslog.NewSyslogHook("", "", syslog.LOG_INFO, "")
+
+	if err != nil {
+		log.Errorf("Failed creating syslog hook: %s", err)
+	}
+	log.AddHook(hook)
+}

util/syslog_windows.go

@@ -0,0 +1,3 @@
+package util
+
+func AddSyslogHook() {}