refactor(logger): remove lumberjack, use systemd journald for logging

README.md

@@ -196,3 +196,21 @@ alpamon.service - alpamon agent for Alpacon
      Loaded: loaded (/lib/systemd/system/alpamon.service; enabled; vendor preset: enabled)
      Active: active (running) since Thu 2023-09-28 23:48:55 KST; 4 days ago
 ```
+
+### Logs
+
+Alpamon logs are managed by systemd's journald. Use the following commands to view logs:
+
+```bash
+# View all logs
+journalctl -u alpamon
+
+# Follow logs in real-time
+journalctl -u alpamon -f
+
+# View logs since today
+journalctl -u alpamon --since today
+
+# View recent logs (last 100 lines)
+journalctl -u alpamon -n 100
+```

cmd/alpamon/command/root.go

@@ -20,7 +20,6 @@ import (
 	"github.com/alpacax/alpamon/pkg/version"
 	"github.com/rs/zerolog/log"
 	"github.com/spf13/cobra"
-	"gopkg.in/natefinch/lumberjack.v2"
 )
 
 const (
@@ -54,7 +53,7 @@ func runAgent() {
 	}()
 
 	// Logger
-	logRotate := logger.InitLogger()
+	logger.InitLogger()
 
 	// platform
 	utils.InitPlatform()
@@ -107,17 +106,17 @@ func runAgent() {
 		select {
 		case <-ctx.Done():
 			log.Info().Msg("Received termination signal. Shutting down...")
-			gracefulShutdown(metricCollector, wsClient, logRotate, logServer, pidFilePath)
+			gracefulShutdown(metricCollector, wsClient, logServer, pidFilePath)
 			return
 		case <-wsClient.ShutDownChan:
 			log.Info().Msg("Shutdown command received. Shutting down...")
 			cancel()
-			gracefulShutdown(metricCollector, wsClient, logRotate, logServer, pidFilePath)
+			gracefulShutdown(metricCollector, wsClient, logServer, pidFilePath)
 			return
 		case <-wsClient.RestartChan:
 			log.Info().Msg("Restart command received. Restarting...")
 			cancel()
-			gracefulShutdown(metricCollector, wsClient, logRotate, logServer, pidFilePath)
+			gracefulShutdown(metricCollector, wsClient, logServer, pidFilePath)
 			restartAgent()
 			return
 		case <-wsClient.CollectorRestartChan:
@@ -142,7 +141,7 @@ func restartAgent() {
 	}
 }
 
-func gracefulShutdown(collector *collector.Collector, wsClient *runner.WebsocketClient, logRotate *lumberjack.Logger, logServer *logger.LogServer, pidPath string) {
+func gracefulShutdown(collector *collector.Collector, wsClient *runner.WebsocketClient, logServer *logger.LogServer, pidPath string) {
 	if collector != nil {
 		collector.Stop()
 	}
@@ -155,8 +154,5 @@ func gracefulShutdown(collector *collector.Collector, wsClient *runner.Websocket
 
 	log.Debug().Msg("Bye.")
 
-	if logRotate != nil {
-		_ = logRotate.Close()
-	}
 	_ = os.Remove(pidPath)
 }

configs/alpamon.service

@@ -9,8 +9,9 @@ WorkingDirectory=/var/lib/alpamon
 SELinuxContext=-unconfined_u:unconfined_r:unconfined_t:s0
 AppArmorProfile=-unconfined
 Restart=on-failure
-StandardOutput=null
-StandardError=null
+StandardOutput=journal
+StandardError=journal
+SyslogIdentifier=alpamon
 
 [Install]
 WantedBy=multi-user.target

go.mod

@@ -22,7 +22,6 @@ require (
 	golang.org/x/term v0.30.0
 	gopkg.in/go-playground/validator.v9 v9.31.0
 	gopkg.in/ini.v1 v1.67.0
-	gopkg.in/natefinch/lumberjack.v2 v2.2.1
 )
 
 require (

go.sum

@@ -150,8 +150,6 @@ gopkg.in/go-playground/validator.v9 v9.31.0 h1:bmXmP2RSNtFES+bn4uYuHT7iJFJv7Vj+a
 gopkg.in/go-playground/validator.v9 v9.31.0/go.mod h1:+c9/zcJMFNgbLvly1L1V+PpxWdVbfP1avr/N00E2vyQ=
 gopkg.in/ini.v1 v1.67.0 h1:Dgnx+6+nfE+IfzjUEISNeydPJh9AXNNsWbGP9KzCsOA=
 gopkg.in/ini.v1 v1.67.0/go.mod h1:pNLf8WUiyNEtQjuu5G5vTm06TEv9tsIgeAvK8hOrP4k=
-gopkg.in/natefinch/lumberjack.v2 v2.2.1 h1:bBRl1b0OH9s/DuPhuXpNl+VtCaJXFZ5/uEFST95x9zc=
-gopkg.in/natefinch/lumberjack.v2 v2.2.1/go.mod h1:YD8tP3GAjkrDg1eZH7EGmyESg/lsYskCTPBJVb9jqSc=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 modernc.org/cc/v4 v4.21.4 h1:3Be/Rdo1fpr8GrQ7IVw9OHtplU4gWbb+wNgeoBMmGLQ=

pkg/logger/logger.go

@@ -14,13 +14,10 @@ import (
 	"github.com/alpacax/alpamon/pkg/version"
 	"github.com/rs/zerolog"
 	"github.com/rs/zerolog/log"
-	"gopkg.in/natefinch/lumberjack.v2"
 )
 
 const (
-	logDir      = "/var/log/alpamon"
-	logFileName = "alpamon.log"
-	recordURL   = "/api/history/logs/"
+	recordURL = "/api/history/logs/"
 )
 
 type LogRecord struct {
@@ -54,35 +51,19 @@ var logRecordFileHandlers = map[string]int{
 	"server.go":  40, // logger/server.go
 }
 
-func InitLogger() *lumberjack.Logger {
-	fileName := fmt.Sprintf("%s/%s", logDir, logFileName)
-	if _, err := os.Stat(logDir); os.IsNotExist(err) {
-		fileName = logFileName
-	}
-
-	// Set up lumberjack logger for log rotation
-	logRotate := &lumberjack.Logger{
-		Filename:   fileName,
-		MaxSize:    50, // Max size in MB before rotation
-		MaxBackups: 5,  // Max number of backup files
-		MaxAge:     30, // Max age in days
-		Compress:   true,
-	}
-
+func InitLogger() {
 	recordWriter := &logRecordWriter{}
 
 	var output io.Writer
 	if version.Version == "dev" {
-		// In development, log to console with caller info
+		// In development, log to stderr with caller info
 		output = zerolog.MultiLevelWriter(PrettyWriter(os.Stderr, true), recordWriter)
 	} else {
-		// In production, log to file without caller info in PrettyWriter
-		output = zerolog.MultiLevelWriter(PrettyWriter(logRotate, false), recordWriter)
+		// In production, log to stderr without caller info (systemd/journald will capture)
+		output = zerolog.MultiLevelWriter(PrettyWriter(os.Stderr, false), recordWriter)
 	}
 	// Always include .Caller() so entry.Caller is set for logRecordWriter
 	log.Logger = zerolog.New(output).With().Timestamp().Caller().Logger()
-
-	return logRotate
 }
 
 // PrettyWriter returns a zerolog.ConsoleWriter with or without caller info