Add support for "syslog" logging

CHANGELOG.md

@@ -1,5 +1,7 @@
 ## v0.8.1 [unreleased]
 
+- [Issue #896](https://github.com/influxdb/influxdb/issues/896). Allow logging to syslog. Thanks @malthe
+
 ### Bugfixes
 
 ## v0.8.0 [2014-08-22]

config.sample.toml

@@ -18,7 +18,7 @@ reporting-disabled = false
 [logging]
 # logging level can be one of "debug", "info", "warn" or "error"
 level  = "info"
-file   = "influxdb.log"         # stdout to log to standard out
+file   = "influxdb.log"         # stdout to log to standard out, or syslog
 
 # Configure the admin server
 [admin]

daemon/influxd.go

@@ -31,11 +31,18 @@ func setupLogging(loggingLevel, logFile string) {
 
 	log.Global = make(map[string]*log.Filter)
 
-	if logFile == "stdout" {
+    switch logFile {
+    case "stdout":
 		flw := log.NewConsoleLogWriter()
 		log.AddFilter("stdout", level, flw)
-
-	} else {
+	case "syslog":
+		flw, err := NewSysLogWriter(3)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "NewSysLogWriter: %s\n", err.Error())
+			return
+		}
+		log.AddFilter("syslog", level, flw)
+	default:
 		logFileDir := filepath.Dir(logFile)
 		os.MkdirAll(logFileDir, 0744)
 
@@ -62,6 +69,7 @@ func main() {
 	pidFile := flag.String("pidfile", "", "the pid file")
 	repairLeveldb := flag.Bool("repair-ldb", false, "set to true to repair the leveldb files")
 	stdout := flag.Bool("stdout", false, "Log to stdout overriding the configuration")
+	syslog := flag.Bool("syslog", false, "Log to syslog overriding the configuration")
 
 	runtime.GOMAXPROCS(runtime.NumCPU())
 	flag.Parse()
@@ -96,6 +104,11 @@ func main() {
 	if *stdout {
 		config.LogFile = "stdout"
 	}
+
+	if *syslog {
+		config.LogFile = "syslog"
+	}
+
 	setupLogging(config.LogLevel, config.LogFile)
 
 	if *repairLeveldb {

daemon/syslog.go

@@ -0,0 +1,82 @@
+package main
+
+import (
+	"errors"
+	"log/syslog"
+
+	log "code.google.com/p/log4go"
+)
+
+// This log writer sends output to a socket
+type SysLogWriter chan *log.LogRecord
+
+// This is the SocketLogWriter's output method
+func (w SysLogWriter) LogWrite(rec *log.LogRecord) {
+	w <- rec
+}
+
+func (w SysLogWriter) Close() {
+	close(w)
+}
+
+func GetWriter(writer *syslog.Writer, level string) func(string) error {
+	switch level {
+	case "DEBG", "TRAC", "FINE", "FNST":
+		return writer.Debug
+	case "INFO":
+		return writer.Info
+	case "WARN":
+		return writer.Warning
+	case "EROR":
+		return writer.Err
+	default:
+		return writer.Crit
+	}
+}
+
+func Log(writer *syslog.Writer, level string, message string) {
+	m := GetWriter(writer, level)
+	m(message)
+}
+
+func connectSyslogDaemon() (writer *syslog.Writer, err error) {
+	logTypes := []string{"unixgram", "unix"}
+	logPaths := []string{"/dev/log", "/var/run/syslog"}
+	var raddr string
+	for _, network := range logTypes {
+		for _, path := range logPaths {
+			raddr = path
+			writer, err = syslog.Dial(network, raddr, syslog.LOG_SYSLOG, "influxdb")
+			if err != nil {
+				continue
+			} else {
+				return
+			}
+		}
+	}
+	if err != nil {
+		err = errors.New("cannot connect to Syslog Daemon")
+	}
+	return
+}
+
+
+func NewSysLogWriter(facility int) (w SysLogWriter, err error) {
+	writer, err := connectSyslogDaemon()
+	if err != nil {
+		return
+	}
+	w = SysLogWriter(make(chan *log.LogRecord, log.LogBufferLength))
+	go func() {
+		defer func() {
+			if w != nil {
+				w.Close()
+			}
+		}()
+		for rec := range w {
+			m := log.FormatLogRecord("(%S) %M", rec)
+			Log(writer, rec.Level.String(), m)
+		}
+	}()
+	return
+}

integration/migration_test.toml

@@ -18,7 +18,7 @@ reporting-disabled = true
 [logging]
 # logging level can be one of "debug", "info", "warn" or "error"
 level  = "info"
-file   = "stdout"         # stdout to log to standard out
+file   = "stdout"         # stdout to log to standard out, or syslog
 
 # Configure the admin server
 [admin]

integration/test_config_single.toml

@@ -18,7 +18,7 @@ reporting-disabled = true
 [logging]
 # logging level can be one of "debug", "info", "warn" or "error"
 level  = "info"
-file   = "stdout"         # stdout to log to standard out
+file   = "stdout"         # stdout to log to standard out, or syslog
 
 # Configure the admin server
 [admin]