Syslog Hooks for Logrus

Usage

package main

import (
	"log/syslog"

	"github.com/sirupsen/logrus"
	lsyslog "github.com/sirupsen/logrus/hooks/syslog"
)

func main() {
	log := logrus.New()
	hook, err := lsyslog.NewSyslogHook("udp", "localhost:514", syslog.LOG_INFO, "")

	if err == nil {
		log.Hooks.Add(hook)
	}
}

If you want to connect to local syslog (Ex. "/dev/log" or "/var/run/syslog" or "/var/run/log"). Just assign empty string to the first two parameters of NewSyslogHook. It should look like the following.

package main

import (
	"log/syslog"

	"github.com/sirupsen/logrus"
	lsyslog "github.com/sirupsen/logrus/hooks/syslog"
)

func main() {
	log := logrus.New()
	hook, err := lsyslog.NewSyslogHook("", "", syslog.LOG_INFO, "")

	if err == nil {
		log.Hooks.Add(hook)
	}
}

Different log levels for local and remote logging

By default NewSyslogHook() sends logs through the hook for all log levels. If you want to have different log levels between local logging and syslog logging (i.e., respect the priority argument passed to NewSyslogHook()), you need to define a custom hook type that satisfies the logrus.Hook interface by embedding *lsyslog.SyslogHook and overriding Levels() to return only the log levels you're interested in.

The following example shows how to log at DEBUG level for local logging and WARN level for syslog logging:

package main

import (
	"log/syslog"

	log "github.com/sirupsen/logrus"
	lsyslog "github.com/sirupsen/logrus/hooks/syslog"
)

type customHook struct {
	*lsyslog.SyslogHook
}

func (h *customHook) Levels() []log.Level {
	return []log.Level{log.WarnLevel}
}

func main() {
	log.SetLevel(log.DebugLevel)

	hook, err := lsyslog.NewSyslogHook("tcp", "localhost:5140", syslog.LOG_WARNING, "myTag")
	if err != nil {
		panic(err)
	}

	log.AddHook(&customHook{hook})

	// ...
}