Simple logger that listens for UNIX datagram message and prints them to stdout. We don't like syslog-ng in our postfix container!

logger.go

package main

import (
	"bufio"
	"net"
	"os"
	"syscall"
)

func println(msg string) {
	os.Stdout.WriteString(msg + "\n")
}

func main() {
	socketPath := "/dev/log"

	// unlink it before doing anything
	syscall.Unlink(socketPath)

	// resolve unix address
	laddr, err := net.ResolveUnixAddr("unixgram", socketPath)
	if err != nil {
		println("Could not resolve unix socket: " + err.Error())
		os.Exit(1)
	}

	// listen on the socket
	conn, err := net.ListenUnixgram("unixgram", laddr)
	if err != nil {
		println("Could not listen on unix socket datagram: " + err.Error())
		os.Exit(1)
	}
	// close socket when we finish
	defer conn.Close()

	// scan text
	scanner := bufio.NewScanner(conn)
	for {
		if ok := scanner.Scan(); !ok {
			continue
		}
		println(string(scanner.Bytes()))
	}
}