why

insanity.go

package main

import (
	"bufio"
	"encoding/json"
	"fmt"
	"log"
	"net"
	"os"
	"strings"
	"time"
)

const (
	ceeToken          = "@cee:"
	expectedLineParts = 2
	retryInterval     = 1
)

var (
	listenAddress = ":33333"
	listenProto   = "tcp"
	dialAddress   = "127.0.0.1:514"
	dialProto     = "tcp"
	oldChar       = "."
	newChar       = "_"
)

func main() {

	sendChan := make(chan string)

	go func() {
	AttemptToConnect:
		syslogConn, err := net.Dial(dialProto, dialAddress)
		if err != nil {
			log.Printf("Error connections to %s:%s", dialProto, dialAddress)
			time.Sleep(retryInterval * time.Second)
			goto AttemptToConnect
		}

		defer syslogConn.Close()

		for line := range sendChan {
			_, err := syslogConn.Write([]byte(line))
			if err != nil {
				syslogConn.Close()
				time.Sleep(retryInterval * time.Second)
				goto AttemptToConnect
			}
		}
	}()

	l, err := net.Listen(listenProto, listenAddress)
	if err != nil {
		log.Printf("net.Listen: %s", err)
		os.Exit(1)
	}
	defer l.Close()

	for {
		conn, err := l.Accept()
		if err != nil {
			log.Printf("l.Accept: %s", err)
			os.Exit(1)
		}
		defer conn.Close()

		go func() {
			reader := bufio.NewReader(conn)
			for {
				line, err := reader.ReadString('\n')
				if err != nil {
					break
				}
				lineParts := strings.Split(line, ceeToken)
				if len(lineParts) != expectedLineParts {
					continue
				}

				var content map[string]interface{}

				err = json.Unmarshal([]byte(lineParts[1]), &content)
				if err != nil {
					continue
				}

				newContent := make(map[string]interface{})
				for k, v := range content {
					k = strings.Replace(k, oldChar, newChar, -1)
					newContent[k] = v
				}

				newJson, err := json.Marshal(newContent)
				if err != nil {
					continue
				}

				newLine := fmt.Sprintf("%s%s%s\n",
					lineParts[0], ceeToken, string(newJson))

				sendChan <- newLine
			}
		}()
	}
}