Start a Go-based version

eth-log-alerting.go

+package main
+
+import (
+	"flag"
+	"fmt"
+	"log"
+	"os"
+	"os/signal"
+	"path/filepath"
+	"syscall"
+
+	"github.com/asaskevich/govalidator"
+	"github.com/hpcloud/tail"
+)
+
+var (
+	logPath    string
+	webhookURL string
+	username   string
+	channel    string
+	color      string
+	iconURL    string
+
+	logger    *log.Logger
+	debugDest string
+	debug     bool
+
+	tailer *tail.Tail
+)
+
+func init() {
+	flag.StringVar(&logPath, "log-path", "", "Log to monitor")
+	flag.StringVar(&webhookURL, "webhook", "", "Webhook to forward log entries to")
+	flag.StringVar(&username, "username", "logbot", "Username to post as")
+	flag.StringVar(&channel, "channel", "", "Channel to post log entries to")
+	flag.StringVar(&color, "color", "default", "Color for entry, either named or hex with `#`")
+	flag.StringVar(&iconURL, "icon-url", "", "URL of icon to use for bot")
+	flag.StringVar(&debugDest, "debug-dest", "os.Stdout", "Destination for debug and other messages, omit to log to Stdout")
+	flag.BoolVar(&debug, "debug", false, "Include additional log data for debugging")
+	flag.Parse()
+
+	setUpLogger()
+
+	validatePath(&logPath)
+
+	if !govalidator.IsURL(webhookURL) || len(channel) < 2 {
+		usage()
+	}
+}
+
+func main() {
+	logger.Printf("Monitoring %s", logPath)
+	logger.Printf("Forwarding to channel \"%s\" as user \"%s\" at %s", channel, username, webhookURL)
+	sig := make(chan os.Signal, 1)
+	signal.Notify(sig, syscall.SIGINT, syscall.SIGTERM)
+
+	go tailLog()
+
+	caughtSig := <-sig
+	tailer.Stop()
+	tailer.Cleanup()
+	logger.Printf("Stopping, got signal %s", caughtSig)
+}
+
+func tailLog() {
+	t, err := tail.TailFile(logPath, tail.Config{Follow: true, MustExist: true, ReOpen: true})
+	tailer = t
+
+	if err != nil {
+		logger.Println(err)
+		usage()
+	}
+
+	for line := range t.Lines {
+		sendLine(line)
+	}
+}
+
+func sendLine(line *tail.Line) {
+	logger.Println(line.Text)
+}
+
+func setUpLogger() {
+	logOpts := log.Ldate | log.Ltime | log.LUTC | log.Lshortfile
+
+	if debugDest == "os.Stdout" {
+		logger = log.New(os.Stdout, "DEBUG: ", logOpts)
+	} else {
+		path, err := filepath.Abs(debugDest)
+		if err != nil {
+			logger.Fatal(err)
+		}
+
+		logFile, err := os.OpenFile(path, os.O_WRONLY|os.O_CREATE|os.O_APPEND, 0644)
+		if err != nil {
+			log.Fatal(err)
+		}
+
+		logger = log.New(logFile, "", logOpts)
+	}
+}
+
+func validatePath(path *string) {
+	if len(*path) > 1 {
+		var err error
+		*path, err = filepath.Abs(*path)
+
+		if err != nil {
+			fmt.Printf("Error: %s", err.Error())
+			os.Exit(3)
+		}
+
+		if _, err = os.Stat(*path); os.IsNotExist(err) {
+			usage()
+		}
+	} else {
+		usage()
+	}
+}
+
+func usage() {
+	flag.Usage()
+	os.Exit(3)
+}