Implement template support

main.go

@@ -8,23 +8,28 @@ import (
 	"log"
 	"os"
 
+	"github.com/valyala/fasttemplate"
 	"gopkg.in/Graylog2/go-gelf.v2/gelf"
 )
 
 const (
-	VERSION = "0.1.2"
+	VERSION = "0.2.0"
 )
 
 func main() {
 	var (
 		listenAddr  string
 		outputFile  string
+		stemplate   string
 		showVersion bool
 		outWriter   io.Writer
+		template    *fasttemplate.Template
 	)
 
 	flag.StringVar(&listenAddr, "listen", "0.0.0.0:12201", "listen address")
 	flag.StringVar(&outputFile, "output", "", "Output file (stdout if empty)")
+	flag.StringVar(&stemplate, "template", "{{TimeUnix}} {{Host}}: {{Short}}",
+		"Output template")
 	flag.BoolVar(&showVersion, "version", false, "Show version and exit")
 	flag.Parse()
 
@@ -33,6 +38,11 @@ func main() {
 		return
 	}
 
+	template, tplerr := fasttemplate.NewTemplate(stemplate, "{{", "}}")
+	if tplerr != nil {
+		log.Fatalf("Error parsing template\n%s", tplerr)
+	}
+
 	if len(outputFile) > 0 {
 		outFile, err := os.OpenFile(outputFile, os.O_APPEND|os.O_WRONLY|os.O_CREATE, 0755)
 		if err != nil {
@@ -52,12 +62,24 @@ func main() {
 
 	fmt.Printf("Listening on %v\n", gelfReader.Addr())
 
+	msgData := make(map[string]interface{}, 8)
+
 	for {
 		msg, err := gelfReader.ReadMessage()
 		if err != nil {
 			log.Printf("Error reading message\n%s\n", err)
 		} else {
-			fmt.Fprintf(outWriter, "%f %v: %v\n", msg.TimeUnix, msg.Host, msg.Short)
+			msgData["Facility"] = msg.Facility
+			msgData["Full"] = msg.Full
+			msgData["Host"] = msg.Host
+			msgData["Level"] = string(msg.Level)
+			msgData["RawExtra"] = string(msg.RawExtra)
+			msgData["Short"] = msg.Short
+			msgData["TimeUnix"] = fmt.Sprintf("%f", msg.TimeUnix)
+			msgData["Version"] = msg.Version
+
+			template.Execute(outWriter, msgData)
+			outWriter.Write([]byte("\n"))
 		}
 	}
 }