From 75c57ffd006af78dc8411cdf09ec5977591c4de4 Mon Sep 17 00:00:00 2001
From: Fabian Reinartz <fab.reinartz@gmail.com>
Date: Wed, 11 Nov 2015 16:50:54 +0100
Subject: [PATCH] Add version print and flag

---
 main.go | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/main.go b/main.go
index 0ee5a5cf..6ba0aee2 100644
--- a/main.go
+++ b/main.go
@@ -14,13 +14,17 @@
 package main
 
 import (
+	"bytes"
 	"database/sql"
 	"flag"
+	"fmt"
 	"net/http"
 	"os"
 	"os/signal"
 	"path/filepath"
+	"strings"
 	"syscall"
+	template_text "text/template"
 
 	"github.com/prometheus/common/log"
 	"github.com/prometheus/common/route"
@@ -30,17 +34,24 @@ import (
 	"github.com/prometheus/alertmanager/provider"
 	"github.com/prometheus/alertmanager/template"
 	"github.com/prometheus/alertmanager/types"
+	"github.com/prometheus/alertmanager/version"
 )
 
 var (
 	configFile    = flag.String("config.file", "config.yml", "The configuration file")
 	dataDir       = flag.String("data.dir", "data/", "The data directory")
+	showVersion   = flag.Bool("version", false, "Print version information.")
 	listenAddress = flag.String("web.listen-address", ":9093", "Address to listen on for the web interface and API.")
 )
 
 func main() {
 	flag.Parse()
 
+	printVersion()
+	if *showVersion {
+		os.Exit(0)
+	}
+
 	db, err := sql.Open("ql", filepath.Join(*dataDir, "am.db"))
 	if err != nil {
 		log.Fatal(err)
@@ -158,3 +169,20 @@ func main() {
 
 	log.Infoln("Received SIGTERM, exiting gracefully...")
 }
+
+var versionInfoTmpl = `
+alertmanager, version {{.version}} (branch: {{.branch}}, revision: {{.revision}})
+  build user:       {{.buildUser}}
+  build date:       {{.buildDate}}
+  go version:       {{.goVersion}}
+`
+
+func printVersion() {
+	t := template_text.Must(template_text.New("version").Parse(versionInfoTmpl))
+
+	var buf bytes.Buffer
+	if err := t.ExecuteTemplate(&buf, "version", version.Map); err != nil {
+		panic(err)
+	}
+	fmt.Fprintln(os.Stdout, strings.TrimSpace(buf.String()))
+}