Add healthz endpoint

git-svn-id: file:///srv/svn/repo/toyohime/trunk@93 922d331f-388e-da47-97a9-ad700dc0b8b9

cmd/vanityserver/main.go

@@ -3,11 +3,14 @@ Runs a barebones vanity server over HTTP.
 
 Usage
 
-  ./vanityserver [-index] fqdn [repo file]
+  ./vanityserver [-index] [-nohealthz] fqdn [repo file]
 
 The "-index" flag enables an index page at "/" that lists all repos hosted on
 this server.
 
+The "-nohealthz" flag disables the "/healthz" endpoint that returns a 200 OK
+when everything is OK.
+
 If repo file is not given, "./repos" is used. The file has the following format:
 
   pkgroot  vcsScheme://vcsHost/user/repo
@@ -36,7 +39,8 @@ import (
 )
 
 var (
-	showIndex = flag.Bool("index", false, "Show a list of repos at /")
+	showIndex     = flag.Bool("index", false, "Show a list of repos at /")
+	exposeHealthz = flag.Bool("healthz", true, "Expose a healthz endpoint at /healthz")
 )
 
 var host string
@@ -129,6 +133,15 @@ Nothing here.
 	}))
 }
 
+func registerHealthz(mux *http.ServeMux) {
+	mux.Handle("/healthz", http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		_, err := io.WriteString(w, "OK\r\n")
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+		}
+	}))
+}
+
 func main() {
 	flag.Usage = func() {
 		fmt.Fprintf(os.Stderr, "usage: %s fqdn [repos file]", os.Args[0])
@@ -155,6 +168,10 @@ func main() {
 		buildMux(mux, f)
 	}
 
+	if *exposeHealthz {
+		registerHealthz(mux)
+	}
+
 	srv := &http.Server{
 		// This should be sufficient.
 		ReadTimeout:  5 * time.Second,