Add health endpoint

Adds a health endpoint for the service.

cmd/ot-browser/main.go

@@ -113,6 +113,8 @@ func main() {
 	http.Handle("/", http.StripPrefix("/", fs))
 	http.HandleFunc("/devices", handlerDevices)
 	http.HandleFunc("/devices.json", handlerDevices)
+	http.HandleFunc("/health.json", handlerHealth)
+	http.HandleFunc("/health", handlerHealth)
 	http.HandleFunc("/locations", handlerLocations)
 	http.HandleFunc("/devices/", handlerDeviceQuery)
 	fmt.Println("ot-browser serving: http://" + config.bindAddr)
@@ -143,6 +145,12 @@ func (c *Config) ReadFile(filename string) error {
 	return nil
 }
 
+// handlerHealth - health endpoint - writes a health status message to the client
+func handlerHealth(w http.ResponseWriter, r *http.Request) {
+	w.WriteHeader(http.StatusOK)
+	w.Write([]byte(`{"status":"ok"}`))
+}
+
 func handlerDevices(w http.ResponseWriter, r *http.Request) {
 	devs := make([]string, 0)
 	for dev := range devices {