etcdserver/api/etcdhttp/metrics.go
func NewHealthHandler(hfunc func() Health) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		if r.Method != http.MethodGet {
			w.Header().Set("Allow", http.MethodGet)
			http.Error(w, "Method Not Allowed", http.StatusMethodNotAllowed)
			return
		}
		h := hfunc()
		d, _ := json.Marshal(h)
		if h.Health != "true" {
			http.Error(w, string(d), http.StatusServiceUnavailable)
			return
		}
		w.WriteHeader(http.StatusOK)
		w.Write(d)
	}
}
func NewHealthHandler(hfunc func() Health) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		if r.Method != http.MethodGet {
			w.Header().Set("Allow", http.MethodGet)
			http.Error(w, "Method Not Allowed", http.StatusMethodNotAllowed)
			return
		}
		h := hfunc()
		d, _ := json.Marshal(h)
		if h.Health != "true" {
			http.Error(w, string(d), http.StatusServiceUnavailable)
			return
		}
		w.WriteHeader(http.StatusOK)
		w.Write(d)
	}
}
// NewHealthHandler handles '/health' requests.