ctx, cancel := context.WithTimeout(r.Context(), defaultContextTimeout)
		defer cancel()
		if _, err := globalEtcdClient.Get(ctx, "health"); err != nil {
			// etcd unreachable throw an error..
			switch r.Method {
			case http.MethodHead:
				apiErr := toAPIError(r.Context(), err)
				writeResponse(w, apiErr.HTTPStatusCode, nil, mimeNone)
			case http.MethodGet: