Пример #1
0
// Query handles the /api/query endpoint.
func (api *API) Query(w http.ResponseWriter, r *http.Request) {
	setAccessControlHeaders(w)
	w.Header().Set("Content-Type", "application/json")

	params := httputil.GetQueryParams(r)
	expr := params.Get("expr")

	timestamp, err := parseTimestampOrNow(params.Get("timestamp"), api.Now())
	if err != nil {
		httpJSONError(w, fmt.Errorf("invalid query timestamp %s", err), http.StatusBadRequest)
		return
	}

	query, err := api.QueryEngine.NewInstantQuery(expr, timestamp)
	if err != nil {
		httpJSONError(w, err, http.StatusOK)
		return
	}
	res := query.Exec()
	if res.Err != nil {
		httpJSONError(w, res.Err, http.StatusOK)
		return
	}
	log.Debugf("Instant query: %s\nQuery stats:\n%s\n", expr, query.Stats())

	httputil.RespondJSON(w, res.Value)
}
Пример #2
0
// QueryRange handles the /api/query_range endpoint.
func (api *API) QueryRange(w http.ResponseWriter, r *http.Request) {
	setAccessControlHeaders(w)
	w.Header().Set("Content-Type", "application/json")

	params := httputil.GetQueryParams(r)
	expr := params.Get("expr")

	duration, err := parseDuration(params.Get("range"))
	if err != nil {
		httpJSONError(w, fmt.Errorf("invalid query range: %s", err), http.StatusBadRequest)
		return
	}

	step, err := parseDuration(params.Get("step"))
	if err != nil {
		httpJSONError(w, fmt.Errorf("invalid query resolution: %s", err), http.StatusBadRequest)
		return
	}

	end, err := parseTimestampOrNow(params.Get("end"), api.Now())
	if err != nil {
		httpJSONError(w, fmt.Errorf("invalid query timestamp: %s", err), http.StatusBadRequest)
		return
	}
	// TODO(julius): Remove this special-case handling a while after PromDash and
	// other API consumers have been changed to no longer set "end=0" for setting
	// the current time as the end time. Instead, the "end" parameter should
	// simply be omitted or set to an empty string for that case.
	if end == 0 {
		end = api.Now()
	}

	// For safety, limit the number of returned points per timeseries.
	// This is sufficient for 60s resolution for a week or 1h resolution for a year.
	if duration/step > 11000 {
		err := errors.New("exceeded maximum resolution of 11,000 points per timeseries. Try decreasing the query resolution (?step=XX)")
		httpJSONError(w, err, http.StatusBadRequest)
		return
	}

	// Align the start to step "tick" boundary.
	end = end.Add(-time.Duration(end.UnixNano() % int64(step)))
	start := end.Add(-duration)

	query, err := api.QueryEngine.NewRangeQuery(expr, start, end, step)
	if err != nil {
		httpJSONError(w, err, http.StatusOK)
		return
	}
	matrix, err := query.Exec().Matrix()
	if err != nil {
		httpJSONError(w, err, http.StatusOK)
		return
	}

	log.Debugf("Range query: %s\nQuery stats:\n%s\n", expr, query.Stats())
	httputil.RespondJSON(w, matrix)
}