Update query API to support timeouts (#1014)

* Add timeout parameter for queries

Signed-off-by: Joseph Woodward <joseph.woodward@xeuse.com>

* Update api/prometheus/v1/api.go

Co-authored-by: Kemal Akkoyun <kakkoyun@users.noreply.github.com>
Signed-off-by: Joseph Woodward <joseph.woodward@xeuse.com>

* Update api/prometheus/v1/api.go

Co-authored-by: Kemal Akkoyun <kakkoyun@users.noreply.github.com>
Signed-off-by: Joseph Woodward <joseph.woodward@xeuse.com>

* Pass timeout as stringified time.Duration instead of millisecond value

Signed-off-by: Joseph Woodward <joseph.woodward@xeuse.com>

* Update QueryRange API to support timeouts

Signed-off-by: Joseph Woodward <joseph.woodward@xeuse.com>

* Add timeout to test request params

Signed-off-by: Joseph Woodward <joseph.woodward@xeuse.com>

Co-authored-by: Kemal Akkoyun <kakkoyun@users.noreply.github.com>

api/prometheus/v1/api.go

@@ -238,9 +238,9 @@ type API interface {
 	// LabelValues performs a query for the values of the given label, time range and matchers.
 	LabelValues(ctx context.Context, label string, matches []string, startTime time.Time, endTime time.Time) (model.LabelValues, Warnings, error)
 	// Query performs a query for the given time.
-	Query(ctx context.Context, query string, ts time.Time) (model.Value, Warnings, error)
+	Query(ctx context.Context, query string, ts time.Time, opts ...Option) (model.Value, Warnings, error)
 	// QueryRange performs a query for the given range.
-	QueryRange(ctx context.Context, query string, r Range) (model.Value, Warnings, error)
+	QueryRange(ctx context.Context, query string, r Range, opts ...Option) (model.Value, Warnings, error)
 	// QueryExemplars performs a query for exemplars by the given query and time range.
 	QueryExemplars(ctx context.Context, query string, startTime time.Time, endTime time.Time) ([]ExemplarQueryResult, error)
 	// Buildinfo returns various build information properties about the Prometheus server
@@ -818,10 +818,33 @@ func (h *httpAPI) LabelValues(ctx context.Context, label string, matches []strin
 	return labelValues, w, json.Unmarshal(body, &labelValues)
 }
 
-func (h *httpAPI) Query(ctx context.Context, query string, ts time.Time) (model.Value, Warnings, error) {
+type apiOptions struct {
+	timeout time.Duration
+}
+
+type Option func(c *apiOptions)
+
+func WithTimeout(timeout time.Duration) Option {
+	return func(o *apiOptions) {
+		o.timeout = timeout
+	}
+}
+
+func (h *httpAPI) Query(ctx context.Context, query string, ts time.Time, opts ...Option) (model.Value, Warnings, error) {
+
 	u := h.client.URL(epQuery, nil)
 	q := u.Query()
 
+	opt := &apiOptions{}
+	for _, o := range opts {
+		o(opt)
+	}
+
+	d := opt.timeout
+	if d > 0 {
+		q.Set("timeout", d.String())
+	}
+
 	q.Set("query", query)
 	if !ts.IsZero() {
 		q.Set("time", formatTime(ts))
@@ -836,7 +859,7 @@ func (h *httpAPI) Query(ctx context.Context, query string, ts time.Time) (model.
 	return model.Value(qres.v), warnings, json.Unmarshal(body, &qres)
 }
 
-func (h *httpAPI) QueryRange(ctx context.Context, query string, r Range) (model.Value, Warnings, error) {
+func (h *httpAPI) QueryRange(ctx context.Context, query string, r Range, opts ...Option) (model.Value, Warnings, error) {
 	u := h.client.URL(epQueryRange, nil)
 	q := u.Query()
 
@@ -845,6 +868,16 @@ func (h *httpAPI) QueryRange(ctx context.Context, query string, r Range) (model.
 	q.Set("end", formatTime(r.End))
 	q.Set("step", strconv.FormatFloat(r.Step.Seconds(), 'f', -1, 64))
 
+	opt := &apiOptions{}
+	for _, o := range opts {
+		o(opt)
+	}
+
+	d := opt.timeout
+	if d > 0 {
+		q.Set("timeout", d.String())
+	}
+
 	_, body, warnings, err := h.client.DoGetFallback(ctx, u, q)
 	if err != nil {
 		return nil, warnings, err

api/prometheus/v1/api_test.go

@@ -170,15 +170,15 @@ func TestAPIs(t *testing.T) {
 		}
 	}
 
-	doQuery := func(q string, ts time.Time) func() (interface{}, Warnings, error) {
+	doQuery := func(q string, ts time.Time, opts ...Option) func() (interface{}, Warnings, error) {
 		return func() (interface{}, Warnings, error) {
-			return promAPI.Query(context.Background(), q, ts)
+			return promAPI.Query(context.Background(), q, ts, opts...)
 		}
 	}
 
-	doQueryRange := func(q string, rng Range) func() (interface{}, Warnings, error) {
+	doQueryRange := func(q string, rng Range, opts ...Option) func() (interface{}, Warnings, error) {
 		return func() (interface{}, Warnings, error) {
-			return promAPI.QueryRange(context.Background(), q, rng)
+			return promAPI.QueryRange(context.Background(), q, rng, opts...)
 		}
 	}
 
@@ -246,7 +246,7 @@ func TestAPIs(t *testing.T) {
 
 	queryTests := []apiTest{
 		{
-			do: doQuery("2", testTime),
+			do: doQuery("2", testTime, WithTimeout(5*time.Second)),
 			inRes: &queryResult{
 				Type: model.ValScalar,
 				Result: &model.Scalar{
@@ -260,6 +260,7 @@ func TestAPIs(t *testing.T) {
 			reqParam: url.Values{
 				"query":   []string{"2"},
 				"time":    []string{testTime.Format(time.RFC3339Nano)},
+				"timeout": []string{(5 * time.Second).String()},
 			},
 			res: &model.Scalar{
 				Value:     2,
@@ -365,7 +366,7 @@ func TestAPIs(t *testing.T) {
 				Start: testTime.Add(-time.Minute),
 				End:   testTime,
 				Step:  time.Minute,
-			}),
+			}, WithTimeout(5*time.Second)),
 			inErr: fmt.Errorf("some error"),
 
 			reqMethod: "POST",
@@ -375,6 +376,7 @@ func TestAPIs(t *testing.T) {
 				"start":   []string{testTime.Add(-time.Minute).Format(time.RFC3339Nano)},
 				"end":     []string{testTime.Format(time.RFC3339Nano)},
 				"step":    []string{time.Minute.String()},
+				"timeout": []string{(5 * time.Second).String()},
 			},
 			err: fmt.Errorf("some error"),
 		},

api/prometheus/v1/example_test.go

@@ -39,7 +39,7 @@ func ExampleAPI_query() {
 	v1api := v1.NewAPI(client)
 	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
 	defer cancel()
-	result, warnings, err := v1api.Query(ctx, "up", time.Now())
+	result, warnings, err := v1api.Query(ctx, "up", time.Now(), v1.WithTimeout(5*time.Second))
 	if err != nil {
 		fmt.Printf("Error querying Prometheus: %v\n", err)
 		os.Exit(1)
@@ -67,7 +67,7 @@ func ExampleAPI_queryRange() {
 		End:   time.Now(),
 		Step:  time.Minute,
 	}
-	result, warnings, err := v1api.QueryRange(ctx, "rate(prometheus_tsdb_head_samples_appended_total[5m])", r)
+	result, warnings, err := v1api.QueryRange(ctx, "rate(prometheus_tsdb_head_samples_appended_total[5m])", r, v1.WithTimeout(5*time.Second))
 	if err != nil {
 		fmt.Printf("Error querying Prometheus: %v\n", err)
 		os.Exit(1)