vmalert: support scalar type in response (#2610)

See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/2607

Signed-off-by: hagen1778 <roman@victoriametrics.com>

app/vmalert/Makefile

@@ -69,7 +69,7 @@ test-vmalert:
 	go test -v -race -cover ./app/vmalert/remotewrite
 
 run-vmalert: vmalert
-	./bin/vmalert -rule=app/vmalert/config/testdata/rules2-good.rules \
+	./bin/vmalert -rule=app/vmalert/config/testdata/rules/rules2-good.rules \
 		-datasource.url=http://localhost:8428 \
 		-notifier.url=http://localhost:9093 \
 		-notifier.url=http://127.0.0.1:9093 \
@@ -78,7 +78,7 @@ run-vmalert: vmalert
 		-external.label=cluster=east-1 \
 		-external.label=replica=a \
 		-evaluationInterval=3s \
-		-rule.configCheckInterval=10s
+		-configCheckInterval=10s
 
 run-vmalert-sd: vmalert
 	./bin/vmalert -rule=app/vmalert/config/testdata/rules2-good.rules \

app/vmalert/config/testdata/rules/rules2-good.rules

@@ -2,8 +2,6 @@ groups:
   - name: TestGroup
     interval: 2s
     concurrency: 2
-    extra_filter_labels: # deprecated param, use `params` instead
-        job: victoriametrics
     params:
       denyPartialResponse: ["true"]
       extra_label: ["env=dev"]
@@ -50,3 +48,11 @@ groups:
             sum(code:requests:rate5m{code="200"})
           /
             sum(code:requests:rate5m)
+      - record: code:requests:slo
+        labels:
+           recording: true
+        expr: 0.95
+      - record: time:current
+        labels:
+           recording: true
+        expr: time()

app/vmalert/datasource/vm_prom_api.go

@@ -31,13 +31,6 @@ type promInstant struct {
 	} `json:"result"`
 }
 
-type promRange struct {
-	Result []struct {
-		Labels map[string]string `json:"metric"`
-		TVs    [][2]interface{}  `json:"values"`
-	} `json:"result"`
-}
-
 func (r promInstant) metrics() ([]Metric, error) {
 	var result []Metric
 	for i, res := range r.Result {
@@ -56,6 +49,13 @@ func (r promInstant) metrics() ([]Metric, error) {
 	return result, nil
 }
 
+type promRange struct {
+	Result []struct {
+		Labels map[string]string `json:"metric"`
+		TVs    [][2]interface{}  `json:"values"`
+	} `json:"result"`
+}
+
 func (r promRange) metrics() ([]Metric, error) {
 	var result []Metric
 	for i, res := range r.Result {
@@ -80,9 +80,22 @@ func (r promRange) metrics() ([]Metric, error) {
 	return result, nil
 }
 
+type promScalar [2]interface{}
+
+func (r promScalar) metrics() ([]Metric, error) {
+	var m Metric
+	f, err := strconv.ParseFloat(r[1].(string), 64)
+	if err != nil {
+		return nil, fmt.Errorf("metric %v, unable to parse float64 from %s: %w", r, r[1], err)
+	}
+	m.Values = append(m.Values, f)
+	m.Timestamps = append(m.Timestamps, int64(r[0].(float64)))
+	return []Metric{m}, nil
+}
+
 const (
-	statusSuccess, statusError = "success", "error"
-	rtVector, rtMatrix         = "vector", "matrix"
+	statusSuccess, statusError  = "success", "error"
+	rtVector, rtMatrix, rScalar = "vector", "matrix", "scalar"
 )
 
 func parsePrometheusResponse(req *http.Request, resp *http.Response) ([]Metric, error) {
@@ -109,7 +122,14 @@ func parsePrometheusResponse(req *http.Request, resp *http.Response) ([]Metric,
 			return nil, err
 		}
 		return pr.metrics()
+	case rScalar:
+		var ps promScalar
+		if err := json.Unmarshal(r.Data.Result, &ps); err != nil {
+			return nil, err
+		}
+		return ps.metrics()
 	default:
+		fmt.Println(string(r.Data.Result))
 		return nil, fmt.Errorf("unknown result type %q", r.Data.ResultType)
 	}
 }

app/vmalert/datasource/vm_test.go

@@ -37,7 +37,7 @@ func TestVMInstantQuery(t *testing.T) {
 	mux.HandleFunc("/render", func(w http.ResponseWriter, request *http.Request) {
 		c++
 		switch c {
-		case 7:
+		case 8:
 			w.Write([]byte(`[{"target":"constantLine(10)","tags":{"name":"constantLine(10)"},"datapoints":[[10,1611758343],[10,1611758373],[10,1611758403]]}]`))
 		}
 	})
@@ -75,6 +75,8 @@ func TestVMInstantQuery(t *testing.T) {
 			w.Write([]byte(`{"status":"success","data":{"resultType":"matrix"}}`))
 		case 6:
 			w.Write([]byte(`{"status":"success","data":{"resultType":"vector","result":[{"metric":{"__name__":"vm_rows"},"value":[1583786142,"13763"]},{"metric":{"__name__":"vm_requests"},"value":[1583786140,"2000"]}]}}`))
+		case 7:
+			w.Write([]byte(`{"status":"success","data":{"resultType":"scalar","result":[1583786142, "1"]}}`))
 		}
 	})
 
@@ -91,25 +93,20 @@ func TestVMInstantQuery(t *testing.T) {
 	pq := s.BuildWithParams(QuerierParams{DataSourceType: &p, EvaluationInterval: 15 * time.Second})
 	ts := time.Now()
 
-	if _, err := pq.Query(ctx, query, ts); err == nil {
-		t.Fatalf("expected connection error got nil")
+	expErr := func(err string) {
+		if _, err := pq.Query(ctx, query, ts); err == nil {
+			t.Fatalf("expected %q got nil", err)
+		}
 	}
-	if _, err := pq.Query(ctx, query, ts); err == nil {
-		t.Fatalf("expected invalid response status error got nil")
-	}
-	if _, err := pq.Query(ctx, query, ts); err == nil {
-		t.Fatalf("expected response body error got nil")
-	}
-	if _, err := pq.Query(ctx, query, ts); err == nil {
-		t.Fatalf("expected error status got nil")
-	}
-	if _, err := pq.Query(ctx, query, ts); err == nil {
-		t.Fatalf("expected unknown status got nil")
-	}
-	if _, err := pq.Query(ctx, query, ts); err == nil {
-		t.Fatalf("expected non-vector resultType error  got nil")
-	}
-	m, err := pq.Query(ctx, query, ts)
+
+	expErr("connection error")              // 0
+	expErr("invalid response status error") // 1
+	expErr("response body error")           // 2
+	expErr("error status")                  // 3
+	expErr("unknown status")                // 4
+	expErr("non-vector resultType error")   // 5
+
+	m, err := pq.Query(ctx, query, ts) // 6 - vector
 	if err != nil {
 		t.Fatalf("unexpected %s", err)
 	}
@@ -132,10 +129,27 @@ func TestVMInstantQuery(t *testing.T) {
 		t.Fatalf("unexpected metric %+v want %+v", m, expected)
 	}
 
+	m, err = pq.Query(ctx, query, ts) // 7 - scalar
+	if err != nil {
+		t.Fatalf("unexpected %s", err)
+	}
+	if len(m) != 1 {
+		t.Fatalf("expected 1 metrics got %d in %+v", len(m), m)
+	}
+	expected = []Metric{
+		{
+			Timestamps: []int64{1583786142},
+			Values:     []float64{1},
+		},
+	}
+	if !reflect.DeepEqual(m, expected) {
+		t.Fatalf("unexpected metric %+v want %+v", m, expected)
+	}
+
 	g := NewGraphiteType()
 	gq := s.BuildWithParams(QuerierParams{DataSourceType: &g})
 
-	m, err = gq.Query(ctx, queryRender, ts)
+	m, err = gq.Query(ctx, queryRender, ts) // 8 - graphite
 	if err != nil {
 		t.Fatalf("unexpected %s", err)
 	}

docs/CHANGELOG.md

@@ -18,6 +18,7 @@ The following tip changes can be tested by building VictoriaMetrics components f
 * FEATURE: [vmalert](https://docs.victoriametrics.com/vmalert.html): support [reusable templates](https://prometheus.io/docs/prometheus/latest/configuration/template_examples/#defining-reusable-templates) for rules annotations. The path to the template files can be specified via `-rule.templates` flag. See more about this feature [here](https://docs.victoriametrics.com/vmalert.html#reusable-templates). Thanks to @AndrewChubatiuk for [the pull request](https://github.com/VictoriaMetrics/VictoriaMetrics/pull/2532).
 * FEATURE: [vmctl](https://docs.victoriametrics.com/vmctl.html): add `influx-prometheus-mode` command-line flag, which allows to restore the original time series written from Prometheus into InfluxDB during data migration from InfluxDB to VictoriaMetrics. See [this feature request](https://github.com/VictoriaMetrics/vmctl/issues/8). Thanks to @mback2k for [the pull request](https://github.com/VictoriaMetrics/VictoriaMetrics/pull/2545).
 
+* BUGFIX: [vmalert](https://docs.victoriametrics.com/vmalert.html): support `scalar` result type in response. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/2607.
 * BUGFIX: [vmalert](https://docs.victoriametrics.com/vmalert.html): support strings in `humanize.*` template function. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/2569.
 * BUGFIX: [vmalert](https://docs.victoriametrics.com/vmalert.html): proxy `/rules` requests to vmalert from Grafana's alerting UI. This removes errors in Grafana's UI for Grafana versions older than 8.5.*. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/2583.
 * BUGFIX: [MetricsQL](https://docs.victoriametrics.com/MetricsQL.html): do not return values from [label_value()](https://docs.victoriametrics.com/MetricsQL.html#label_value) function if the original time series has no values at the selected timestamps.