add prometheus format

kedacore · Feb 14, 2024 · a951086 · a951086
1 parent 03656b1
commit a951086
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Showing 3 changed files with 67 additions and 48 deletions.
diff --git a/go.mod b/go.mod
@@ -348,7 +348,7 @@ require (
 	gopkg.in/inf.v0 v0.9.1 // indirect
 	gopkg.in/natefinch/lumberjack.v2 v2.2.1 // indirect
 	gopkg.in/yaml.v2 v2.4.0 // indirect
-	gopkg.in/yaml.v3 v3.0.1 // indirect
+	gopkg.in/yaml.v3 v3.0.1
 	k8s.io/apiextensions-apiserver v0.29.0 // indirect
 	k8s.io/gengo v0.0.0-20230829151522-9cce18d56c01 // indirect
 	k8s.io/kms v0.29.0 // indirect

diff --git a/pkg/scalers/metrics_api_scaler.go b/pkg/scalers/metrics_api_scaler.go
@@ -1,17 +1,20 @@
 package scalers
 
 import (
+	"bufio"
+	"bytes"
 	"context"
 	"encoding/xml"
 	"errors"
 	"fmt"
-	"gopkg.in/yaml.v3"
 	"io"
 	"net/http"
 	neturl "net/url"
 	"strconv"
 	"strings"
 
+	"gopkg.in/yaml.v3"
+
 	"github.com/go-logr/logr"
 	"github.com/tidwall/gjson"
 	v2 "k8s.io/api/autoscaling/v2"
@@ -73,17 +76,15 @@ type APIFormat string
 
 // Enum for APIFormat:
 const (
-	PrometheusFormat  APIFormat = "prometheus"
-	OpenMetricsFormat APIFormat = "openmetrics"
-	JSONFormat        APIFormat = "json"
-	XMLFormat         APIFormat = "xml"
-	YAMLFormat        APIFormat = "yaml"
+	PrometheusFormat APIFormat = "prometheus"
+	JSONFormat       APIFormat = "json"
+	XMLFormat        APIFormat = "xml"
+	YAMLFormat       APIFormat = "yaml"
 )
 
 var (
 	supportedFormats = []APIFormat{
-		//PrometheusFormat,
-		//OpenMetricsFormat,
+		PrometheusFormat,
 		JSONFormat,
 		XMLFormat,
 		YAMLFormat,
@@ -249,10 +250,8 @@ func parseMetricsAPIMetadata(config *scalersconfig.ScalerConfig) (*metricsAPISca
 // GetValueFromResponse uses provided valueLocation to access the numeric value in provided body using the format specified.
 func GetValueFromResponse(body []byte, valueLocation string, format APIFormat) (float64, error) {
 	switch format {
-	//case PrometheusFormat:
-	//	return getValueFromPrometheusResponse(body, valueLocation)
-	//case OpenMetricsFormat:
-	//	return getValueFromOpenMetricsResponse(body, valueLocation)
+	case PrometheusFormat:
+		return getValueFromPrometheusResponse(body, valueLocation)
 	case JSONFormat:
 		return getValueFromJSONResponse(body, valueLocation)
 	case XMLFormat:
@@ -264,6 +263,31 @@ func GetValueFromResponse(body []byte, valueLocation string, format APIFormat) (
 	return 0, fmt.Errorf("format %s not supported", format)
 }
 
+// getValueFromPrometheusResponse uses provided valueLocation to access the numeric value in provided body
+func getValueFromPrometheusResponse(body []byte, valueLocation string) (float64, error) {
+	scanner := bufio.NewScanner(bytes.NewReader(body))
+	for scanner.Scan() {
+		line := scanner.Text()
+		fields := strings.Fields(line)
+		if len(fields) == 0 || strings.HasPrefix(fields[0], "#") {
+			continue
+		}
+		if len(fields) == 2 && strings.HasPrefix(fields[0], valueLocation) {
+			value, err := strconv.ParseFloat(fields[1], 64)
+			if err != nil {
+				return 0, err
+			}
+			return value, nil
+		}
+	}
+
+	if err := scanner.Err(); err != nil {
+		return 0, err
+	}
+
+	return 0, fmt.Errorf("Value %s not found", valueLocation)
+}
+
 // getValueFromJSONResponse uses provided valueLocation to access the numeric value in provided body using GSON
 func getValueFromJSONResponse(body []byte, valueLocation string) (float64, error) {
 	r := gjson.GetBytes(body, valueLocation)

diff --git a/pkg/scalers/metrics_api_scaler_test.go b/pkg/scalers/metrics_api_scaler_test.go
@@ -123,45 +123,40 @@ func TestMetricsAPIGetMetricSpecForScaling(t *testing.T) {
 }
 
 func TestGetValueFromResponse(t *testing.T) {
-	t.Run("JSON", func(t *testing.T) {
-		d := []byte(`{"components":[{"id": "82328e93e", "tasks": 32, "str": "64", "k":"1k","wrong":"NaN"}],"count":2.43}`)
-		v, err := GetValueFromResponse(d, "components.0.tasks", JSONFormat)
-		if err != nil {
-			t.Error("Expected success but got error", err)
-		}
-		if v != 32 {
-			t.Errorf("Expected %d got %f", 32, v)
-		}
 
-		v, err = GetValueFromResponse(d, "count", JSONFormat)
-		if err != nil {
-			t.Error("Expected success but got error", err)
-		}
-		if v != 2.43 {
-			t.Errorf("Expected %d got %f", 2, v)
-		}
+	testCases := []struct {
+		name      string
+		input     []byte
+		key       string
+		format    APIFormat
+		expectVal interface{}
+		expectErr bool
+	}{
+		{name: "integer", input: []byte(`{"components":[{"id": "82328e93e", "tasks": 32, "str": "64", "k":"1k","wrong":"NaN"}],"count":2.43}`), key: "count", format: JSONFormat, expectVal: 2.43},
+		{name: "string", input: []byte(`{"components":[{"id": "82328e93e", "tasks": 32, "str": "64", "k":"1k","wrong":"NaN"}],"count":2.43}`), key: "components.0.str", format: JSONFormat, expectVal: 64},
+		{name: "{}.[].{}", input: []byte(`{"components":[{"id": "82328e93e", "tasks": 32, "str": "64", "k":"1k","wrong":"NaN"}],"count":2.43}`), key: "components.0.tasks", format: JSONFormat, expectVal: 32},
+		{name: "invalid data", input: []byte(`{"components":[{"id": "82328e93e", "tasks": 32, "str": "64", "k":"1k","wrong":"NaN"}],"count":2.43}`), key: "components.0.wrong", format: JSONFormat, expectErr: true},
+		{name: "integer", input: []byte(`components: [{id: "82328e93e", tasks: 32, str: "64", k: "1k", wrong: "NaN"}] count: 2.43`), key: "count", format: YAMLFormat, expectVal: 2.43},
+		{name: "string", input: []byte(`components: [{id: "82328e93e", tasks: 32, str: "64", k: "1k", wrong: "NaN"}] count: 2.43`), key: "components.0.str", format: YAMLFormat, expectVal: 64},
+		{name: "{}.[].{}", input: []byte(`components: [{id: "82328e93e", tasks: 32, str: "64", k: "1k", wrong: "NaN"}] count: 2.43`), key: "components.0.tasks", format: YAMLFormat, expectVal: 32},
+		{name: "invalid data", input: []byte(`components: [{id: "82328e93e", tasks: 32, str: "64", k: "1k", wrong: "NaN"}] count: 2.43`), key: "components.0.wrong", format: YAMLFormat, expectErr: true},
+	}
 
-		v, err = GetValueFromResponse(d, "components.0.str", JSONFormat)
-		if err != nil {
-			t.Error("Expected success but got error", err)
-		}
-		if v != 64 {
-			t.Errorf("Expected %d got %f", 64, v)
-		}
+	for _, tc := range testCases {
+		t.Run(string(tc.format)+": "+tc.name, func(t *testing.T) {
+			v, err := GetValueFromResponse(tc.input, tc.key, tc.format)
 
-		v, err = GetValueFromResponse(d, "components.0.k", JSONFormat)
-		if err != nil {
-			t.Error("Expected success but got error", err)
-		}
-		if v != 1000 {
-			t.Errorf("Expected %d got %f", 1000, v)
-		}
+			if tc.expectErr && err == nil {
+				t.Error("Expected error but got success")
+			} else if !tc.expectErr && err != nil {
+				t.Error("Expected success but got error:", err)
+			}
 
-		_, err = GetValueFromResponse(d, "components.0.wrong", JSONFormat)
-		if err == nil {
-			t.Error("Expected error but got success", err)
-		}
-	})
+			if !tc.expectErr && v != tc.expectVal {
+				t.Errorf("Expected %v, got %v", tc.expectVal, v)
+			}
+		})
+	}
 }
 
 func TestMetricAPIScalerAuthParams(t *testing.T) {