feat: Introduce activationThreshold/minMetricValue for MongoDB Scaler (…

…#3405)

pkg/scalers/mongo_scaler.go

@@ -57,6 +57,9 @@ type mongoDBMetadata struct {
 	// A threshold that is used as targetAverageValue in HPA
 	// +required
 	queryValue int64
+	// A threshold that is used to check if scaler is active
+	// +optional
+	activationQueryValue int64
 	// The name of the metric to use in the Horizontal Pod Autoscaler. This value will be prefixed with "mongodb-".
 	// +optional
 	metricName string
@@ -134,6 +137,15 @@ func parseMongoDBMetadata(config *ScalerConfig) (*mongoDBMetadata, string, error
 		return nil, "", fmt.Errorf("no queryValue given")
 	}
 
+	meta.activationQueryValue = 0
+	if val, ok := config.TriggerMetadata["activationQueryValue"]; ok {
+		activationQueryValue, err := strconv.ParseInt(val, 10, 64)
+		if err != nil {
+			return nil, "", fmt.Errorf("failed to convert %v to int, because of %v", activationQueryValue, err.Error())
+		}
+		meta.activationQueryValue = activationQueryValue
+	}
+
 	meta.dbName, err = GetFromAuthOrMeta(config, "dbName")
 	if err != nil {
 		return nil, "", err
@@ -196,7 +208,7 @@ func (s *mongoDBScaler) IsActive(ctx context.Context) (bool, error) {
 		mongoDBLog.Error(err, fmt.Sprintf("failed to get query result by mongoDB, because of %v", err))
 		return false, err
 	}
-	return result > 0, nil
+	return result > s.metadata.activationQueryValue, nil
 }
 
 // Close disposes of mongoDB connections

pkg/scalers/mongo_scaler_test.go

@@ -54,6 +54,13 @@ var testMONGODBMetadata = []parseMongoDBMetadataTestData{
 		resolvedEnv: testMongoDBResolvedEnv,
 		raisesError: false,
 	},
+	// wrong activationQueryValue
+	{
+		metadata:    map[string]string{"query": `{"name":"John"}`, "metricName": "hpa", "collection": "demo", "queryValue": "12", "activationQueryValue": "aa", "connectionStringFromEnv": "Mongo_CONN_STR", "dbName": "test"},
+		authParams:  map[string]string{},
+		resolvedEnv: testMongoDBResolvedEnv,
+		raisesError: true,
+	},
 }
 
 var mongoDBMetricIdentifiers = []mongoDBMetricIdentifier{

tests/scalers_go/mongodb/mongodb_test.go

@@ -8,6 +8,7 @@ import (
 	"encoding/base64"
 	"fmt"
 	"testing"
+	"time"
 
 	"github.com/joho/godotenv"
 	"github.com/stretchr/testify/assert"
@@ -144,6 +145,7 @@ spec:
         collection: {{.Collection}}
         query: '{"region":"eu-1","state":"running","plan":"planA"}'
         queryValue: "1"
+        activationQueryValue: "4"
       authenticationRef:
         name: {{.TriggerAuthName}}
 `
@@ -164,6 +166,7 @@ func TestScaler(t *testing.T) {
 		"job count should be 0 after 1 minute")
 
 	// test scaling
+	testActivation(t, kc, mongoPod)
 	testScaleUp(t, kc, mongoPod)
 
 	// cleanup
@@ -221,12 +224,25 @@ func setupMongo(t *testing.T, kc *kubernetes.Clientset) string {
 	return mongoPod
 }
 
+func testActivation(t *testing.T, kc *kubernetes.Clientset, mongoPod string) {
+	t.Log("--- testing activation ---")
+
+	insertCmd := fmt.Sprintf(`db.%s.insert([
+		{"region":"eu-1","state":"running","plan":"planA","goods":"apple"},
+		{"region":"eu-1","state":"running","plan":"planA","goods":"orange"}
+		])`, mongoCollection)
+
+	_, err := ExecuteCommand(fmt.Sprintf("kubectl exec %s -n %s -- mongo --eval '%s'", mongoPod, mongoNamespace, insertCmd))
+	assert.NoErrorf(t, err, "cannot insert mongo records - %s", err)
+	time.Sleep(time.Second * 60)
+	assert.True(t, WaitForJobCount(t, kc, testNamespace, 0, 60, 1),
+		"job count should be 0 after 1 minute")
+}
+
 func testScaleUp(t *testing.T, kc *kubernetes.Clientset, mongoPod string) {
 	t.Log("--- testing scale up ---")
 
 	insertCmd := fmt.Sprintf(`db.%s.insert([
-		{"region":"eu-1","state":"running","plan":"planA","goods":"apple"},
-		{"region":"eu-1","state":"running","plan":"planA","goods":"orange"},
 		{"region":"eu-1","state":"running","plan":"planA","goods":"strawberry"},
 		{"region":"eu-1","state":"running","plan":"planA","goods":"cherry"},
 		{"region":"eu-1","state":"running","plan":"planA","goods":"pineapple"}