feat: support indexName in dynamodb scaler

CHANGELOG.md

@@ -53,6 +53,7 @@ To learn more about active deprecations, we recommend checking [GitHub Discussio
 ### Improvements
 
 - **General**: Metrics Adapter: remove deprecated Prometheus Metrics and non-gRPC code ([#3930](https://github.com/kedacore/keda/issues/3930))
+- **AWS DynamoDB:** Add support for `indexName` ([#4680](https://github.com/kedacore/keda/issues/4680))
 - **Azure Data Explorer Scaler**: Use azidentity SDK ([#4489](https://github.com/kedacore/keda/issues/4489))
 - **External Scaler**: Add tls options in TriggerAuth metadata. ([#3565](https://github.com/kedacore/keda/issues/3565))
 - **GCP PubSub Scaler**: Make it more flexible for metrics ([#4243](https://github.com/kedacore/keda/issues/4243))

pkg/scalers/aws_dynamodb_scaler.go

@@ -32,6 +32,7 @@ type awsDynamoDBMetadata struct {
 	keyConditionExpression    string
 	expressionAttributeNames  map[string]*string
 	expressionAttributeValues map[string]*dynamodb.AttributeValue
+	indexName                 string
 	targetValue               int64
 	activationTargetValue     int64
 	awsAuthorization          awsAuthorizationMetadata
@@ -106,6 +107,10 @@ func parseAwsDynamoDBMetadata(config *ScalerConfig) (*awsDynamoDBMetadata, error
 		meta.awsEndpoint = val
 	}
 
+	if val, ok := config.TriggerMetadata["indexName"]; ok {
+		meta.indexName = val
+	}
+
 	if val, ok := config.TriggerMetadata["keyConditionExpression"]; ok && val != "" {
 		meta.keyConditionExpression = val
 	} else {
@@ -218,6 +223,10 @@ func (s *awsDynamoDBScaler) GetQueryMetrics() (float64, error) {
 		ExpressionAttributeValues: s.metadata.expressionAttributeValues,
 	}
 
+	if s.metadata.indexName != "" {
+		dimensions.IndexName = aws.String(s.metadata.indexName)
+	}
+
 	res, err := s.dbClient.Query(&dimensions)
 	if err != nil {
 		s.logger.Error(err, "Failed to get output")

pkg/scalers/aws_dynamodb_scaler_test.go

@@ -18,6 +18,7 @@ const (
 	testAWSDynamoSecretAccessKey = "none"
 	testAWSDynamoErrorTable      = "Error"
 	testAWSDynamoNoValueTable    = "NoValue"
+	testAWSDynamoIndexTable      = "Index"
 )
 
 var testAWSDynamoAuthentication = map[string]string{
@@ -226,6 +227,66 @@ var dynamoTestCases = []parseDynamoDBMetadataTestData{
 			},
 		},
 	},
+	{
+		name: "properly formed dynamo name and region with activationTargetValue",
+		metadata: map[string]string{
+			"tableName":                 "test",
+			"awsRegion":                 "eu-west-1",
+			"keyConditionExpression":    "#yr = :yyyy",
+			"expressionAttributeNames":  "{ \"#yr\" : \"year\" }",
+			"expressionAttributeValues": "{\":yyyy\": {\"N\": \"1994\"}}",
+			"activationTargetValue":     "1",
+			"targetValue":               "3",
+		},
+		authParams:    testAWSDynamoAuthentication,
+		expectedError: nil,
+		expectedMetadata: &awsDynamoDBMetadata{
+			tableName:                 "test",
+			awsRegion:                 "eu-west-1",
+			keyConditionExpression:    "#yr = :yyyy",
+			expressionAttributeNames:  map[string]*string{"#yr": &year},
+			expressionAttributeValues: map[string]*dynamodb.AttributeValue{":yyyy": &yearAttr},
+			activationTargetValue:     1,
+			targetValue:               3,
+			scalerIndex:               1,
+			metricName:                "s1-aws-dynamodb-test",
+			awsAuthorization: awsAuthorizationMetadata{
+				awsAccessKeyID:     "none",
+				awsSecretAccessKey: "none",
+				podIdentityOwner:   true,
+			},
+		},
+	},
+	{
+		name: "properly formed dynamo name and region with index name",
+		metadata: map[string]string{
+			"tableName":                 "test",
+			"awsRegion":                 "eu-west-1",
+			"indexName":                 "test-index",
+			"keyConditionExpression":    "#yr = :yyyy",
+			"expressionAttributeNames":  "{ \"#yr\" : \"year\" }",
+			"expressionAttributeValues": "{\":yyyy\": {\"N\": \"1994\"}}",
+			"targetValue":               "3",
+		},
+		authParams:    testAWSDynamoAuthentication,
+		expectedError: nil,
+		expectedMetadata: &awsDynamoDBMetadata{
+			tableName:                 "test",
+			awsRegion:                 "eu-west-1",
+			indexName:                 "test-index",
+			keyConditionExpression:    "#yr = :yyyy",
+			expressionAttributeNames:  map[string]*string{"#yr": &year},
+			expressionAttributeValues: map[string]*dynamodb.AttributeValue{":yyyy": &yearAttr},
+			targetValue:               3,
+			scalerIndex:               1,
+			metricName:                "s1-aws-dynamodb-test",
+			awsAuthorization: awsAuthorizationMetadata{
+				awsAccessKeyID:     "none",
+				awsSecretAccessKey: "none",
+				podIdentityOwner:   true,
+			},
+		},
+	},
 }
 
 func TestParseDynamoMetadata(t *testing.T) {
@@ -253,6 +314,7 @@ type mockDynamoDB struct {
 }
 
 var result int64 = 4
+var indexResult int64 = 2
 var empty int64
 
 func (c *mockDynamoDB) Query(input *dynamodb.QueryInput) (*dynamodb.QueryOutput, error) {
@@ -265,6 +327,12 @@ func (c *mockDynamoDB) Query(input *dynamodb.QueryInput) (*dynamodb.QueryOutput,
 		}, nil
 	}
 
+	if input.IndexName != nil {
+		return &dynamodb.QueryOutput{
+			Count: &indexResult,
+		}, nil
+	}
+
 	return &dynamodb.QueryOutput{
 		Count: &result,
 	}, nil
@@ -299,6 +367,16 @@ var awsDynamoDBGetMetricTestData = []awsDynamoDBMetadata{
 		expressionAttributeValues: map[string]*dynamodb.AttributeValue{":yyyy": &yearAttr},
 		targetValue:               3,
 	},
+	{
+		tableName:                 testAWSDynamoIndexTable,
+		awsRegion:                 "eu-west-1",
+		indexName:                 "test-index",
+		keyConditionExpression:    "#yr = :yyyy",
+		expressionAttributeNames:  map[string]*string{"#yr": &year},
+		expressionAttributeValues: map[string]*dynamodb.AttributeValue{":yyyy": &yearAttr},
+		activationTargetValue:     3,
+		targetValue:               3,
+	},
 }
 
 func TestDynamoGetMetrics(t *testing.T) {
@@ -309,9 +387,11 @@ func TestDynamoGetMetrics(t *testing.T) {
 			value, _, err := scaler.GetMetricsAndActivity(context.Background(), "aws-dynamodb")
 			switch meta.tableName {
 			case testAWSDynamoErrorTable:
-				assert.Error(t, err, "expect error because of dynamodb api error")
+				assert.EqualError(t, err, "error", "expect error because of dynamodb api error")
 			case testAWSDynamoNoValueTable:
 				assert.NoError(t, err, "dont expect error when returning empty result from dynamodb")
+			case testAWSDynamoIndexTable:
+				assert.EqualValues(t, int64(2), value[0].Value.Value())
 			default:
 				assert.EqualValues(t, int64(4), value[0].Value.Value())
 			}
@@ -327,9 +407,11 @@ func TestDynamoGetQueryMetrics(t *testing.T) {
 			value, err := scaler.GetQueryMetrics()
 			switch meta.tableName {
 			case testAWSDynamoErrorTable:
-				assert.Error(t, err, "expect error because of dynamodb api error")
+				assert.EqualError(t, err, "error", "expect error because of dynamodb api error")
 			case testAWSDynamoNoValueTable:
-				assert.NoError(t, err, "dont expect error when returning empty metric list from cloudwatch")
+				assert.NoError(t, err, "dont expect error when returning empty result from dynamodb")
+			case testAWSDynamoIndexTable:
+				assert.EqualValues(t, int64(2), value)
 			default:
 				assert.EqualValues(t, int64(4), value)
 			}
@@ -345,9 +427,11 @@ func TestDynamoIsActive(t *testing.T) {
 			_, value, err := scaler.GetMetricsAndActivity(context.Background(), "aws-dynamodb")
 			switch meta.tableName {
 			case testAWSDynamoErrorTable:
-				assert.Error(t, err, "expect error because of cloudwatch api error")
+				assert.EqualError(t, err, "error", "expect error because of dynamodb api error")
 			case testAWSDynamoNoValueTable:
 				assert.NoError(t, err, "dont expect error when returning empty result from dynamodb")
+			case testAWSDynamoIndexTable:
+				assert.EqualValues(t, false, value)
 			default:
 				assert.EqualValues(t, true, value)
 			}