Improve metric name creation to be unique using scaler index inside the scaler

CHANGELOG.md

@@ -43,6 +43,7 @@
 - Add support to provide the metric name in Azure Log Analytics Scaler ([#2106](https://github.com/kedacore/keda/pull/2106))
 - Add `pageSize` (using regex) in RabbitMQ Scaler ([#2162](https://github.com/kedacore/keda/pull/2162))
 - Add `unsafeSsl` parameter in InfluxDB scaler ([#2157](https://github.com/kedacore/keda/pull/2157))
+- Improve metric name creation to be unique using scaler index inside the scaler ([#2161](https://github.com/kedacore/keda/pull/2161))
 
 ### Breaking Changes
 

CREATE-NEW-SCALER.md

@@ -44,6 +44,31 @@ The return type of this function is `MetricSpec`, but in KEDA's case we will mos
 - `TargetValue`: is the value of the metric we want to reach at all times at all costs. As long as the current metric doesn't match TargetValue, HPA will increase the number of the pods until it reaches the maximum number of pods allowed to scale to.
 - `TargetAverageValue`: the value of the metric for which we require one pod to handle. e.g. if we are have a scaler based on the length of a message queue, and we specificy 10 for `TargetAverageValue`, we are saying that each pod will handle 10 messages. So if the length of the queue becomes 30, we expect that we have 3 pods in our cluster. (`TargetAverage` and `TargetValue` are mutually exclusive)
 
+All scalers receive a parameter named `scalerIndex` as part of `ScalerConfig`. This value is the index of the current scaler in a ScaledObject. All metric names have to start with `sX-` (where `X` is `scalerIndex`). This convention makes the metric name unique in the ScaledObject and brings the option to have more than 1 "similar metric name" defined in a ScaledObject.
+
+For example:
+- s0-redis-mylist
+- s1-redis-mylist
+
+>**Note:** There is a naming helper function `GenerateMetricNameWithIndex(scalerIndex int, metricName string)`, that receives the current index and the original metric name (without the prefix) and returns the concatenated string using the convention (please use this function).<br>Next lines are an example about how to use it:
+>```golang
+>func (s *artemisScaler) GetMetricSpecForScaling() []v2beta2.MetricSpec {
+>	targetMetricValue := resource.NewQuantity(int64(s.metadata.queueLength), resource.DecimalSI)
+>	externalMetric := &v2beta2.ExternalMetricSource{
+>		Metric: v2beta2.MetricIdentifier{
+>			Name: GenerateMetricNameWithIndex(s.metadata.scalerIndex, kedautil.NormalizeString(fmt.Sprintf("%s-%s-%s", "artemis", s.metadata.brokerName, s.metadata.queueName))),
+>		},
+>		Target: v2beta2.MetricTarget{
+>			Type:         v2beta2.AverageValueMetricType,
+>			AverageValue: targetMetricValue,
+>		},
+>	}
+>	metricSpec := v2beta2.MetricSpec{External: externalMetric, Type: artemisMetricType}
+>	return []v2beta2.MetricSpec{metricSpec}
+>}
+>```
+
+
 ### IsActive
 
 For some reason, the scaler might need to declare itself as in-active, and the way it can do this is through implementing the function `IsActive`.

controllers/keda/scaledobject_controller_test.go

@@ -245,8 +245,8 @@ var _ = Describe("ScaledObjectController", func() {
 				return k8sClient.Get(context.Background(), types.NamespacedName{Name: "keda-hpa-clean-up-test", Namespace: "default"}, hpa)
 			}).ShouldNot(HaveOccurred())
 			Expect(hpa.Spec.Metrics).To(HaveLen(2))
-			Expect(hpa.Spec.Metrics[0].External.Metric.Name).To(Equal("cron-UTC-0xxxx-1xxxx"))
-			Expect(hpa.Spec.Metrics[1].External.Metric.Name).To(Equal("cron-UTC-2xxxx-3xxxx"))
+			Expect(hpa.Spec.Metrics[0].External.Metric.Name).To(Equal("s0-cron-UTC-0xxxx-1xxxx"))
+			Expect(hpa.Spec.Metrics[1].External.Metric.Name).To(Equal("s1-cron-UTC-2xxxx-3xxxx"))
 
 			// Remove the second trigger.
 			Eventually(func() error {
@@ -263,7 +263,7 @@ var _ = Describe("ScaledObjectController", func() {
 				return len(hpa.Spec.Metrics)
 			}).Should(Equal(1))
 			// And it should only be the first one left.
-			Expect(hpa.Spec.Metrics[0].External.Metric.Name).To(Equal("cron-UTC-0xxxx-1xxxx"))
+			Expect(hpa.Spec.Metrics[0].External.Metric.Name).To(Equal("s0-cron-UTC-0xxxx-1xxxx"))
 		})
 
 		It("deploys ScaledObject and creates HPA, when IdleReplicaCount, MinReplicaCount and MaxReplicaCount is defined", func() {

pkg/scalers/artemis_scaler.go

@@ -36,6 +36,7 @@ type artemisMetadata struct {
 	restAPITemplate    string
 	queueLength        int
 	corsHeader         string
+	scalerIndex        int
 }
 
 //revive:enable:var-naming
@@ -153,6 +154,9 @@ func parseArtemisMetadata(config *ScalerConfig) (*artemisMetadata, error) {
 	if meta.password == "" {
 		return nil, fmt.Errorf("password cannot be empty")
 	}
+
+	meta.scalerIndex = config.ScalerIndex
+
 	return &meta, nil
 }
 
@@ -250,7 +254,7 @@ func (s *artemisScaler) GetMetricSpecForScaling() []v2beta2.MetricSpec {
 	targetMetricValue := resource.NewQuantity(int64(s.metadata.queueLength), resource.DecimalSI)
 	externalMetric := &v2beta2.ExternalMetricSource{
 		Metric: v2beta2.MetricIdentifier{
-			Name: kedautil.NormalizeString(fmt.Sprintf("%s-%s-%s", "artemis", s.metadata.brokerName, s.metadata.queueName)),
+			Name: GenerateMetricNameWithIndex(s.metadata.scalerIndex, kedautil.NormalizeString(fmt.Sprintf("%s-%s-%s", "artemis", s.metadata.brokerName, s.metadata.queueName))),
 		},
 		Target: v2beta2.MetricTarget{
 			Type:         v2beta2.AverageValueMetricType,

pkg/scalers/artemis_scaler_test.go

@@ -17,6 +17,7 @@ type parseArtemisMetadataTestData struct {
 
 type artemisMetricIdentifier struct {
 	metadataTestData *parseArtemisMetadataTestData
+	scalerIndex      int
 	name             string
 }
 
@@ -59,7 +60,8 @@ var testArtemisMetadata = []parseArtemisMetadataTestData{
 }
 
 var artemisMetricIdentifiers = []artemisMetricIdentifier{
-	{&testArtemisMetadata[7], "artemis-broker-activemq-queue1"},
+	{&testArtemisMetadata[7], 0, "s0-artemis-broker-activemq-queue1"},
+	{&testArtemisMetadata[7], 1, "s1-artemis-broker-activemq-queue1"},
 }
 
 var testArtemisMetadataWithEmptyAuthParams = []parseArtemisMetadataTestData{
@@ -141,7 +143,7 @@ func TestArtemisParseMetadata(t *testing.T) {
 
 func TestArtemisGetMetricSpecForScaling(t *testing.T) {
 	for _, testData := range artemisMetricIdentifiers {
-		meta, err := parseArtemisMetadata(&ScalerConfig{ResolvedEnv: sampleArtemisResolvedEnv, TriggerMetadata: testData.metadataTestData.metadata, AuthParams: nil})
+		meta, err := parseArtemisMetadata(&ScalerConfig{ResolvedEnv: sampleArtemisResolvedEnv, TriggerMetadata: testData.metadataTestData.metadata, AuthParams: nil, ScalerIndex: testData.scalerIndex})
 		if err != nil {
 			t.Fatal("Could not parse metadata:", err)
 		}

pkg/scalers/aws_cloudwatch_scaler.go

@@ -49,6 +49,8 @@ type awsCloudwatchMetadata struct {
 	awsRegion string
 
 	awsAuthorization awsAuthorizationMetadata
+
+	scalerIndex int
 }
 
 var cloudwatchLog = logf.Log.WithName("aws_cloudwatch_scaler")
@@ -189,6 +191,8 @@ func parseAwsCloudwatchMetadata(config *ScalerConfig) (*awsCloudwatchMetadata, e
 
 	meta.awsAuthorization = auth
 
+	meta.scalerIndex = config.ScalerIndex
+
 	return meta, nil
 }
 
@@ -213,7 +217,7 @@ func (c *awsCloudwatchScaler) GetMetricSpecForScaling() []v2beta2.MetricSpec {
 	targetMetricValue := resource.NewQuantity(int64(c.metadata.targetMetricValue), resource.DecimalSI)
 	externalMetric := &v2beta2.ExternalMetricSource{
 		Metric: v2beta2.MetricIdentifier{
-			Name: kedautil.NormalizeString(fmt.Sprintf("%s-%s-%s-%s", "aws-cloudwatch", c.metadata.namespace, c.metadata.dimensionName[0], c.metadata.dimensionValue[0])),
+			Name: GenerateMetricNameWithIndex(c.metadata.scalerIndex, kedautil.NormalizeString(fmt.Sprintf("%s-%s-%s-%s", "aws-cloudwatch", c.metadata.namespace, c.metadata.dimensionName[0], c.metadata.dimensionValue[0]))),
 		},
 		Target: v2beta2.MetricTarget{
 			Type:         v2beta2.AverageValueMetricType,

pkg/scalers/aws_cloudwatch_test.go

@@ -28,6 +28,7 @@ type parseAWSCloudwatchMetadataTestData struct {
 
 type awsCloudwatchMetricIdentifier struct {
 	metadataTestData *parseAWSCloudwatchMetadataTestData
+	scalerIndex      int
 	name             string
 }
 
@@ -233,7 +234,8 @@ var testAWSCloudwatchMetadata = []parseAWSCloudwatchMetadataTestData{
 }
 
 var awsCloudwatchMetricIdentifiers = []awsCloudwatchMetricIdentifier{
-	{&testAWSCloudwatchMetadata[1], "aws-cloudwatch-AWS-SQS-QueueName-keda"},
+	{&testAWSCloudwatchMetadata[1], 0, "s0-aws-cloudwatch-AWS-SQS-QueueName-keda"},
+	{&testAWSCloudwatchMetadata[1], 3, "s3-aws-cloudwatch-AWS-SQS-QueueName-keda"},
 }
 
 func TestCloudwatchParseMetadata(t *testing.T) {
@@ -250,7 +252,7 @@ func TestCloudwatchParseMetadata(t *testing.T) {
 
 func TestAWSCloudwatchGetMetricSpecForScaling(t *testing.T) {
 	for _, testData := range awsCloudwatchMetricIdentifiers {
-		meta, err := parseAwsCloudwatchMetadata(&ScalerConfig{TriggerMetadata: testData.metadataTestData.metadata, ResolvedEnv: testAWSCloudwatchResolvedEnv, AuthParams: testData.metadataTestData.authParams})
+		meta, err := parseAwsCloudwatchMetadata(&ScalerConfig{TriggerMetadata: testData.metadataTestData.metadata, ResolvedEnv: testAWSCloudwatchResolvedEnv, AuthParams: testData.metadataTestData.authParams, ScalerIndex: testData.scalerIndex})
 		if err != nil {
 			t.Fatal("Could not parse metadata:", err)
 		}

pkg/scalers/aws_kinesis_stream_scaler.go

@@ -34,6 +34,7 @@ type awsKinesisStreamMetadata struct {
 	streamName       string
 	awsRegion        string
 	awsAuthorization awsAuthorizationMetadata
+	scalerIndex      int
 }
 
 var kinesisStreamLog = logf.Log.WithName("aws_kinesis_stream_scaler")
@@ -83,6 +84,8 @@ func parseAwsKinesisStreamMetadata(config *ScalerConfig) (*awsKinesisStreamMetad
 
 	meta.awsAuthorization = auth
 
+	meta.scalerIndex = config.ScalerIndex
+
 	return &meta, nil
 }
 
@@ -105,7 +108,7 @@ func (s *awsKinesisStreamScaler) GetMetricSpecForScaling() []v2beta2.MetricSpec
 	targetShardCountQty := resource.NewQuantity(int64(s.metadata.targetShardCount), resource.DecimalSI)
 	externalMetric := &v2beta2.ExternalMetricSource{
 		Metric: v2beta2.MetricIdentifier{
-			Name: kedautil.NormalizeString(fmt.Sprintf("%s-%s", "AWS-Kinesis-Stream", s.metadata.streamName)),
+			Name: GenerateMetricNameWithIndex(s.metadata.scalerIndex, kedautil.NormalizeString(fmt.Sprintf("%s-%s", "AWS-Kinesis-Stream", s.metadata.streamName))),
 		},
 		Target: v2beta2.MetricTarget{
 			Type:         v2beta2.AverageValueMetricType,

pkg/scalers/aws_kinesis_stream_test.go

@@ -19,15 +19,17 @@ var testAWSKinesisAuthentication = map[string]string{
 }
 
 type parseAWSKinesisMetadataTestData struct {
-	metadata   map[string]string
-	expected   *awsKinesisStreamMetadata
-	authParams map[string]string
-	isError    bool
-	comment    string
+	metadata    map[string]string
+	expected    *awsKinesisStreamMetadata
+	authParams  map[string]string
+	isError     bool
+	comment     string
+	scalerIndex int
 }
 
 type awsKinesisMetricIdentifier struct {
 	metadataTestData *parseAWSKinesisMetadataTestData
+	scalerIndex      int
 	name             string
 }
 
@@ -53,27 +55,34 @@ var testAWSKinesisMetadata = []parseAWSKinesisMetadataTestData{
 				awsSecretAccessKey: testAWSKinesisSecretAccessKey,
 				podIdentityOwner:   true,
 			},
+			scalerIndex: 0,
 		},
-		isError: false,
-		comment: "properly formed stream name and region"},
+		isError:     false,
+		comment:     "properly formed stream name and region",
+		scalerIndex: 0,
+	},
 	{
 		metadata: map[string]string{
 			"streamName": "",
 			"shardCount": "2",
 			"awsRegion":  testAWSRegion},
-		authParams: testAWSKinesisAuthentication,
-		expected:   &awsKinesisStreamMetadata{},
-		isError:    true,
-		comment:    "missing stream name"},
+		authParams:  testAWSKinesisAuthentication,
+		expected:    &awsKinesisStreamMetadata{},
+		isError:     true,
+		comment:     "missing stream name",
+		scalerIndex: 1,
+	},
 	{
 		metadata: map[string]string{
 			"streamName": testAWSKinesisStreamName,
 			"shardCount": "2",
 			"awsRegion":  ""},
-		authParams: testAWSKinesisAuthentication,
-		expected:   &awsKinesisStreamMetadata{},
-		isError:    true,
-		comment:    "properly formed stream name, empty region"},
+		authParams:  testAWSKinesisAuthentication,
+		expected:    &awsKinesisStreamMetadata{},
+		isError:     true,
+		comment:     "properly formed stream name, empty region",
+		scalerIndex: 2,
+	},
 	{
 		metadata: map[string]string{
 			"streamName": testAWSKinesisStreamName,
@@ -89,9 +98,12 @@ var testAWSKinesisMetadata = []parseAWSKinesisMetadataTestData{
 				awsSecretAccessKey: testAWSKinesisSecretAccessKey,
 				podIdentityOwner:   true,
 			},
+			scalerIndex: 3,
 		},
-		isError: false,
-		comment: "properly formed stream name and region, empty shard count"},
+		isError:     false,
+		comment:     "properly formed stream name and region, empty shard count",
+		scalerIndex: 3,
+	},
 	{
 		metadata: map[string]string{
 			"streamName": testAWSKinesisStreamName,
@@ -107,10 +119,12 @@ var testAWSKinesisMetadata = []parseAWSKinesisMetadataTestData{
 				awsSecretAccessKey: testAWSKinesisSecretAccessKey,
 				podIdentityOwner:   true,
 			},
+			scalerIndex: 4,
 		},
-		isError: false,
-		comment: "properly formed stream name and region, wrong shard count"},
-
+		isError:     false,
+		comment:     "properly formed stream name and region, wrong shard count",
+		scalerIndex: 4,
+	},
 	{
 		metadata: map[string]string{
 			"streamName": testAWSKinesisStreamName,
@@ -120,9 +134,11 @@ var testAWSKinesisMetadata = []parseAWSKinesisMetadataTestData{
 			"awsAccessKeyID":     "",
 			"awsSecretAccessKey": testAWSKinesisSecretAccessKey,
 		},
-		expected: &awsKinesisStreamMetadata{},
-		isError:  true,
-		comment:  "with AWS Credentials from TriggerAuthentication, missing Access Key Id"},
+		expected:    &awsKinesisStreamMetadata{},
+		isError:     true,
+		comment:     "with AWS Credentials from TriggerAuthentication, missing Access Key Id",
+		scalerIndex: 5,
+	},
 	{metadata: map[string]string{
 		"streamName": testAWSKinesisStreamName,
 		"shardCount": "2",
@@ -131,9 +147,11 @@ var testAWSKinesisMetadata = []parseAWSKinesisMetadataTestData{
 			"awsAccessKeyID":     testAWSKinesisAccessKeyID,
 			"awsSecretAccessKey": "",
 		},
-		expected: &awsKinesisStreamMetadata{},
-		isError:  true,
-		comment:  "with AWS Credentials from TriggerAuthentication, missing Secret Access Key"},
+		expected:    &awsKinesisStreamMetadata{},
+		isError:     true,
+		comment:     "with AWS Credentials from TriggerAuthentication, missing Secret Access Key",
+		scalerIndex: 6,
+	},
 	{metadata: map[string]string{
 		"streamName": testAWSKinesisStreamName,
 		"shardCount": "2",
@@ -149,9 +167,12 @@ var testAWSKinesisMetadata = []parseAWSKinesisMetadataTestData{
 				awsRoleArn:       testAWSKinesisRoleArn,
 				podIdentityOwner: true,
 			},
+			scalerIndex: 7,
 		},
-		isError: false,
-		comment: "with AWS Role from TriggerAuthentication"},
+		isError:     false,
+		comment:     "with AWS Role from TriggerAuthentication",
+		scalerIndex: 7,
+	},
 	{metadata: map[string]string{
 		"streamName":    testAWSKinesisStreamName,
 		"shardCount":    "2",
@@ -165,18 +186,22 @@ var testAWSKinesisMetadata = []parseAWSKinesisMetadataTestData{
 			awsAuthorization: awsAuthorizationMetadata{
 				podIdentityOwner: false,
 			},
+			scalerIndex: 8,
 		},
-		isError: false,
-		comment: "with AWS Role assigned on KEDA operator itself"},
+		isError:     false,
+		comment:     "with AWS Role assigned on KEDA operator itself",
+		scalerIndex: 8,
+	},
 }
 
 var awsKinesisMetricIdentifiers = []awsKinesisMetricIdentifier{
-	{&testAWSKinesisMetadata[1], "AWS-Kinesis-Stream-test"},
+	{&testAWSKinesisMetadata[1], 0, "s0-AWS-Kinesis-Stream-test"},
+	{&testAWSKinesisMetadata[1], 1, "s1-AWS-Kinesis-Stream-test"},
 }
 
 func TestKinesisParseMetadata(t *testing.T) {
 	for _, testData := range testAWSKinesisMetadata {
-		result, err := parseAwsKinesisStreamMetadata(&ScalerConfig{TriggerMetadata: testData.metadata, ResolvedEnv: testAWSKinesisAuthentication, AuthParams: testData.authParams})
+		result, err := parseAwsKinesisStreamMetadata(&ScalerConfig{TriggerMetadata: testData.metadata, ResolvedEnv: testAWSKinesisAuthentication, AuthParams: testData.authParams, ScalerIndex: testData.scalerIndex})
 		if err != nil && !testData.isError {
 			t.Errorf("Expected success because %s got error, %s", testData.comment, err)
 		}
@@ -192,7 +217,7 @@ func TestKinesisParseMetadata(t *testing.T) {
 
 func TestAWSKinesisGetMetricSpecForScaling(t *testing.T) {
 	for _, testData := range awsKinesisMetricIdentifiers {
-		meta, err := parseAwsKinesisStreamMetadata(&ScalerConfig{TriggerMetadata: testData.metadataTestData.metadata, ResolvedEnv: testAWSKinesisAuthentication, AuthParams: testData.metadataTestData.authParams})
+		meta, err := parseAwsKinesisStreamMetadata(&ScalerConfig{TriggerMetadata: testData.metadataTestData.metadata, ResolvedEnv: testAWSKinesisAuthentication, AuthParams: testData.metadataTestData.authParams, ScalerIndex: testData.scalerIndex})
 		if err != nil {
 			t.Fatal("Could not parse metadata:", err)
 		}

pkg/scalers/aws_sqs_queue_scaler.go

@@ -45,6 +45,7 @@ type awsSqsQueueMetadata struct {
 	queueName         string
 	awsRegion         string
 	awsAuthorization  awsAuthorizationMetadata
+	scalerIndex       int
 }
 
 // NewAwsSqsQueueScaler creates a new awsSqsQueueScaler
@@ -105,6 +106,8 @@ func parseAwsSqsQueueMetadata(config *ScalerConfig) (*awsSqsQueueMetadata, error
 
 	meta.awsAuthorization = auth
 
+	meta.scalerIndex = config.ScalerIndex
+
 	return &meta, nil
 }
 
@@ -127,7 +130,7 @@ func (s *awsSqsQueueScaler) GetMetricSpecForScaling() []v2beta2.MetricSpec {
 	targetQueueLengthQty := resource.NewQuantity(int64(s.metadata.targetQueueLength), resource.DecimalSI)
 	externalMetric := &v2beta2.ExternalMetricSource{
 		Metric: v2beta2.MetricIdentifier{
-			Name: kedautil.NormalizeString(fmt.Sprintf("%s-%s", "AWS-SQS-Queue", s.metadata.queueName)),
+			Name: GenerateMetricNameWithIndex(s.metadata.scalerIndex, kedautil.NormalizeString(fmt.Sprintf("%s-%s", "AWS-SQS-Queue", s.metadata.queueName))),
 		},
 		Target: v2beta2.MetricTarget{
 			Type:         v2beta2.AverageValueMetricType,