feat(scaler): support cloudID and apiKey in elasticsearch scaler

Signed-off-by: Rogerio Peixoto <rcbpeixoto@gmail.com>

CHANGELOG.md

@@ -47,6 +47,7 @@ To learn more about active deprecations, we recommend checking [GitHub Discussio
 - **AWS Scalers**: Add setting AWS endpoint url. ([#3337](https://github.com/kedacore/keda/issues/3337))
 - **Azure Service Bus Scaler**: Add support for Shared Access Signature (SAS) tokens for authentication. ([#2920](https://github.com/kedacore/keda/issues/2920))
 - **Azure Service Bus Scaler:** Support regex usage in queueName / subscriptionName parameters. ([#1624](https://github.com/kedacore/keda/issues/1624))
+- **ElasticSearch Scaler**: Support for ElasticSearch Service on Elastic Cloud ([#3785]https://github.com/kedacore/keda/issues/3785)
 - **Selenium Grid Scaler:** Allow setting url trigger parameter from TriggerAuthentication/ClusterTriggerAuthentication ([#3752](https://github.com/kedacore/keda/pull/3752))
 
 ### Improvements

pkg/scalers/elasticsearch_scaler.go

@@ -33,6 +33,8 @@ type elasticsearchMetadata struct {
 	unsafeSsl             bool
 	username              string
 	password              string
+	cloudID               string
+	apiKey                string
 	indexes               []string
 	searchTemplateName    string
 	parameters            []string
@@ -70,25 +72,36 @@ func NewElasticsearchScaler(config *ScalerConfig) (Scaler, error) {
 
 const defaultUnsafeSsl = false
 
-func parseElasticsearchMetadata(config *ScalerConfig) (*elasticsearchMetadata, error) {
-	meta := elasticsearchMetadata{}
+func hasCloudConfig(meta *elasticsearchMetadata) bool {
+	if meta.cloudID != "" {
+		return true
+	}
+	if meta.apiKey != "" {
+		return true
+	}
+	return false
+}
 
-	var err error
-	addresses, err := GetFromAuthOrMeta(config, "addresses")
-	if err != nil {
-		return nil, err
+func hasEndpointsConfig(meta *elasticsearchMetadata) bool {
+	if len(meta.addresses) > 0 {
+		return true
 	}
-	meta.addresses = splitAndTrimBySep(addresses, ",")
+	if meta.username != "" {
+		return true
+	}
+	if meta.password != "" {
+		return true
+	}
+	return false
+}
 
-	if val, ok := config.TriggerMetadata["unsafeSsl"]; ok {
-		meta.unsafeSsl, err = strconv.ParseBool(val)
-		if err != nil {
-			return nil, fmt.Errorf("error parsing unsafeSsl: %s", err)
-		}
-	} else {
-		meta.unsafeSsl = defaultUnsafeSsl
+func extractEndpointsConfig(config *ScalerConfig, meta *elasticsearchMetadata) error {
+	addresses, err := GetFromAuthOrMeta(config, "addresses")
+	if err != nil {
+		return err
 	}
 
+	meta.addresses = splitAndTrimBySep(addresses, ",")
 	if val, ok := config.AuthParams["username"]; ok {
 		meta.username = val
 	} else if val, ok := config.TriggerMetadata["username"]; ok {
@@ -101,6 +114,60 @@ func parseElasticsearchMetadata(config *ScalerConfig) (*elasticsearchMetadata, e
 		meta.password = config.ResolvedEnv[config.TriggerMetadata["passwordFromEnv"]]
 	}
 
+	return nil
+}
+
+func extractCloudConfig(config *ScalerConfig, meta *elasticsearchMetadata) error {
+	cloudID, err := GetFromAuthOrMeta(config, "cloudID")
+	if err != nil {
+		return err
+	}
+	meta.cloudID = cloudID
+
+	apiKey, err := GetFromAuthOrMeta(config, "apiKey")
+	if err != nil {
+		return err
+	}
+	meta.apiKey = apiKey
+	return nil
+}
+
+func parseElasticsearchMetadata(config *ScalerConfig) (*elasticsearchMetadata, error) {
+	meta := elasticsearchMetadata{}
+
+	var err error
+	addresses, err := GetFromAuthOrMeta(config, "addresses")
+	cloudID, errCloudConfig := GetFromAuthOrMeta(config, "cloudID")
+	if err != nil && errCloudConfig != nil {
+		return nil, fmt.Errorf("must provide either endpoint addresses or cloud config")
+	}
+
+	if err == nil && addresses != "" {
+		err = extractEndpointsConfig(config, &meta)
+		if err != nil {
+			return nil, err
+		}
+	}
+	if errCloudConfig == nil && cloudID != "" {
+		err = extractCloudConfig(config, &meta)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	if hasEndpointsConfig(&meta) && hasCloudConfig(&meta) {
+		return nil, fmt.Errorf("can't provide endpoint addresses and cloud config at the same time")
+	}
+
+	if val, ok := config.TriggerMetadata["unsafeSsl"]; ok {
+		meta.unsafeSsl, err = strconv.ParseBool(val)
+		if err != nil {
+			return nil, fmt.Errorf("error parsing unsafeSsl: %s", err)
+		}
+	} else {
+		meta.unsafeSsl = defaultUnsafeSsl
+	}
+
 	index, err := GetFromAuthOrMeta(config, "index")
 	if err != nil {
 		return nil, err
@@ -144,12 +211,23 @@ func parseElasticsearchMetadata(config *ScalerConfig) (*elasticsearchMetadata, e
 
 // newElasticsearchClient creates elasticsearch db connection
 func newElasticsearchClient(meta *elasticsearchMetadata, logger logr.Logger) (*elasticsearch.Client, error) {
-	config := elasticsearch.Config{Addresses: meta.addresses}
-	if meta.username != "" {
-		config.Username = meta.username
-	}
-	if meta.password != "" {
-		config.Password = meta.password
+	var config elasticsearch.Config
+
+	if hasCloudConfig(meta) {
+		config = elasticsearch.Config{
+			CloudID: meta.cloudID,
+			APIKey:  meta.apiKey,
+		}
+	} else {
+		config = elasticsearch.Config{
+			Addresses: meta.addresses,
+		}
+		if meta.username != "" {
+			config.Username = meta.username
+		}
+		if meta.password != "" {
+			config.Password = meta.password
+		}
 	}
 
 	transport := http.DefaultTransport.(*http.Transport)

pkg/scalers/elasticsearch_scaler_test.go

@@ -33,10 +33,22 @@ type elasticsearchMetricIdentifier struct {
 
 var testCases = []parseElasticsearchMetadataTestData{
 	{
-		name:          "no addresses given",
+		name:          "must provide either endpoint addresses or cloud config",
 		metadata:      map[string]string{},
 		authParams:    map[string]string{},
-		expectedError: errors.New("no addresses given"),
+		expectedError: errors.New("must provide either endpoint addresses or cloud config"),
+	},
+	{
+		name:          "no apiKey given",
+		metadata:      map[string]string{"cloudID": "my-cluster:xxxxxxxxxxx"},
+		authParams:    map[string]string{},
+		expectedError: errors.New("no apiKey given"),
+	},
+	{
+		name:          "can't provide endpoint addresses and cloud config at the same time",
+		metadata:      map[string]string{"addresses": "http://localhost:9200", "cloudID": "my-cluster:xxxxxxxxxxx"},
+		authParams:    map[string]string{"username": "admin", "apiKey": "xxxxxxxxx"},
+		expectedError: errors.New("can't provide endpoint addresses and cloud config at the same time"),
 	},
 	{
 		name:          "no index given",
@@ -447,6 +459,10 @@ func TestElasticsearchGetMetricSpecForScaling(t *testing.T) {
 			AuthParams:      testData.metadataTestData.authParams,
 			ScalerIndex:     testData.scalerIndex,
 		})
+		if testData.metadataTestData.expectedError != nil {
+			assert.Equal(t, err, testData.metadataTestData.expectedError)
+			continue
+		}
 		if err != nil {
 			t.Fatal("Could not parse metadata:", err)
 		}