[v2] BugFix and Updates for Artemis ActiveMQ scaler (#986)

* BugFix: Username and Password is empty

This fix allows to use a scaler definition without kubernetes secret, passing username and password in scaler metadata according to documentation for scaler

Signed-off-by: Sergiy Poplavskyi <spopla@microsoft.com>

* BugFix: Invalid argument when logging

This fix address an "invalid argument" exception, that throwing any time, when this line executed.

Signed-off-by: Sergiy Poplavskyi <spopla@microsoft.com>

* Feature: Introduce optional metadata patameter "restApiTemplate" to be able to finetune ActiveMQ endpoint

In different versions (or configurations) ActiveMQ REST andpoint can be different, than hardcoded in this scaler. To be able to finetune it, I have introduced an optional parameter to change this template.

Signed-off-by: Sergiy Poplavskyi <spopla@microsoft.com>

* [v2] Added "artemis-queue" scaler to list of scalers for v2

For some reason, ActiveMQ scaler wasn't added to v2. This commit will fix it.

Signed-off-by: Sergiy Poplavskyi <spopla@microsoft.com>

pkg/scalers/artemis_scaler.go

@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"net/http"
 	"strconv"
+	"strings"
 	"time"
 
 	v2beta2 "k8s.io/api/autoscaling/v2beta2"
@@ -28,6 +29,7 @@ type artemisMetadata struct {
 	brokerAddress      string
 	username           string
 	password           string
+	restApiTemplate    string
 	queueLength        int
 }
 
@@ -41,6 +43,7 @@ type artemisMonitoring struct {
 const (
 	artemisMetricType         = "External"
 	defaultArtemisQueueLength = 10
+	defaultRestApiTemplate    = "http://<<managementEndpoint>>/console/jolokia/read/org.apache.activemq.artemis:broker=\"<<brokerName>>\",component=addresses,address=\"<<brokerAddress>>\",subcomponent=queues,routing-type=\"anycast\",queue=\"<<queueName>>\"/MessageCount"
 )
 
 var artemisLog = logf.Log.WithName("artemis_queue_scaler")
@@ -63,6 +66,12 @@ func parseArtemisMetadata(resolvedEnv, metadata, authParams map[string]string) (
 
 	meta.queueLength = defaultArtemisQueueLength
 
+	if val, ok := metadata["restApiTemplate"]; ok && val != "" {
+		meta.restApiTemplate = metadata["restApiTemplate"]
+	} else {
+		meta.restApiTemplate = defaultRestApiTemplate
+	}
+
 	if metadata["managementEndpoint"] == "" {
 		return nil, errors.New("no management endpoint given")
 	}
@@ -92,27 +101,31 @@ func parseArtemisMetadata(resolvedEnv, metadata, authParams map[string]string) (
 		meta.queueLength = queueLength
 	}
 
-	if val, ok := authParams["username"]; ok {
+	if val, ok := authParams["username"]; ok && val != "" {
 		meta.username = val
-	} else if val, ok := metadata["username"]; ok {
+	} else if val, ok := metadata["username"]; ok && val != "" {
 		username := val
 
-		if val, ok := resolvedEnv[username]; ok {
+		if val, ok := resolvedEnv[username]; ok && val != "" {
 			meta.username = val
+		} else {
+			meta.username = username
 		}
 	}
 
 	if meta.username == "" {
 		return nil, fmt.Errorf("username cannot be empty")
 	}
 
-	if val, ok := authParams["password"]; ok {
+	if val, ok := authParams["password"]; ok && val != "" {
 		meta.password = val
-	} else if val, ok := metadata["password"]; ok {
+	} else if val, ok := metadata["password"]; ok && val != "" {
 		password := val
 
-		if val, ok := resolvedEnv[password]; ok {
+		if val, ok := resolvedEnv[password]; ok && val != "" {
 			meta.password = val
+		} else {
+			meta.password = password
 		}
 	}
 
@@ -133,13 +146,15 @@ func (s *artemisScaler) IsActive(ctx context.Context) (bool, error) {
 	return messages > 0, nil
 }
 
-func (s *artemisScaler) getArtemisManagementEndpoint() string {
-	return "http://" + s.metadata.managementEndpoint
-}
-
 func (s *artemisScaler) getMonitoringEndpoint() string {
-	monitoringEndpoint := fmt.Sprintf("%s/console/jolokia/read/org.apache.activemq.artemis:broker=\"%s\",component=addresses,address=\"%s\",subcomponent=queues,routing-type=\"anycast\",queue=\"%s\"/MessageCount",
-		s.getArtemisManagementEndpoint(), s.metadata.brokerName, s.metadata.brokerAddress, s.metadata.queueName)
+
+	replacer := strings.NewReplacer("<<managementEndpoint>>", s.metadata.managementEndpoint,
+		"<<queueName>>", s.metadata.queueName,
+		"<<brokerName>>", s.metadata.brokerName,
+		"<<brokerAddress>>", s.metadata.brokerAddress)
+
+	monitoringEndpoint := replacer.Replace(s.metadata.restApiTemplate)
+
 	return monitoringEndpoint
 }
 
@@ -174,7 +189,7 @@ func (s *artemisScaler) getQueueMessageCount() (int, error) {
 		return -1, fmt.Errorf("Artemis management endpoint response error code : %d", resp.StatusCode)
 	}
 
-	artemisLog.V(1).Info("Artemis scaler: Providing metrics based on current queue length ", messageCount, "queue length limit", s.metadata.queueLength)
+	artemisLog.V(1).Info(fmt.Sprintf("Artemis scaler: Providing metrics based on current queue length %d queue length limit %d", messageCount, s.metadata.queueLength))
 
 	return messageCount, nil
 }

pkg/scaling/scale_handler.go

@@ -364,6 +364,8 @@ func (h *scaleHandler) getPods(scalableObject interface{}) (*corev1.PodTemplateS
 
 func buildScaler(name, namespace, triggerType string, resolvedEnv, triggerMetadata, authParams map[string]string, podIdentity string) (scalers.Scaler, error) {
 	switch triggerType {
+	case "artemis-queue":
+		return scalers.NewArtemisQueueScaler(resolvedEnv, triggerMetadata, authParams)
 	case "azure-queue":
 		return scalers.NewAzureQueueScaler(resolvedEnv, triggerMetadata, authParams, podIdentity)
 	case "azure-servicebus":