From 866c2e938c14fe4d39d303eb47cf9c72cd0248d6 Mon Sep 17 00:00:00 2001
From: Mel Cone <melcone@microsoft.com>
Date: Thu, 30 Jan 2020 17:03:32 -0500
Subject: [PATCH] Add support for custom aggregation interval. Clean up code
 and remove unused parts from struct

---
 pkg/scalers/azure_monitor.go        | 59 ++++++++++++++---------------
 pkg/scalers/azure_monitor_scaler.go |  1 -
 2 files changed, 29 insertions(+), 31 deletions(-)

diff --git a/pkg/scalers/azure_monitor.go b/pkg/scalers/azure_monitor.go
index 96760b2799c..fbfd6e146df 100644
--- a/pkg/scalers/azure_monitor.go
+++ b/pkg/scalers/azure_monitor.go
@@ -3,8 +3,9 @@ package scalers
 import (
 	"context"
 	"fmt"
-	"math"
-	"strings"
+    "math"
+    "strconv"
+    "strings"
 	"time"
 
 	"github.com/Azure/azure-sdk-for-go/services/preview/monitor/mgmt/2018-03-01/insights"
@@ -15,7 +16,6 @@ import (
 type azureExternalMetricRequest struct {
 	MetricName                string
 	SubscriptionID            string
-	Type                      string
 	ResourceName              string
 	ResourceProviderNamespace string
 	ResourceType              string
@@ -23,8 +23,6 @@ type azureExternalMetricRequest struct {
 	Timespan                  string
 	Filter                    string
 	ResourceGroup             string
-	Topic                     string
-	Subscription              string
 }
 
 type azureExternalMetricResponse struct {
@@ -48,33 +46,25 @@ func GetAzureMetricValue(ctx context.Context, metricMetadata *azureMonitorMetada
 	metricsClient := newMonitorClient(metricMetadata)
 
 	metricRequest := azureExternalMetricRequest{
-		Timespan:       timeSpan(),
+		MetricName:     metricMetadata.name,
 		SubscriptionID: metricMetadata.subscriptionID,
+		Aggregation:    metricMetadata.aggregationType,
+		Filter:         metricMetadata.filter,
+		ResourceGroup:  metricMetadata.resourceGroupName,
 	}
 
-	metricRequest.MetricName = metricMetadata.name
-	metricRequest.ResourceGroup = metricMetadata.resourceGroupName
 	resourceInfo := strings.Split(metricMetadata.resourceURI, "/")
-
-	if len(resourceInfo) != 3 {
-		return -1, fmt.Errorf("resourceURI is missing resource namespace, resource type, or resource name")
-	}
-
 	metricRequest.ResourceProviderNamespace = resourceInfo[0]
 	metricRequest.ResourceType = resourceInfo[1]
 	metricRequest.ResourceName = resourceInfo[2]
 
-	metricRequest.Aggregation = metricMetadata.aggregationType
+	// if no timespan is provided, defaults to 5 minutes
+	timespan, err := formatTimeSpan(metricMetadata.aggregationInterval)
+	if err != nil {
+		return -1, err
+    }
 
-	filter := metricMetadata.filter
-	if filter != "" {
-		metricRequest.Filter = filter
-	}
-
-	aggregationInterval := metricMetadata.aggregationInterval
-	if aggregationInterval != "" {
-		metricRequest.Timespan = aggregationInterval
-	}
+	metricRequest.Timespan = timespan
 
 	metricResponse, err := metricsClient.getAzureMetric(metricRequest)
 	if err != nil {
@@ -93,10 +83,8 @@ func newMonitorClient(metadata *azureMonitorMetadata) azureExternalMetricClient
 	client := insights.NewMetricsClient(metadata.subscriptionID)
 	config := auth.NewClientCredentialsConfig(metadata.clientID, metadata.clientPassword, metadata.tentantID)
 
-	authorizer, err := config.Authorizer()
-	if err == nil {
-		client.Authorizer = authorizer
-	}
+	authorizer, _ := config.Authorizer()
+	client.Authorizer = authorizer
 
 	return &monitorClient{
 		client: client,
@@ -197,10 +185,21 @@ func (amr azureExternalMetricRequest) metricResourceURI() string {
 		amr.ResourceName)
 }
 
-func timeSpan() string {
+func formatTimeSpan(timeSpan string) (string, error) {
 	// defaults to last five minutes.
-	// TODO support configuration via config
 	endtime := time.Now().UTC().Format(time.RFC3339)
 	starttime := time.Now().Add(-(5 * time.Minute)).UTC().Format(time.RFC3339)
-	return fmt.Sprintf("%s/%s", starttime, endtime)
+	if timeSpan != "" {
+		aggregationInterval := strings.Split(timeSpan, ":")
+		hours, herr := strconv.Atoi(aggregationInterval[0])
+		minutes, merr := strconv.Atoi(aggregationInterval[1])
+		seconds, serr := strconv.Atoi(aggregationInterval[2])
+
+		if herr != nil || merr != nil || serr != nil {
+			return "", fmt.Errorf("Errors parsing metricAggregationInterval: %v, %v, %v", herr, merr, serr)
+		}
+
+		starttime = time.Now().Add(-(time.Duration(hours)*time.Hour + time.Duration(minutes)*time.Minute + time.Duration(seconds)*time.Second)).UTC().Format(time.RFC3339)
+	}
+	return fmt.Sprintf("%s/%s", starttime, endtime), nil
 }
diff --git a/pkg/scalers/azure_monitor_scaler.go b/pkg/scalers/azure_monitor_scaler.go
index 0627529a3a1..0d84c01f6e3 100644
--- a/pkg/scalers/azure_monitor_scaler.go
+++ b/pkg/scalers/azure_monitor_scaler.go
@@ -112,7 +112,6 @@ func parseAzureMonitorMetadata(metadata, resolvedEnv, authParams map[string]stri
 			if len(aggregationInterval) != 3 {
 				return nil, fmt.Errorf("metricAggregationInterval not in the correct format. Should be hh:mm:ss")
 			}
-
 			meta.aggregationInterval = val
 		}
 	}