From 417f650caa2a1243e7eb86953359a4169002d9fe Mon Sep 17 00:00:00 2001
From: Arjun Naik <arjun.rn@gmail.com>
Date: Thu, 10 Jan 2019 11:23:31 +0100
Subject: [PATCH] Handle 0 values in max collector and unknown metric type

---
 pkg/collector/max_collector.go     | 13 +++++++++----
 pkg/collector/skipper_collector.go |  6 ++++--
 pkg/provider/metric_store.go       |  8 ++++++--
 3 files changed, 19 insertions(+), 8 deletions(-)

diff --git a/pkg/collector/max_collector.go b/pkg/collector/max_collector.go
index 5aa2514..34484ea 100644
--- a/pkg/collector/max_collector.go
+++ b/pkg/collector/max_collector.go
@@ -24,7 +24,7 @@ func NewWeightedMaxCollector(interval time.Duration, weight float64, collectors
 
 // GetMetrics gets metrics from all collectors and return the higest value.
 func (c *WeightedMaxCollector) GetMetrics() ([]CollectedMetric, error) {
-	var max CollectedMetric
+	var max *CollectedMetric
 	for _, collector := range c.collectors {
 		values, err := collector.GetMetrics()
 		if err != nil {
@@ -32,14 +32,19 @@ func (c *WeightedMaxCollector) GetMetrics() ([]CollectedMetric, error) {
 		}
 
 		for _, value := range values {
-			if value.Custom.Value.MilliValue() > max.Custom.Value.MilliValue() {
-				max = value
+			if max != nil {
+				if value.Custom.Value.MilliValue() > max.Custom.Value.MilliValue() {
+					max = &value
+				}
+			} else {
+				max = &value
 			}
 		}
 
 	}
 	max.Custom.Value = *resource.NewMilliQuantity(int64(float64(max.Custom.Value.MilliValue())*c.weight), resource.DecimalSI)
-	return []CollectedMetric{max}, nil
+
+	return []CollectedMetric{*max}, nil
 }
 
 // Interval returns the interval at which the collector should run.
diff --git a/pkg/collector/skipper_collector.go b/pkg/collector/skipper_collector.go
index 5e2a807..88c6a84 100644
--- a/pkg/collector/skipper_collector.go
+++ b/pkg/collector/skipper_collector.go
@@ -103,7 +103,10 @@ func (c *SkipperCollector) getCollector() (Collector, error) {
 		return nil, err
 	}
 
-	backendWeight := getMaxWeights(ingress.Annotations, c.config.MetricLabels.MatchLabels[hostLabel])
+	backendWeight := 1.0
+	if c.config.MetricLabels != nil {
+		backendWeight = getMaxWeights(ingress.Annotations, c.config.MetricLabels.MatchLabels[hostLabel])
+	}
 
 	config := c.config
 
@@ -147,7 +150,6 @@ func (c *SkipperCollector) GetMetrics() ([]CollectedMetric, error) {
 	if len(values) != 1 {
 		return nil, fmt.Errorf("expected to only get one metric value, got %d", len(values))
 	}
-
 	value := values[0]
 	return []CollectedMetric{value}, nil
 }
diff --git a/pkg/provider/metric_store.go b/pkg/provider/metric_store.go
index 184ac96..882547b 100644
--- a/pkg/provider/metric_store.go
+++ b/pkg/provider/metric_store.go
@@ -2,6 +2,7 @@ package provider
 
 import (
 	"fmt"
+	"github.com/sirupsen/logrus"
 	"sort"
 	"strings"
 	"sync"
@@ -54,6 +55,8 @@ func (s *MetricStore) Insert(value collector.CollectedMetric) {
 		s.insertCustomMetric(value.Custom, value.Labels)
 	case autoscalingv2beta2.ExternalMetricSourceType:
 		s.insertExternalMetric(value.External)
+	default:
+		logrus.Errorf("value type unknown: %v", value.Type)
 	}
 }
 
@@ -85,7 +88,7 @@ func (s *MetricStore) insertCustomMetric(value custom_metrics.MetricValue, label
 	metrics, ok := s.customMetricsStore[value.Metric.Name]
 	if !ok {
 		s.customMetricsStore[value.Metric.Name] = map[schema.GroupResource]map[string]map[string]customMetricsStoredMetric{
-			groupResource: map[string]map[string]customMetricsStoredMetric{
+			groupResource: {
 				value.DescribedObject.Namespace: map[string]customMetricsStoredMetric{
 					value.DescribedObject.Name: metric,
 				},
@@ -97,7 +100,7 @@ func (s *MetricStore) insertCustomMetric(value custom_metrics.MetricValue, label
 	group, ok := metrics[groupResource]
 	if !ok {
 		metrics[groupResource] = map[string]map[string]customMetricsStoredMetric{
-			value.DescribedObject.Namespace: map[string]customMetricsStoredMetric{
+			value.DescribedObject.Namespace: {
 				value.DescribedObject.Name: metric,
 			},
 		}
@@ -113,6 +116,7 @@ func (s *MetricStore) insertCustomMetric(value custom_metrics.MetricValue, label
 	}
 
 	namespace[value.DescribedObject.Name] = metric
+
 }
 
 // insertExternalMetric inserts an external metric into the store.