Make pod metrics sum to aggregate resouce usage graphs (kubernetes#1381)

The issue was with different metrics downloaded in the list and in the graphs. The other problem was that "current usage" was off by 15 mins.

Re kubernetes#1346

src/app/backend/resource/common/podmetrics.go

@@ -27,8 +27,8 @@ import (
 )
 
 const (
-	cpuUsage    = "cpu-usage"
-	memoryUsage = "memory-usage"
+	CpuUsage    = "cpu/usage_rate"
+	MemoryUsage = "memory/usage"
 )
 
 // MetricsByPod is a metrics map by pod name.
@@ -66,8 +66,8 @@ func getPodListMetrics(podNamesByNamespace map[string][]string,
 	result := &MetricsByPod{MetricsMap: make(map[string]map[string]PodMetrics)}
 
 	for namespace, podNames := range podNamesByNamespace {
-		metricCPUUsagePath := createMetricPath(namespace, podNames, cpuUsage)
-		metricMemUsagePath := createMetricPath(namespace, podNames, memoryUsage)
+		metricCPUUsagePath := createMetricPath(namespace, podNames, CpuUsage)
+		metricMemUsagePath := createMetricPath(namespace, podNames, MemoryUsage)
 
 		resultCPUUsageRaw, err := getRawMetrics(heapsterClient, metricCPUUsagePath)
 		if err != nil {
@@ -138,11 +138,11 @@ func fillPodMetrics(cpuMetrics []heapster.MetricResult, memMetrics []heapster.Me
 			cpuMetricsList := cpuMetrics[iterator].Metrics
 
 			if len(memMetricsList) > 0 {
-				memValue = &memMetricsList[0].Value
+				memValue = &memMetricsList[len(memMetricsList) - 1].Value
 			}
 
 			if len(cpuMetricsList) > 0 {
-				cpuValue = &cpuMetricsList[0].Value
+				cpuValue = &cpuMetricsList[len(cpuMetricsList) - 1].Value
 			}
 
 			cpuHistory := make([]MetricResult, len(cpuMetricsList))

src/app/backend/resource/dataselect/dataselect.go

@@ -173,7 +173,8 @@ func GenericDataSelect(dataList []DataCell, dsQuery *DataSelectQuery) []DataCell
 }
 
 // GenericDataSelect takes a list of GenericDataCells and DataSelectQuery and returns selected data as instructed by dsQuery.
-func GenericDataSelectWithMetrics(dataList []DataCell, dsQuery *DataSelectQuery, cachedResources *CachedResources, heapsterClient *client.HeapsterClient) ([]DataCell, metric.MetricPromises) {
+func GenericDataSelectWithMetrics(dataList []DataCell, dsQuery *DataSelectQuery,
+	cachedResources *CachedResources, heapsterClient *client.HeapsterClient) ([]DataCell, metric.MetricPromises) {
 	SelectableData := DataSelector{
 		GenericDataList: dataList,
 		DataSelectQuery: dsQuery,

src/app/backend/resource/dataselect/dataselectquery.go

@@ -16,6 +16,7 @@ package dataselect
 
 import (
 	"github.com/kubernetes/dashboard/src/app/backend/resource/metric"
+	"github.com/kubernetes/dashboard/src/app/backend/resource/common"
 )
 
 // Options for GenericDataSelect which takes []GenericDataCell and returns selected data.
@@ -32,7 +33,8 @@ var NoMetrics = NewMetricQuery(nil, nil)
 
 // StandardMetrics query results in a standard metrics being returned.
 // standard metrics are: cpu usage, memory usage and aggregation = sum.
-var StandardMetrics = NewMetricQuery([]string{"cpu/usage_rate", "memory/usage"}, metric.OnlySumAggregation)
+var StandardMetrics = NewMetricQuery([]string{common.CpuUsage, common.MemoryUsage},
+	metric.OnlySumAggregation)
 
 // MetricQuery holds parameters for metric extraction process.
 // It accepts list of metrics to be downloaded and a list of aggregations that should be performed for each metric.

src/app/backend/resource/pod/podlist.go

@@ -105,16 +105,19 @@ func CreatePodList(pods []api.Pod, dsQuery *dataselect.DataSelectQuery,
 		ListMeta: common.ListMeta{TotalItems: len(pods)},
 	}
 
+	cache := &dataselect.CachedResources{Pods: pods}
+
 	podCells, cumulativeMetricsPromises := dataselect.GenericDataSelectWithMetrics(toCells(pods), dsQuery,
-		dataselect.NoResourceCache, &heapsterClient)
+		cache, &heapsterClient)
 	pods = fromCells(podCells)
 
 	for _, pod := range pods {
 		podDetail := ToPod(&pod, metrics)
 		podList.Pods = append(podList.Pods, podDetail)
-	}
 
+	}
 	cumulativeMetrics, err := cumulativeMetricsPromises.GetMetrics()
+
 	podList.CumulativeMetrics = cumulativeMetrics
 	if err != nil {
 		podList.CumulativeMetrics = make([]metric.Metric, 0)

src/test/backend/resource/common/podmetrics_test.go

@@ -61,7 +61,9 @@ func TestUnmarshalMetrics(t *testing.T) {
 func TestCreateResponse(t *testing.T) {
 	var cpuUsage1 uint64 = 1
 	var cpuUsage2 uint64 = 2
+	var cpuUsage3 uint64 = 3
 	var memoryUsage uint64 = 6131712
+	var memoryUsage2 uint64 = 6131713
 	cases := []struct {
 		cpuMetrics []heapster.MetricResult
 		memMetrics []heapster.MetricResult
@@ -89,11 +91,13 @@ func TestCreateResponse(t *testing.T) {
 			}},
 			{Metrics: []heapster.MetricPoint{
 				{Value: cpuUsage2},
+				{Value: cpuUsage3},
 			}},
 		},
 			[]heapster.MetricResult{
 				{Metrics: []heapster.MetricPoint{
 					{Value: memoryUsage},
+					{Value: memoryUsage2},
 				}},
 				{Metrics: []heapster.MetricPoint{
 					{Value: memoryUsage},
@@ -106,14 +110,16 @@ func TestCreateResponse(t *testing.T) {
 					CPUUsageHistory: []MetricResult{
 						{Value: cpuUsage1},
 					},
-					MemoryUsage: &memoryUsage,
+					MemoryUsage: &memoryUsage2,
 					MemoryUsageHistory: []MetricResult{
 						{Value: memoryUsage},
+						{Value: memoryUsage2},
 					},
 				}, "b": {
-					CPUUsage: &cpuUsage2,
+					CPUUsage: &cpuUsage3,
 					CPUUsageHistory: []MetricResult{
 						{Value: cpuUsage2},
+						{Value: cpuUsage3},
 					},
 					MemoryUsage: &memoryUsage,
 					MemoryUsageHistory: []MetricResult{