Enable operating on microvalues in addong resizer

Author: wojtek-t

addon-resizer/nanny/estimator.go

@@ -17,6 +17,8 @@ limitations under the License.
 package nanny
 
 import (
+	"fmt"
+
 	api "k8s.io/kubernetes/pkg/api/v1"
 
 	"k8s.io/kubernetes/pkg/api/resource"
@@ -61,10 +63,18 @@ func calculateResources(numNodes uint64, resources []Resource) *api.ResourceRequ
 	limits := make(api.ResourceList)
 	requests := make(api.ResourceList)
 	for _, r := range resources {
-		val := r.Base.MilliValue() + r.ExtraPerNode.MilliValue()*int64(numNodes)
-		newRes := resource.NewMilliQuantity(val, r.Base.Format)
-		limits[r.Name] = *newRes
-		requests[r.Name] = *newRes
+		// Since we want to enable passing values smaller than e.g. 1 millicore per node,
+		// we need to have some more hacky solution here than operating on MilliValues.
+		perNodeString := r.ExtraPerNode.String()
+		var perNode float64
+		read, _ := fmt.Sscanf(perNodeString, "%f", &perNode)
+		overhead := resource.MustParse(fmt.Sprintf("%f%s", perNode*float64(numNodes), perNodeString[read:]))
+
+		newRes := r.Base
+		newRes.Add(overhead)
+
+		limits[r.Name] = newRes
+		requests[r.Name] = newRes
 	}
 	return &api.ResourceRequirements{
 		Limits:   limits,

addon-resizer/nanny/estimator_test.go

@@ -85,6 +85,15 @@ var (
 			},
 		},
 	}
+	lessThanMilliEstimator = LinearEstimator{
+		Resources: []Resource{
+			{
+				Base:         resource.MustParse("0.3"),
+				ExtraPerNode: resource.MustParse("0.5m"),
+				Name:         "cpu",
+			},
+		},
+	}
 	emptyEstimator = LinearEstimator{
 		Resources: []Resource{},
 	}
@@ -145,6 +154,9 @@ var (
 		"cpu":    resource.MustParse("3.3"),
 		"memory": resource.MustParse("33Mi"),
 	}
+	threeNodeLessThanMilliResources = api.ResourceList{
+		"cpu": resource.MustParse("0.3015"),
+	}
 	noResources = api.ResourceList{}
 
 	sixteenNodeResources = api.ResourceList{
@@ -191,6 +203,7 @@ func TestEstimateResources(t *testing.T) {
 		{noMemoryEstimator, 3, threeNodeNoMemoryResources, threeNodeNoMemoryResources},
 		{noStorageEstimator, 0, noStorageBaseResources, noStorageBaseResources},
 		{noStorageEstimator, 3, threeNodeNoStorageResources, threeNodeNoStorageResources},
+		{lessThanMilliEstimator, 3, threeNodeLessThanMilliResources, threeNodeLessThanMilliResources},
 		{emptyEstimator, 0, noResources, noResources},
 		{emptyEstimator, 3, noResources, noResources},
 		{exponentialEstimator, 0, sixteenNodeResources, sixteenNodeResources},