Improve quota describe output

pkg/api/resource/quantity.go

@@ -190,7 +190,9 @@ func ParseQuantity(str string) (*Quantity, error) {
 	// of an amount.
 	// Arguably, this should be inf.RoundHalfUp (normal rounding), but
 	// that would have the side effect of rounding values < .5m to zero.
-	amount.Round(amount, 3, inf.RoundUp)
+	if v, ok := amount.Unscaled(); v != int64(0) || !ok {
+		amount.Round(amount, 3, inf.RoundUp)
+	}
 
 	// The max is just a simple cap.
 	if amount.Cmp(maxAllowed) > 0 {
@@ -237,6 +239,11 @@ func (q *Quantity) Canonicalize() (string, suffix) {
 		return "0", ""
 	}
 
+	// zero is zero always
+	if q.Amount.Cmp(&inf.Dec{}) == 0 {
+		return "0", ""
+	}
+
 	format := q.Format
 	switch format {
 	case DecimalExponent, DecimalSI:

pkg/api/resource/quantity_test.go

@@ -57,6 +57,26 @@ func TestDec(t *testing.T) {
 	}
 }
 
+// TestQuantityParseZero ensures that when a 0 quantity is passed, its string value is 0
+func TestQuantityParseZero(t *testing.T) {
+	zero := MustParse("0")
+	if expected, actual := "0", zero.String(); expected != actual {
+		t.Errorf("Expected %v, actual %v", expected, actual)
+	}
+}
+
+// Verifies that you get 0 as canonical value if internal value is 0, and not 0<suffix>
+func TestQuantityCanocicalizeZero(t *testing.T) {
+	val := MustParse("1000m")
+	x := val.Amount
+	y := dec(1, 0)
+	z := val.Amount.Sub(x, y)
+	zero := Quantity{z, DecimalSI}
+	if expected, actual := "0", zero.String(); expected != actual {
+		t.Errorf("Expected %v, actual %v", expected, actual)
+	}
+}
+
 func TestQuantityParse(t *testing.T) {
 	table := []struct {
 		input  string

pkg/api/v1beta3/conversion_test.go

@@ -20,9 +20,41 @@ import (
 	"testing"
 
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/api/resource"
 	versioned "github.com/GoogleCloudPlatform/kubernetes/pkg/api/v1beta3"
 )
 
+func TestResourceQuotaStatusConversion(t *testing.T) {
+	// should serialize as "0"
+	expected := resource.NewQuantity(int64(0), resource.DecimalSI)
+	if "0" != expected.String() {
+		t.Errorf("Expected: 0, Actual: %v, do not require units", expected.String())
+	}
+
+	parsed := resource.MustParse("0")
+	if "0" != parsed.String() {
+		t.Errorf("Expected: 0, Actual: %v, do not require units", parsed.String())
+	}
+
+	quota := &api.ResourceQuota{}
+	quota.Status = api.ResourceQuotaStatus{}
+	quota.Status.Hard = api.ResourceList{}
+	quota.Status.Used = api.ResourceList{}
+	quota.Status.Hard[api.ResourcePods] = *expected
+
+	// round-trip the object
+	data, _ := versioned.Codec.Encode(quota)
+	object, _ := versioned.Codec.Decode(data)
+	after := object.(*api.ResourceQuota)
+	actualQuantity := after.Status.Hard[api.ResourcePods]
+	actual := &actualQuantity
+
+	// should be "0", but was "0m"
+	if expected.String() != actual.String() {
+		t.Errorf("Expected %v, Actual %v", expected.String(), actual.String())
+	}
+}
+
 func TestNodeConversion(t *testing.T) {
 	obj, err := versioned.Codec.Decode([]byte(`{"kind":"Minion","apiVersion":"v1beta3"}`))
 	if err != nil {