Consider Pods count in CountIn()

Signed-off-by: Yuki Iwai <[email protected]>

pkg/resources/requests.go

@@ -18,6 +18,7 @@ package resources
 
 import (
 	"maps"
+	"math"
 	"strings"
 
 	corev1 "k8s.io/api/core/v1"
@@ -103,17 +104,27 @@ func ResourceQuantityString(name corev1.ResourceName, v int64) string {
 	return rq.String()
 }
 
-func (req Requests) CountIn(capacity Requests) int32 {
+func (r Requests) CountIn(capacity Requests) int32 {
 	var result *int32
-	for rName, rValue := range req {
-		capacity, found := capacity[rName]
+	// If the capacity does not have Pods count, this assumes the unlimited Pods count capacity.
+	if _, ok := capacity[corev1.ResourcePods]; !ok {
+		capacity[corev1.ResourcePods] = math.MaxInt32
+	}
+	for rName, rValue := range r {
+		rCap, found := capacity[rName]
 		if !found {
 			return 0
 		}
 		// find the minimum count matching all the resource quota.
-		count := int32(capacity / rValue)
+		var count int32
+		switch rName {
+		case corev1.ResourcePods:
+			count = max(int32(rCap-rValue), 0)
+		default:
+			count = int32(rCap / rValue)
+		}
 		if result == nil || count < *result {
-			result = ptr.To(count)
+			result = ptr.To(min(count, int32(capacity[corev1.ResourcePods])))
 		}
 	}
 	return ptr.Deref(result, 0)

pkg/resources/requests_test.go

@@ -80,6 +80,34 @@ func TestCountIn(t *testing.T) {
 			},
 			wantResult: 2,
 		},
+		"requests have Pods count and it is less than capacity": {
+			requests: Requests{
+				corev1.ResourcePods: 1,
+			},
+			capacity: Requests{
+				corev1.ResourcePods: 5,
+			},
+			wantResult: 4,
+		},
+		"requests have Pods count and it is more than capacity": {
+			requests: Requests{
+				corev1.ResourcePods: 2,
+			},
+			capacity: Requests{
+				corev1.ResourcePods: 1,
+			},
+			wantResult: 0,
+		},
+		"requests have Pods count and capacity doesn't have Pods count": {
+			requests: Requests{
+				corev1.ResourceCPU:  4,
+				corev1.ResourcePods: 4,
+			},
+			capacity: Requests{
+				corev1.ResourceCPU: 8,
+			},
+			wantResult: 2,
+		},
 	}
 	for name, tc := range cases {
 		t.Run(name, func(t *testing.T) {