Fix CNS IP demand overcounting by filtering terminal Pods in IPAMv2

Co-authored-by: rejain456 <[email protected]>

Author: Copilot

cns/ipampool/v2/adapter.go

@@ -31,6 +31,14 @@ func (m *adapter) GetStateSnapshot() cns.IpamPoolMonitorStateSnapshot {
 
 func PodIPDemandListener(ch chan<- int) func([]v1.Pod) {
 	return func(pods []v1.Pod) {
-		ch <- len(pods)
+		// Filter out Pods in terminal phases (Succeeded/Failed) since they no longer
+		// have network sandboxes and don't contribute to IP demand
+		activePods := 0
+		for _, pod := range pods {
+			if pod.Status.Phase != v1.PodSucceeded && pod.Status.Phase != v1.PodFailed {
+				activePods++
+			}
+		}
+		ch <- activePods
 	}
 }

cns/ipampool/v2/adapter_test.go

@@ -0,0 +1,100 @@
+package v2
+
+import (
+	"testing"
+
+	v1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+func TestPodIPDemandListener(t *testing.T) {
+	tests := []struct {
+		name     string
+		pods     []v1.Pod
+		expected int
+	}{
+		{
+			name:     "empty pod list",
+			pods:     []v1.Pod{},
+			expected: 0,
+		},
+		{
+			name: "single running pod",
+			pods: []v1.Pod{
+				{
+					ObjectMeta: metav1.ObjectMeta{Name: "pod1"},
+					Status:     v1.PodStatus{Phase: v1.PodRunning},
+				},
+			},
+			expected: 1,
+		},
+		{
+			name: "multiple running pods",
+			pods: []v1.Pod{
+				{
+					ObjectMeta: metav1.ObjectMeta{Name: "pod1"},
+					Status:     v1.PodStatus{Phase: v1.PodRunning},
+				},
+				{
+					ObjectMeta: metav1.ObjectMeta{Name: "pod2"},
+					Status:     v1.PodStatus{Phase: v1.PodPending},
+				},
+			},
+			expected: 2,
+		},
+		{
+			name: "mix of running and terminal pods - should exclude terminal",
+			pods: []v1.Pod{
+				{
+					ObjectMeta: metav1.ObjectMeta{Name: "pod1"},
+					Status:     v1.PodStatus{Phase: v1.PodRunning},
+				},
+				{
+					ObjectMeta: metav1.ObjectMeta{Name: "pod2"},
+					Status:     v1.PodStatus{Phase: v1.PodSucceeded},
+				},
+				{
+					ObjectMeta: metav1.ObjectMeta{Name: "pod3"},
+					Status:     v1.PodStatus{Phase: v1.PodFailed},
+				},
+				{
+					ObjectMeta: metav1.ObjectMeta{Name: "pod4"},
+					Status:     v1.PodStatus{Phase: v1.PodPending},
+				},
+			},
+			expected: 2, // Only pod1 (Running) and pod4 (Pending) should be counted
+		},
+		{
+			name: "only terminal pods - should count zero",
+			pods: []v1.Pod{
+				{
+					ObjectMeta: metav1.ObjectMeta{Name: "pod1"},
+					Status:     v1.PodStatus{Phase: v1.PodSucceeded},
+				},
+				{
+					ObjectMeta: metav1.ObjectMeta{Name: "pod2"},
+					Status:     v1.PodStatus{Phase: v1.PodFailed},
+				},
+			},
+			expected: 0,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			ch := make(chan int, 1)
+			listener := PodIPDemandListener(ch)
+
+			listener(tt.pods)
+
+			select {
+			case result := <-ch:
+				if result != tt.expected {
+					t.Errorf("expected %d, got %d", tt.expected, result)
+				}
+			default:
+				t.Error("expected value in channel")
+			}
+		})
+	}
+}