fix: skip IPAM init for empty IP annotation and handle nil IPRangeList

- Skip IPAM initialization when pod IP annotation is empty, log warning instead
- Make IPRangeList.Len() nil-safe to prevent panic in GetSubnetIPRangeString
- Add unit test for nil IPRangeList.Separate() behavior

Signed-off-by: zbb88888 <jmdxjsjgcxy@gmail.com>

Author: zbb88888

pkg/controller/init.go

@@ -452,6 +452,10 @@ func (c *Controller) InitIPAM() error {
 				portName := ovs.PodNameToPortName(podName, pod.Namespace, podNet.ProviderName)
 				ip := pod.Annotations[fmt.Sprintf(util.IPAddressAnnotationTemplate, podNet.ProviderName)]
 				mac := pod.Annotations[fmt.Sprintf(util.MacAddressAnnotationTemplate, podNet.ProviderName)]
+				if ip == "" {
+					klog.Warningf("pod %s/%s has empty IP annotation for provider %s, skip IPAM init", pod.Namespace, podName, podNet.ProviderName)
+					continue
+				}
 				_, _, _, err := c.ipam.GetStaticAddress(key, portName, ip, &mac, podNet.Subnet.Name, true)
 				if err != nil {
 					klog.Errorf("failed to init pod %s.%s address %s: %v", podName, pod.Namespace, pod.Annotations[fmt.Sprintf(util.IPAddressAnnotationTemplate, podNet.ProviderName)], err)

pkg/ipam/ip_range_list.go

@@ -85,6 +85,9 @@ func (r *IPRangeList) Clone() *IPRangeList {
 }
 
 func (r *IPRangeList) Len() int {
+	if r == nil {
+		return 0
+	}
 	return len(r.ranges)
 }
 

pkg/ipam/ip_range_list_test.go

@@ -1388,3 +1388,38 @@ func TestIPRangeListToCIDRsEdgeCases(t *testing.T) {
 		require.Equal(t, []string{"::/128"}, result)
 	})
 }
+
+func TestIPRangeListLen_WithNilReceiver(t *testing.T) {
+	// Background: In GetSubnetIPRangeString, subnet.V4Available can be nil for IPv6-only subnets.
+	// Calling Len() on nil receiver must not panic.
+	var nilList *IPRangeList
+	require.NotPanics(t, func() {
+		require.Equal(t, 0, nilList.Len())
+	})
+}
+
+func TestIPRangeListSeparate_WithNilReceiver(t *testing.T) {
+	// Background: In GetSubnetIPRangeString, we call V4Available.Separate(V4Using).
+	// For IPv6-only subnets, V4Available is nil. This must not panic.
+	var nilList *IPRangeList
+	other, err := NewIPRangeListFrom("10.0.0.1..10.0.0.10")
+	require.NoError(t, err)
+
+	var result *IPRangeList
+	require.NotPanics(t, func() {
+		result = nilList.Separate(other)
+	})
+	require.NotNil(t, result)
+	require.Equal(t, 0, result.Len())
+}
+
+func TestIPRangeListSeparate_WithEmptyList(t *testing.T) {
+	// An empty but non-nil list should also return empty result
+	emptyList := NewEmptyIPRangeList()
+	other, err := NewIPRangeListFrom("10.0.0.1..10.0.0.10")
+	require.NoError(t, err)
+
+	result := emptyList.Separate(other)
+	require.NotNil(t, result)
+	require.Equal(t, 0, result.Len())
+}