From fafc631cc84f3e6b4c613a7cd320f3c5e8b332b6 Mon Sep 17 00:00:00 2001
From: nicklesimba <simha.nikhil@gmail.com>
Date: Fri, 21 Jul 2023 15:59:14 -0500
Subject: [PATCH] added comments and a unit test

Signed-off-by: nicklesimba <simha.nikhil@gmail.com>
---
 pkg/reconciler/ip_test.go | 66 +++++++++++++++++++++++++++++++++++++++
 pkg/reconciler/iploop.go  |  2 ++
 2 files changed, 68 insertions(+)

diff --git a/pkg/reconciler/ip_test.go b/pkg/reconciler/ip_test.go
index f76fb6841..19bec9fd2 100644
--- a/pkg/reconciler/ip_test.go
+++ b/pkg/reconciler/ip_test.go
@@ -241,6 +241,72 @@ var _ = Describe("Whereabouts IP reconciler", func() {
 		})
 	})
 
+	Context("reconciling cluster wide IPs - overlapping IPs (ipv6)", func() {
+		const (
+			numberOfPods       = 1
+			ipv6FirstIPInRange = "2001:1b74:0480:60b1:0000:0000:0000:0002"
+			networkName        = "dummyNetwork"
+			networkRange       = "2001:1b74:480:60b1::10/64"
+			poolName           = "dummyPool"
+		)
+
+		var (
+			pods           []*v1.Pod
+			pools          []v1alpha1.IPPool
+			clusterWideIPs []v1alpha1.OverlappingRangeIPReservation
+			wbClient       wbclient.Interface
+		)
+
+		wrapToRuntimeObject := func(pods ...*v1.Pod) []runtime.Object {
+			var runtimeObjects []runtime.Object
+			for _, pod := range pods {
+				runtimeObjects = append(runtimeObjects, pod)
+			}
+			return runtimeObjects
+		}
+
+		BeforeEach(func() {
+			ips := []string{ipv6FirstIPInRange}
+			networks := []string{networkName}
+			for i := 0; i < numberOfPods; i++ {
+				pod := generatePod(namespace, fmt.Sprintf("pod%d", i+1), ipInNetwork{
+					ip:          ips[i],
+					networkName: networks[i%2], // pod1 and pod3 connected to network1; pod2 connected to network2
+				})
+				pods = append(pods, pod)
+			}
+			k8sClientSet = fakek8sclient.NewSimpleClientset(wrapToRuntimeObject(pods...)...)
+		})
+
+		BeforeEach(func() {
+			firstPool := generateIPPoolSpec(networkRange, namespace, poolName, pods[0].GetName())
+			wbClient = fakewbclient.NewSimpleClientset(firstPool)
+			pools = append(pools, *firstPool)
+		})
+
+		BeforeEach(func() {
+			podIPs := []string{ipv6FirstIPInRange}
+			for i := 0; i < numberOfPods; i++ {
+				var clusterWideIP v1alpha1.OverlappingRangeIPReservation
+				ownerPodRef := fmt.Sprintf("%s/%s", namespace, pods[i].GetName())
+				_, err := wbClient.WhereaboutsV1alpha1().OverlappingRangeIPReservations(namespace).Create(context.TODO(), generateClusterWideIPReservation(namespace, podIPs[i], ownerPodRef), metav1.CreateOptions{})
+				Expect(err).NotTo(HaveOccurred())
+				clusterWideIPs = append(clusterWideIPs, clusterWideIP)
+			}
+		})
+
+		It("will not delete an IP address that isn't orphaned after running reconciler", func() {
+			newReconciler, err := NewReconcileLooperWithClient(context.TODO(), kubernetes.NewKubernetesClient(wbClient, k8sClientSet, timeout), timeout)
+			Expect(err).NotTo(HaveOccurred())
+			Expect(newReconciler.ReconcileOverlappingIPAddresses(context.TODO())).To(Succeed())
+
+			expectedClusterWideIPs := 1
+			clusterWideIPAllocations, err := wbClient.WhereaboutsV1alpha1().OverlappingRangeIPReservations(namespace).List(context.TODO(), metav1.ListOptions{})
+			Expect(err).NotTo(HaveOccurred())
+			Expect(clusterWideIPAllocations.Items).To(HaveLen(expectedClusterWideIPs))
+		})
+	})
+
 	Context("a pod in pending state, without an IP in its network-status", func() {
 		const poolName = "pool1"
 
diff --git a/pkg/reconciler/iploop.go b/pkg/reconciler/iploop.go
index 37ac9cb39..c2c79cfc5 100644
--- a/pkg/reconciler/iploop.go
+++ b/pkg/reconciler/iploop.go
@@ -166,6 +166,8 @@ func (rl *ReconcileLooper) findClusterWideIPReservations(ctx context.Context) er
 	for _, clusterWideIPReservation := range clusterWideIPReservations {
 		ip := clusterWideIPReservation.GetName()
 		// De-normalize the IP
+		// In the UpdateOverlappingRangeAllocation function, the IP address is created with a "normalized" name to comply with the k8s api.
+		// We must denormalize here in order to properly look up the IP address in the regular format, which pods use.
 		denormalizedip := strings.ReplaceAll(ip, "-", ":")
 
 		podRef := clusterWideIPReservation.Spec.PodRef