Merge branch 'release-0.15' into automated-backport-of-#2785-origin-r…

…elease-0.15

pkg/discovery/network/generic.go

@@ -191,10 +191,11 @@ func findPodIPRangeFromNodeSpec(ctx context.Context, client controllerClient.Cli
 }
 
 func parseToPodCidr(nodes []corev1.Node) (string, error) {
-	for i := range nodes {
-		if nodes[i].Spec.PodCIDR != "" {
-			return nodes[i].Spec.PodCIDR, nil
-		}
+	// In K8s, each node is typically assigned a unique PodCIDR range for the pods that run on that node.
+	// Each node's PodCIDR is used to allocate IP addresses to the pods scheduled on that node. Only if
+	// the cluster is a single node deployment, we should rely on the node.Spec.PodCIDR as podCIDR of the cluster.
+	if len(nodes) == 1 {
+		return nodes[0].Spec.PodCIDR, nil
 	}
 
 	return "", nil

pkg/discovery/network/generic_test.go

@@ -222,13 +222,12 @@ var _ = Describe("Generic Network", func() {
 		})
 	})
 
-	When("Pod CIDR information exists on a node", func() {
+	When("Pod CIDR information exists on a single node cluster", func() {
 		var clusterNet *network.ClusterNetwork
 
 		BeforeEach(func() {
 			clusterNet = testDiscoverGenericWith(
-				fakeNode("node1", ""),
-				fakeNode("node2", testPodCIDR),
+				fakeNode("node1", testPodCIDR),
 			)
 		})
 
@@ -245,6 +244,21 @@ var _ = Describe("Generic Network", func() {
 		})
 	})
 
+	When("Pod CIDR information exists on a multi node cluster", func() {
+		var clusterNet *network.ClusterNetwork
+
+		BeforeEach(func() {
+			clusterNet = testDiscoverGenericWith(
+				fakeNode("node1", testPodCIDR),
+				fakeNode("node2", testPodCIDR),
+			)
+		})
+
+		It("Should return an empty ClusterNetwork structure with the pod CIDR", func() {
+			Expect(clusterNet.PodCIDRs).To(BeEmpty())
+		})
+	})
+
 	When("Both pod and service CIDR information exists", func() {
 		var clusterNet *network.ClusterNetwork