[NPM] Ignoring hostnetwork pods from being added into Ipsets (#776) (#777)

* Ignoring hostnetwork pods from being added into Ipsets

* generalizing the check on hostnetwork pod

* Adding tests for add, update and delete hostnetwork pods

npm/pod.go

@@ -21,6 +21,10 @@ func isSystemPod(podObj *corev1.Pod) bool {
 	return podObj.ObjectMeta.Namespace == util.KubeSystemFlag
 }
 
+func isHostNetworkPod(podObj *corev1.Pod) bool {
+	return podObj.Spec.HostNetwork
+}
+
 func isInvalidPodUpdate(oldPodObj, newPodObj *corev1.Pod) (isInvalidUpdate bool) {
 	isInvalidUpdate = oldPodObj.ObjectMeta.Namespace == newPodObj.ObjectMeta.Namespace &&
 		oldPodObj.ObjectMeta.Name == newPodObj.ObjectMeta.Name &&
@@ -61,6 +65,12 @@ func (npMgr *NetworkPolicyManager) AddPod(podObj *corev1.Pod) error {
 		}
 	}
 
+	// Ignore adding the HostNetwork pod to any ipsets.
+	if isHostNetworkPod(podObj) {
+		log.Logf("HostNetwork POD IGNORED: [%s%s/%s/%s%+v%s]", podUid, podNs, podName, podNodeName, podLabels, podIP)
+		return nil
+	}
+
 	// Add the pod to its namespace's ipset.
 	log.Logf("Adding pod %s to ipset %s", podIP, podNs)
 	if err = ipsMgr.AddToSet(podNs, podIP, util.IpsetNetHashFlag, podUid); err != nil {
@@ -116,6 +126,17 @@ func (npMgr *NetworkPolicyManager) UpdatePod(oldPodObj, newPodObj *corev1.Pod) e
 		return nil
 	}
 
+	// today K8s does not allow updating HostNetwork flag for an existing Pod. So NPM can safely
+	// check on the oldPodObj for hostNework value
+	if isHostNetworkPod(oldPodObj) {
+		log.Logf(
+			"POD UPDATING ignored for HostNetwork Pod:\n old pod: [%s/%s/%+v/%s/%s]\n new pod: [%s/%s/%+v/%s/%s]",
+			oldPodObj.ObjectMeta.Namespace, oldPodObj.ObjectMeta.Name, oldPodObj.Status.PodIP,
+			newPodObj.ObjectMeta.Namespace, newPodObj.ObjectMeta.Name, newPodObj.Status.PodIP,
+		)
+		return nil
+	}
+
 	if isInvalidPodUpdate(oldPodObj, newPodObj) {
 		return nil
 	}

npm/pod_test.go

@@ -202,3 +202,183 @@ func TestDeletePod(t *testing.T) {
 	}
 	npMgr.Unlock()
 }
+
+func TestAddHostNetworkPod(t *testing.T) {
+	npMgr := &NetworkPolicyManager{
+		nsMap:            make(map[string]*namespace),
+		podMap:           make(map[string]string),
+		TelemetryEnabled: false,
+	}
+
+	allNs, err := newNs(util.KubeAllNamespacesFlag)
+	if err != nil {
+		panic(err.Error)
+	}
+	npMgr.nsMap[util.KubeAllNamespacesFlag] = allNs
+
+	ipsMgr := ipsm.NewIpsetManager()
+	if err := ipsMgr.Save(util.IpsetTestConfigFile); err != nil {
+		t.Errorf("TestAddHostNetworkPod failed @ ipsMgr.Save")
+	}
+
+	defer func() {
+		if err := ipsMgr.Restore(util.IpsetTestConfigFile); err != nil {
+			t.Errorf("TestAddHostNetworkPod failed @ ipsMgr.Restore")
+		}
+	}()
+
+	podObj := &corev1.Pod{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "test-pod",
+			Namespace: "test-namespace",
+			Labels: map[string]string{
+				"app": "test-pod",
+			},
+		},
+		Status: corev1.PodStatus{
+			Phase: "Running",
+			PodIP: "1.2.3.4",
+		},
+		Spec: corev1.PodSpec{
+			HostNetwork: true,
+		},
+	}
+
+	npMgr.Lock()
+	if err := npMgr.AddPod(podObj); err != nil {
+		t.Errorf("TestAddHostNetworkPod failed @ AddPod")
+	}
+
+	if len(npMgr.podMap) >= 1 {
+		t.Errorf("TestAddHostNetworkPod failed @ podMap length check")
+	}
+	npMgr.Unlock()
+}
+
+func TestUpdateHostNetworkPod(t *testing.T) {
+	npMgr := &NetworkPolicyManager{
+		nsMap:            make(map[string]*namespace),
+		podMap:           make(map[string]string),
+		TelemetryEnabled: false,
+	}
+
+	allNs, err := newNs(util.KubeAllNamespacesFlag)
+	if err != nil {
+		panic(err.Error)
+	}
+	npMgr.nsMap[util.KubeAllNamespacesFlag] = allNs
+
+	ipsMgr := ipsm.NewIpsetManager()
+	if err := ipsMgr.Save(util.IpsetTestConfigFile); err != nil {
+		t.Errorf("TestUpdateHostNetworkPod failed @ ipsMgr.Save")
+	}
+
+	defer func() {
+		if err := ipsMgr.Restore(util.IpsetTestConfigFile); err != nil {
+			t.Errorf("TestUpdateHostNetworkPod failed @ ipsMgr.Restore")
+		}
+	}()
+
+	// HostNetwork check is done on the oldPodObj,
+	// so intentionally not adding hostnet true in newPodObj
+	oldPodObj := &corev1.Pod{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "old-test-pod",
+			Namespace: "test-namespace",
+			Labels: map[string]string{
+				"app": "old-test-pod",
+			},
+		},
+		Status: corev1.PodStatus{
+			Phase: "Running",
+			PodIP: "1.2.3.4",
+		},
+		Spec: corev1.PodSpec{
+			HostNetwork: true,
+		},
+	}
+
+	newPodObj := &corev1.Pod{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "new-test-pod",
+			Namespace: "test-namespace",
+			Labels: map[string]string{
+				"app": "new-test-pod",
+			},
+		},
+		Status: corev1.PodStatus{
+			Phase: "Running",
+			PodIP: "4.3.2.1",
+		},
+	}
+
+	npMgr.Lock()
+	if err := npMgr.AddPod(oldPodObj); err != nil {
+		t.Errorf("TestUpdateHostNetworkPod failed @ AddPod")
+	}
+
+	if err := npMgr.UpdatePod(oldPodObj, newPodObj); err != nil {
+		t.Errorf("TestUpdateHostNetworkPod failed @ UpdatePod")
+	}
+
+	if len(npMgr.podMap) >= 1 {
+		t.Errorf("TestUpdateHostNetworkPod failed @ podMap length check")
+	}
+	npMgr.Unlock()
+}
+
+func TestDeleteHostNetworkPod(t *testing.T) {
+	npMgr := &NetworkPolicyManager{
+		nsMap:            make(map[string]*namespace),
+		podMap:           make(map[string]string),
+		TelemetryEnabled: false,
+	}
+
+	allNs, err := newNs(util.KubeAllNamespacesFlag)
+	if err != nil {
+		panic(err.Error)
+	}
+	npMgr.nsMap[util.KubeAllNamespacesFlag] = allNs
+
+	ipsMgr := ipsm.NewIpsetManager()
+	if err := ipsMgr.Save(util.IpsetTestConfigFile); err != nil {
+		t.Errorf("TestDeleteHostNetworkPod failed @ ipsMgr.Save")
+	}
+
+	defer func() {
+		if err := ipsMgr.Restore(util.IpsetTestConfigFile); err != nil {
+			t.Errorf("TestDeleteHostNetworkPod failed @ ipsMgr.Restore")
+		}
+	}()
+
+	podObj := &corev1.Pod{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "test-pod",
+			Namespace: "test-namespace",
+			Labels: map[string]string{
+				"app": "test-pod",
+			},
+		},
+		Status: corev1.PodStatus{
+			Phase: "Running",
+			PodIP: "1.2.3.4",
+		},
+		Spec: corev1.PodSpec{
+			HostNetwork: true,
+		},
+	}
+
+	npMgr.Lock()
+	if err := npMgr.AddPod(podObj); err != nil {
+		t.Errorf("TestDeleteHostNetworkPod failed @ AddPod")
+	}
+
+	if len(npMgr.podMap) >= 1 {
+		t.Errorf("TestDeleteHostNetworkPod failed @ podMap length check")
+	}
+
+	if err := npMgr.DeletePod(podObj); err != nil {
+		t.Errorf("TestDeleteHostNetworkPod failed @ DeletePod")
+	}
+	npMgr.Unlock()
+}