Allow Node SNAT for Static Egress case

Implemented best effort scenario, where in case of
static Egress also, if there is no egress node then
the packets will be sent using normal Node SNAT, as
in case of dynamic Egress.

Signed-off-by: Pulkit Jain <[email protected]>

pkg/agent/controller/egress/egress_controller.go

@@ -88,6 +88,8 @@ var emptyWatch = watch.NewEmptyWatch()
 
 var newIPAssigner = ipassigner.NewIPAssigner
 
+var egressNodeAvailability = hasEgressNode
+
 // egressState keeps the actual state of an Egress that has been realized.
 type egressState struct {
 	// The actual egress IP of the Egress. If it's different from the desired IP, there is an update to EgressIP, and we
@@ -989,6 +991,12 @@ func (c *EgressController) updateEgressStatus(egress *crdv1b1.Egress, egressIP s
 	return nil
 }
 
+func hasEgressNode(egress *crdv1b1.Egress) bool {
+	if egress.Status.EgressNode == "" {
+		return false
+	}
+	return true
+}
 func (c *EgressController) syncEgress(egressName string) error {
 	startTime := time.Now()
 	defer func() {
@@ -1118,39 +1126,41 @@ func (c *EgressController) syncEgress(egressName string) error {
 	}()
 
 	egressIP := net.ParseIP(eState.egressIP)
-	// Install SNAT flows for desired Pods.
-	for pod := range pods {
-		eState.pods.Insert(pod)
-		stalePods.Delete(pod)
+	if egressNodeAvailability(egress) {
+		// Install SNAT flows for desired Pods.
+		for pod := range pods {
+			eState.pods.Insert(pod)
+			stalePods.Delete(pod)
+
+			// If the Egress is not the effective one for the Pod, do nothing.
+			if !c.bindPodEgress(pod, egressName) {
+				continue
+			}
 
-		// If the Egress is not the effective one for the Pod, do nothing.
-		if !c.bindPodEgress(pod, egressName) {
-			continue
-		}
+			// Get the Pod's openflow port.
+			parts := strings.Split(pod, "/")
+			podNamespace, podName := parts[0], parts[1]
+			ifaces := c.ifaceStore.GetContainerInterfacesByPod(podName, podNamespace)
+			if len(ifaces) == 0 {
+				klog.Infof("Interfaces of Pod %s/%s not found", podNamespace, podName)
+				continue
+			}
 
-		// Get the Pod's openflow port.
-		parts := strings.Split(pod, "/")
-		podNamespace, podName := parts[0], parts[1]
-		ifaces := c.ifaceStore.GetContainerInterfacesByPod(podName, podNamespace)
-		if len(ifaces) == 0 {
-			klog.Infof("Interfaces of Pod %s/%s not found", podNamespace, podName)
-			continue
+			ofPort := ifaces[0].OFPort
+			if eState.ofPorts.Has(ofPort) {
+				staleOFPorts.Delete(ofPort)
+				continue
+			}
+			if err := c.ofClient.InstallPodSNATFlows(uint32(ofPort), egressIP, mark); err != nil {
+				return err
+			}
+			eState.ofPorts.Insert(ofPort)
 		}
 
-		ofPort := ifaces[0].OFPort
-		if eState.ofPorts.Has(ofPort) {
-			staleOFPorts.Delete(ofPort)
-			continue
-		}
-		if err := c.ofClient.InstallPodSNATFlows(uint32(ofPort), egressIP, mark); err != nil {
+		// Uninstall SNAT flows for stale Pods.
+		if err := c.uninstallPodFlows(egressName, eState, staleOFPorts, stalePods); err != nil {
 			return err
 		}
-		eState.ofPorts.Insert(ofPort)
-	}
-
-	// Uninstall SNAT flows for stale Pods.
-	if err := c.uninstallPodFlows(egressName, eState, staleOFPorts, stalePods); err != nil {
-		return err
 	}
 	return nil
 }

pkg/agent/controller/egress/egress_controller_test.go

@@ -1101,6 +1101,15 @@ func TestSyncEgress(t *testing.T) {
 			},
 		},
 	}
+
+	egressNodeAvailability := func(egress *crdv1b1.Egress) {
+		return true
+	}
+
+	defer func() {
+		egressNodeAvailability = hasEgressNode
+	}()
+
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			initObjects := []runtime.Object{tt.existingEgress}
@@ -1195,6 +1204,15 @@ func TestPodUpdateShouldSyncEgress(t *testing.T) {
 			{Pod: &cpv1b2.PodReference{Name: "pendingPod", Namespace: "ns1"}},
 		},
 	}
+
+	egressNodeAvailability := func(egress *crdv1b1.Egress) {
+		return true
+	}
+
+	defer func() {
+		egressNodeAvailability = hasEgressNode
+	}()
+
 	c := newFakeController(t, []runtime.Object{egress})
 	stopCh := make(chan struct{})
 	defer close(stopCh)
@@ -1327,6 +1345,15 @@ func TestSyncOverlappingEgress(t *testing.T) {
 			{Pod: &cpv1b2.PodReference{Name: "pod4", Namespace: "ns4"}},
 		},
 	}
+
+	egressNodeAvailability := func(egress *crdv1b1.Egress) {
+		return true
+	}
+
+	defer func() {
+		egressNodeAvailability = hasEgressNode
+	}()
+
 	c := newFakeController(t, []runtime.Object{egress1, egress2, egress3})
 	stopCh := make(chan struct{})
 	defer close(stopCh)