Validate load balancer listeners

pkg/webhook/loadbalancer/validator.go

@@ -28,6 +28,10 @@ func NewValidator(vmiCache ctlkubevirtv1.VirtualMachineInstanceCache) admission.
 func (v *validator) Create(_ *admission.Request, newObj runtime.Object) error {
 	lb := newObj.(*lbv1.LoadBalancer)
 
+	if err := checkListeners(lb); err != nil {
+		return fmt.Errorf("create loadbalancer %s/%s failed: %w", lb.Namespace, lb.Name, err)
+	}
+
 	ok, err := v.matchAtLeastOneVmi(lb)
 	if err != nil {
 		return fmt.Errorf("create loadbalancer %s/%s failed: %w", lb.Namespace, lb.Name, err)
@@ -46,6 +50,10 @@ func (v *validator) Update(_ *admission.Request, oldObj, newObj runtime.Object)
 		return nil
 	}
 
+	if err := checkListeners(lb); err != nil {
+		return fmt.Errorf("update loadbalancer %s/%s failed: %w", lb.Namespace, lb.Name, err)
+	}
+
 	ok, err := v.matchAtLeastOneVmi(lb)
 	if err != nil {
 		return fmt.Errorf("update loadbalancer %s/%s failed: %w", lb.Namespace, lb.Name, err)
@@ -84,3 +92,30 @@ func (v *validator) matchAtLeastOneVmi(lb *lbv1.LoadBalancer) (bool, error) {
 
 	return len(vmis) > 0, nil
 }
+
+func checkListeners(lb *lbv1.LoadBalancer) error {
+	nameMap, portMap, backendMap := map[string]bool{}, map[int32]int{}, map[int32]int{}
+	for i, listener := range lb.Spec.Listeners {
+		// check listener name
+		if _, ok := nameMap[listener.Name]; ok {
+			return fmt.Errorf("listener has duplicate name %s", listener.Name)
+		}
+		nameMap[listener.Name] = true
+
+		// check listener port
+		if index, ok := portMap[listener.Port]; ok {
+			return fmt.Errorf("listener %s has duplicate port %d with listener %s", listener.Name,
+				listener.Port, lb.Spec.Listeners[index].Name)
+		}
+		portMap[listener.Port] = i
+
+		// check backend port
+		if index, ok := backendMap[listener.BackendPort]; ok {
+			return fmt.Errorf("listener %s has duplicate backend port %d with listener %s", listener.Name,
+				listener.BackendPort, lb.Spec.Listeners[index].Name)
+		}
+		backendMap[listener.BackendPort] = i
+	}
+
+	return nil
+}

pkg/webhook/loadbalancer/validator_test.go

@@ -0,0 +1,70 @@
+package loadbalancer
+
+import (
+	"testing"
+
+	lbv1 "github.com/harvester/harvester-load-balancer/pkg/apis/loadbalancer.harvesterhci.io/v1beta1"
+)
+
+func TestCheckListeners(t *testing.T) {
+	tests := []struct {
+		name    string
+		lb      *lbv1.LoadBalancer
+		wantErr bool
+	}{
+		{
+			name: "duplicate name",
+			lb: &lbv1.LoadBalancer{
+				Spec: lbv1.LoadBalancerSpec{
+					Listeners: []lbv1.Listener{
+						{Name: "a"},
+						{Name: "a"},
+					},
+				},
+			},
+			wantErr: true,
+		},
+		{
+			name: "duplicate port",
+			lb: &lbv1.LoadBalancer{
+				Spec: lbv1.LoadBalancerSpec{
+					Listeners: []lbv1.Listener{
+						{Name: "a", Port: 80},
+						{Name: "b", Port: 80},
+					},
+				},
+			},
+			wantErr: true,
+		},
+		{
+			name: "duplicate backend port",
+			lb: &lbv1.LoadBalancer{
+				Spec: lbv1.LoadBalancerSpec{
+					Listeners: []lbv1.Listener{
+						{Name: "a", BackendPort: 80},
+						{Name: "b", BackendPort: 80},
+					},
+				},
+			},
+			wantErr: true,
+		},
+		{
+			name: "right case",
+			lb: &lbv1.LoadBalancer{
+				Spec: lbv1.LoadBalancerSpec{
+					Listeners: []lbv1.Listener{
+						{Name: "a", Port: 80, BackendPort: 80},
+						{Name: "b", Port: 81, BackendPort: 81},
+					},
+				},
+			},
+			wantErr: false,
+		},
+	}
+
+	for _, tt := range tests {
+		if err := checkListeners(tt.lb); (err != nil) != tt.wantErr {
+			t.Errorf("%q. checkPorts() error = %v, wantErr %v", tt.name, err, tt.wantErr)
+		}
+	}
+}