fix: allow the header based session persistence not to have AbsoluteTimeout (kubernetes-sigs#3215)

Author: sanposhiho

apis/v1/shared_types.go

@@ -745,7 +745,7 @@ const (
 )
 
 // SessionPersistence defines the desired state of SessionPersistence.
-// +kubebuilder:validation:XValidation:message="AbsoluteTimeout must be specified when cookie lifetimeType is Permanent",rule="!has(self.cookieConfig.lifetimeType) || self.cookieConfig.lifetimeType != 'Permanent' || has(self.absoluteTimeout)"
+// +kubebuilder:validation:XValidation:message="AbsoluteTimeout must be specified when cookie lifetimeType is Permanent",rule="!has(self.cookieConfig) || !has(self.cookieConfig.lifetimeType) || self.cookieConfig.lifetimeType != 'Permanent' || has(self.absoluteTimeout)"
 type SessionPersistence struct {
 	// SessionName defines the name of the persistent session token
 	// which may be reflected in the cookie or the header. Users

config/crd/experimental/gateway.networking.k8s.io_backendlbpolicies.yaml

@@ -487,7 +487,7 @@ type BackendLBPolicySpec struct {
 
 // SessionPersistence defines the desired state of
 // SessionPersistence.
-// +kubebuilder:validation:XValidation:rule="!has(self.cookieConfig.lifetimeType) || self.cookieConfig.lifetimeType != 'Permanent' || has(self.absoluteTimeout)",message="AbsoluteTimeout must be specified when cookie lifetimeType is Permanent"
+// +kubebuilder:validation:XValidation:message="AbsoluteTimeout must be specified when cookie lifetimeType is Permanent",rule="!has(self.cookieConfig) || !has(self.cookieConfig.lifetimeType) || self.cookieConfig.lifetimeType != 'Permanent' || has(self.absoluteTimeout)"
 type SessionPersistence struct {
     // SessionName defines the name of the persistent session token
     // which may be reflected in the cookie or the header. Users

config/crd/experimental/gateway.networking.k8s.io_grpcroutes.yaml

@@ -80,6 +80,14 @@ func TestBackendLBPolicyConfig(t *testing.T) {
 			},
 			wantErrors: []string{},
 		},
+		{
+			name: "valid BackendLBPolicyConfig header-based session persistence",
+			sessionPersistence: gatewayv1a2.SessionPersistence{
+				SessionName: ptrTo("foo"),
+				Type:        ptrTo(gatewayv1.HeaderBasedSessionPersistence),
+			},
+			wantErrors: []string{},
+		},
 	}
 	for _, tc := range tests {
 		t.Run(tc.name, func(t *testing.T) {