CORS-4230: Add a firewall spec and the ability to manage or unmanaged firewall rule creation

api:

Add API changes to Skip firewall rule creation. When unmanaged, the firewall rules will not be
created. When this is the case, the firewall rules should exist prior to creating the network.
This will allow ServiceAccounts to skip the rules:

compute.firewalls.create

cloud:

Update the services and interfaces. The firewall service will no longer create firewall rules when
the firewall policy is set to unmanaged OR when a shared vpc is used during installation and resource creation.

Author: barbacbd

api/v1beta1/types.go

@@ -107,6 +107,33 @@ type Network struct {
 	APIInternalForwardingRule *string `json:"apiInternalForwardingRule,omitempty"`
 }
 
+// FirewallSpec contains configuration for the firewall.
+type FirewallSpec struct {
+	// RulesManagement determines the management policy for firewall rules.
+	// "Managed": The controller will create and manage firewall rules.
+	// "Unmanaged": The controller will not touch any firewall rules. If this is
+	//              changed to "Off" after rules have been created, they will not be
+	//              deleted.
+	// Defaults to "Managed".
+	// +optional
+	// +kubebuilder:default:="Managed"
+	RulesManagement RulesManagementPolicy `json:"rulesManagement,omitempty"`
+}
+
+// RulesManagementPolicy is a string enum type for managing firewall rules.
+// +kubebuilder:validation:Enum=Managed;Unmanaged
+type RulesManagementPolicy string
+
+const (
+	// RulesManagementManaged indicates that the controller should create and manage
+	// firewall rules. This is the default behavior.
+	RulesManagementManaged RulesManagementPolicy = "Managed"
+
+	// RulesManagementUnmanaged indicates that the controller should not create or manage
+	// any firewall rules. If rules already exist, they will be left as-is.
+	RulesManagementUnmanaged RulesManagementPolicy = "Unmanaged"
+)
+
 // NetworkSpec encapsulates all things related to a GCP network.
 type NetworkSpec struct {
 	// Name is the name of the network to be used.
@@ -137,6 +164,10 @@ type NetworkSpec struct {
 	// +optional
 	HostProject *string `json:"hostProject,omitempty"`
 
+	// Firewall configuration.
+	// +optional
+	Firewall FirewallSpec `json:"firewall,omitempty"`
+
 	// Mtu: Maximum Transmission Unit in bytes. The minimum value for this field is
 	// 1300 and the maximum value is 8896. The suggested value is 1500, which is
 	// the default MTU used on the Internet, or 8896 if you want to use Jumbo

api/v1beta1/zz_generated.deepcopy.go

@@ -58,6 +58,7 @@ type ClusterGetter interface {
 	NetworkName() string
 	NetworkProject() string
 	IsSharedVpc() bool
+	SkipFirewallRuleCreation() bool
 	Network() *infrav1.Network
 	AdditionalLabels() infrav1.Labels
 	FailureDomains() clusterv1.FailureDomains

cloud/interfaces.go

@@ -106,6 +106,12 @@ func (s *ClusterScope) NetworkProject() string {
 	return ptr.Deref(s.GCPCluster.Spec.Network.HostProject, s.Project())
 }
 
+// SkipFirewallRuleCreation returns whether the spec indicates that firewall rules
+// should be created or not.
+func (s *ClusterScope) SkipFirewallRuleCreation() bool {
+	return (s.GCPCluster.Spec.Network.Firewall.RulesManagement == infrav1.RulesManagementUnmanaged) || s.IsSharedVpc()
+}
+
 // IsSharedVpc returns true If sharedVPC used else , returns false.
 func (s *ClusterScope) IsSharedVpc() bool {
 	return s.NetworkProject() != s.Project()

cloud/scope/cluster.go

@@ -129,6 +129,12 @@ func (s *ManagedClusterScope) NetworkProject() string {
 	return ptr.Deref(s.GCPManagedCluster.Spec.Network.HostProject, s.Project())
 }
 
+// SkipFirewallRuleCreation returns whether the spec indicates that firewall rules
+// should be created or not.
+func (s *ManagedClusterScope) SkipFirewallRuleCreation() bool {
+	return (s.GCPManagedCluster.Spec.Network.Firewall.RulesManagement == infrav1.RulesManagementUnmanaged) || s.IsSharedVpc()
+}
+
 // IsSharedVpc returns true If sharedVPC used else , returns false.
 func (s *ManagedClusterScope) IsSharedVpc() bool {
 	return s.NetworkProject() != s.Project()

cloud/scope/managedcluster.go

@@ -28,8 +28,8 @@ import (
 // Reconcile reconcile cluster firewall compoenents.
 func (s *Service) Reconcile(ctx context.Context) error {
 	log := log.FromContext(ctx)
-	if s.scope.IsSharedVpc() {
-		log.V(2).Info("Shared VPC enabled. Ignore Reconciling firewall resources")
+	if s.scope.SkipFirewallRuleCreation() {
+		log.V(2).Info("Ignore Reconciling firewall resources")
 		return nil
 	}
 	log.Info("Reconciling firewall resources")

cloud/services/compute/firewalls/reconcile.go

@@ -109,6 +109,34 @@ var fakeGCPClusterSharedVPC = &infrav1.GCPCluster{
 	},
 }
 
+var fakeGCPClusterUnmanagedFirewalls = &infrav1.GCPCluster{
+	ObjectMeta: metav1.ObjectMeta{
+		Name:      "my-cluster",
+		Namespace: "default",
+	},
+	Spec: infrav1.GCPClusterSpec{
+		Project: "my-proj",
+		Region:  "us-central1",
+		Network: infrav1.NetworkSpec{
+			Name: ptr.To("my-network"),
+			Subnets: infrav1.Subnets{
+				infrav1.SubnetSpec{
+					Name:      "workers",
+					CidrBlock: "10.0.0.1/28",
+					Region:    "us-central1",
+					Purpose:   ptr.To[string]("INTERNAL_HTTPS_LOAD_BALANCER"),
+				},
+			},
+			Firewall: infrav1.FirewallSpec{
+				RulesManagement: infrav1.RulesManagementUnmanaged,
+			},
+		},
+	},
+	Status: infrav1.GCPClusterStatus{
+		Network: infrav1.Network{},
+	},
+}
+
 type testCase struct {
 	name          string
 	scope         func() Scope
@@ -146,6 +174,18 @@ func TestService_Reconcile(t *testing.T) {
 		t.Fatal(err)
 	}
 
+	clusterScopeUnmanagedFirewalls, err := scope.NewClusterScope(context.TODO(), scope.ClusterScopeParams{
+		Client:     fakec,
+		Cluster:    fakeCluster,
+		GCPCluster: fakeGCPClusterUnmanagedFirewalls,
+		GCPServices: scope.GCPServices{
+			Compute: &compute.Service{},
+		},
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+
 	tests := []testCase{
 		{
 			name:  "firewall rule does not exist successful create",
@@ -211,6 +251,16 @@ func TestService_Reconcile(t *testing.T) {
 				},
 			},
 		},
+		{
+			name:  "firewall return no error using unmanaged firewall settings",
+			scope: func() Scope { return clusterScopeUnmanagedFirewalls },
+			mockFirewalls: &cloud.MockFirewalls{
+				ProjectRouter: &cloud.SingleProjectRouter{ID: "my-proj"},
+				Objects: map[meta.Key]*cloud.MockFirewallsObj{
+					*meta.GlobalKey(fmt.Sprintf("allow-%s-healthchecks", fakeGCPCluster.Name)): {},
+				},
+			},
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {

cloud/services/compute/firewalls/reconcile_test.go

@@ -179,6 +179,23 @@ spec:
 
                       Defaults to true.
                     type: boolean
+                  firewall:
+                    description: Firewall configuration.
+                    properties:
+                      rulesManagement:
+                        default: Managed
+                        description: |-
+                          RulesManagement determines the management policy for firewall rules.
+                          "Managed": The controller will create and manage firewall rules.
+                          "Unmanaged": The controller will not touch any firewall rules. If this is
+                                       changed to "Off" after rules have been created, they will not be
+                                       deleted.
+                          Defaults to "Managed".
+                        enum:
+                        - Managed
+                        - Unmanaged
+                        type: string
+                    type: object
                   hostProject:
                     description: HostProject is the name of the project hosting the
                       shared VPC network resources.

config/crd/bases/infrastructure.cluster.x-k8s.io_gcpclusters.yaml

@@ -198,6 +198,23 @@ spec:
 
                               Defaults to true.
                             type: boolean
+                          firewall:
+                            description: Firewall configuration.
+                            properties:
+                              rulesManagement:
+                                default: Managed
+                                description: |-
+                                  RulesManagement determines the management policy for firewall rules.
+                                  "Managed": The controller will create and manage firewall rules.
+                                  "Unmanaged": The controller will not touch any firewall rules. If this is
+                                               changed to "Off" after rules have been created, they will not be
+                                               deleted.
+                                  Defaults to "Managed".
+                                enum:
+                                - Managed
+                                - Unmanaged
+                                type: string
+                            type: object
                           hostProject:
                             description: HostProject is the name of the project hosting
                               the shared VPC network resources.

config/crd/bases/infrastructure.cluster.x-k8s.io_gcpclustertemplates.yaml

@@ -175,6 +175,23 @@ spec:
 
                       Defaults to true.
                     type: boolean
+                  firewall:
+                    description: Firewall configuration.
+                    properties:
+                      rulesManagement:
+                        default: Managed
+                        description: |-
+                          RulesManagement determines the management policy for firewall rules.
+                          "Managed": The controller will create and manage firewall rules.
+                          "Unmanaged": The controller will not touch any firewall rules. If this is
+                                       changed to "Off" after rules have been created, they will not be
+                                       deleted.
+                          Defaults to "Managed".
+                        enum:
+                        - Managed
+                        - Unmanaged
+                        type: string
+                    type: object
                   hostProject:
                     description: HostProject is the name of the project hosting the
                       shared VPC network resources.