Add Optional Override API Endpoint

This adds an optional field to the Network API to override what
is being sent back to Cluster API as the API Endpoint for K8S.
This is more of a, Hope you know what you are doing! feature.

Signed-off-by: David ML Brown Jr <[email protected]>

api/v1alpha3/azurecluster_conversion.go

@@ -185,6 +185,8 @@ func Convert_v1alpha3_NetworkSpec_To_v1beta1_NetworkSpec(in *NetworkSpec, out *i
 		}
 	}
 
+	out.OverrideAPIEndpoint = nil
+
 	if err := autoConvert_v1alpha3_LoadBalancerSpec_To_v1beta1_LoadBalancerSpec(&in.APIServerLB, &out.APIServerLB, s); err != nil {
 		return err
 	}

api/v1alpha4/azurecluster_conversion.go

@@ -79,3 +79,19 @@ func Convert_v1beta1_VnetSpec_To_v1alpha4_VnetSpec(in *infrav1beta1.VnetSpec, ou
 func Convert_v1alpha4_VnetSpec_To_v1beta1_VnetSpec(in *VnetSpec, out *infrav1beta1.VnetSpec, s apiconversion.Scope) error {
 	return autoConvert_v1alpha4_VnetSpec_To_v1beta1_VnetSpec(in, out, s)
 }
+
+// Convert_v1alpha4_NetworkSpec_To_v1beta1_NetworkSpec is an autogenerated conversion function.
+func Convert_v1alpha4_NetworkSpec_To_v1beta1_NetworkSpec(in *NetworkSpec, out *infrav1beta1.NetworkSpec, s apiconversion.Scope) error {
+	if err := autoConvert_v1alpha4_NetworkSpec_To_v1beta1_NetworkSpec(in, out, s); err != nil {
+		return err
+	}
+
+	out.OverrideAPIEndpoint = nil
+
+	return nil
+}
+
+// Convert_v1beta1_NetworkSpec_To_v1alpha4_NetworkSpec is an autogenerated conversion function.
+func Convert_v1beta1_NetworkSpec_To_v1alpha4_NetworkSpec(in *infrav1beta1.NetworkSpec, out *NetworkSpec, s apiconversion.Scope) error {
+	return autoConvert_v1beta1_NetworkSpec_To_v1alpha4_NetworkSpec(in, out, s)
+}

api/v1beta1/types.go

@@ -19,6 +19,7 @@ package v1beta1
 import (
 	"github.com/pkg/errors"
 	"k8s.io/apimachinery/pkg/api/resource"
+	clusterv1 "sigs.k8s.io/cluster-api/api/v1beta1"
 )
 
 const (
@@ -75,6 +76,10 @@ type NetworkSpec struct {
 	// +optional
 	APIServerLB LoadBalancerSpec `json:"apiServerLB,omitempty"`
 
+	// override API Endpoint passed back to Cluster API (hope you know what you are doing, good luck!)
+	// +optional
+	OverrideAPIEndpoint *clusterv1.APIEndpoint `json:"overrideAPIEndpoint,omitempty"`
+
 	// NodeOutboundLB is the configuration for the node outbound load balancer.
 	// +optional
 	NodeOutboundLB *LoadBalancerSpec `json:"nodeOutboundLB,omitempty"`

azure/scope/cluster.go

@@ -649,6 +649,10 @@ func (s *ClusterScope) AdditionalTags() infrav1.Tags {
 
 // APIServerPort returns the APIServerPort to use when creating the load balancer.
 func (s *ClusterScope) APIServerPort() int32 {
+	netSpec := s.AzureCluster.Spec.NetworkSpec
+	if netSpec.OverrideAPIEndpoint != nil {
+		return netSpec.OverrideAPIEndpoint.Port
+	}
 	if s.Cluster.Spec.ClusterNetwork != nil && s.Cluster.Spec.ClusterNetwork.APIServerPort != nil {
 		return *s.Cluster.Spec.ClusterNetwork.APIServerPort
 	}
@@ -657,6 +661,10 @@ func (s *ClusterScope) APIServerPort() int32 {
 
 // APIServerHost returns the hostname used to reach the API server.
 func (s *ClusterScope) APIServerHost() string {
+	netSpec := s.AzureCluster.Spec.NetworkSpec
+	if netSpec.OverrideAPIEndpoint != nil && len(netSpec.OverrideAPIEndpoint.Host) > 0 {
+		return netSpec.OverrideAPIEndpoint.Host
+	}
 	if s.IsAPIServerPrivate() {
 		return azure.GeneratePrivateFQDN(s.GetPrivateDNSZoneName())
 	}

azure/scope/cluster_test.go

@@ -96,6 +96,21 @@ func TestAPIServerHost(t *testing.T) {
 			},
 			want: "apiserver.example.private",
 		},
+		{
+			name: "override host returned to cluster api.",
+			azureCluster: infrav1.AzureCluster{
+				Spec: infrav1.AzureClusterSpec{
+					SubscriptionID: fakeSubscriptionID,
+					NetworkSpec: infrav1.NetworkSpec{
+						OverrideAPIEndpoint: &clusterv1.APIEndpoint{
+							Host: "apiserver.example.private",
+							Port: 443,
+						},
+					},
+				},
+			},
+			want: "apiserver.example.private",
+		},
 	}
 
 	for _, tc := range tests {

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

@@ -1788,6 +1788,21 @@ spec:
                         description: LBType defines an Azure load balancer Type.
                         type: string
                     type: object
+                  overrideAPIEndpoint:
+                    description: override API Endpoint passed back to Cluster API
+                      (hope you know what you are doing, good luck!)
+                    properties:
+                      host:
+                        description: The hostname on which the API server is serving.
+                        type: string
+                      port:
+                        description: The port on which the API server is serving.
+                        format: int32
+                        type: integer
+                    required:
+                    - host
+                    - port
+                    type: object
                   privateDNSZoneName:
                     description: PrivateDNSZoneName defines the zone name for the
                       Azure Private DNS.