Refactor NAT gateway spec into async service interface

azure/scope/cluster.go

@@ -38,6 +38,7 @@ import (
 	infrav1 "sigs.k8s.io/cluster-api-provider-azure/api/v1beta1"
 	"sigs.k8s.io/cluster-api-provider-azure/azure"
 	"sigs.k8s.io/cluster-api-provider-azure/azure/services/groups"
+	"sigs.k8s.io/cluster-api-provider-azure/azure/services/natgateways"
 	"sigs.k8s.io/cluster-api-provider-azure/azure/services/vnetpeerings"
 	"sigs.k8s.io/cluster-api-provider-azure/util/futures"
 	"sigs.k8s.io/cluster-api-provider-azure/util/tele"
@@ -230,14 +231,17 @@ func (s *ClusterScope) RouteTableSpecs() []azure.RouteTableSpec {
 }
 
 // NatGatewaySpecs returns the node nat gateway.
-func (s *ClusterScope) NatGatewaySpecs() []azure.NatGatewaySpec {
-	natGateways := []azure.NatGatewaySpec{}
+func (s *ClusterScope) NatGatewaySpecs() []azure.ResourceSpecGetter {
+	natGateways := []azure.ResourceSpecGetter{}
 
 	// We ignore the control plane nat gateway, as we will always use a LB to enable egress on the control plane.
 	for _, subnet := range s.NodeSubnets() {
 		if subnet.IsNatGatewayEnabled() {
-			natGateways = append(natGateways, azure.NatGatewaySpec{
-				Name: subnet.NatGateway.Name,
+			natGateways = append(natGateways, &natgateways.NatGatewaySpec{
+				Name:           subnet.NatGateway.Name,
+				ResourceGroup:  s.ResourceGroup(),
+				SubscriptionID: s.SubscriptionID(),
+				Location:       s.Location(),
 				NatGatewayIP: infrav1.PublicIPSpec{
 					Name: subnet.NatGateway.NatGatewayIP.Name,
 				},

azure/services/natgateways/client.go

@@ -18,19 +18,26 @@ package natgateways
 
 import (
 	"context"
+	"encoding/json"
 
-	"github.com/Azure/azure-sdk-for-go/services/network/mgmt/2019-06-01/network"
+	"github.com/Azure/azure-sdk-for-go/services/network/mgmt/2021-02-01/network"
 	"github.com/Azure/go-autorest/autorest"
+	azureautorest "github.com/Azure/go-autorest/autorest/azure"
+	"github.com/pkg/errors"
 
+	infrav1 "sigs.k8s.io/cluster-api-provider-azure/api/v1beta1"
 	"sigs.k8s.io/cluster-api-provider-azure/azure"
+	"sigs.k8s.io/cluster-api-provider-azure/util/reconciler"
 	"sigs.k8s.io/cluster-api-provider-azure/util/tele"
 )
 
 // client wraps go-sdk.
 type client interface {
 	Get(context.Context, string, string) (network.NatGateway, error)
-	CreateOrUpdate(context.Context, string, string, network.NatGateway) error
-	Delete(context.Context, string, string) error
+	CreateOrUpdateAsync(context.Context, azure.ResourceSpecGetter) (interface{}, azureautorest.FutureAPI, error)
+	DeleteAsync(context.Context, azure.ResourceSpecGetter) (azureautorest.FutureAPI, error)
+	IsDone(context.Context, azureautorest.FutureAPI) (bool, error)
+	Result(context.Context, azureautorest.FutureAPI, string) (interface{}, error)
 }
 
 // azureClient contains the Azure go-sdk Client.
@@ -55,42 +62,127 @@ func netNatGatewaysClient(subscriptionID string, baseURI string, authorizer auto
 
 // Get gets the specified nat gateway.
 func (ac *azureClient) Get(ctx context.Context, resourceGroupName, natGatewayName string) (network.NatGateway, error) {
-	ctx, _, done := tele.StartSpanWithLogger(ctx, "natgateways.AzureClient.Get")
+	ctx, _, done := tele.StartSpanWithLogger(ctx, "natgateways.azureClient.Get")
 	defer done()
 
 	return ac.natgateways.Get(ctx, resourceGroupName, natGatewayName, "")
 }
 
-// CreateOrUpdate create or updates a nat gateway in a specified resource group.
-func (ac *azureClient) CreateOrUpdate(ctx context.Context, resourceGroupName string, natGatewayName string, natGateway network.NatGateway) error {
-	ctx, _, done := tele.StartSpanWithLogger(ctx, "natgateways.AzureClient.CreateOrUpdate")
-	defer done()
+// CreateOrUpdateAsync creates or updates a Nat Gateway asynchronously.
+// It sends a PUT request to Azure and if accepted without error, the func will return a Future which can be used to track the ongoing
+// progress of the operation.
+func (ac *azureClient) CreateOrUpdateAsync(ctx context.Context, spec azure.ResourceSpecGetter) (interface{}, azureautorest.FutureAPI, error) {
+	ctx, span := tele.Tracer().Start(ctx, "natgateways.azureClient.CreateOrUpdateAsync")
+	defer span.End()
+
+	var existingNatGateway interface{}
+
+	if existing, err := ac.Get(ctx, spec.ResourceGroupName(), spec.ResourceName()); err != nil && !azure.ResourceNotFound(err) {
+		return nil, nil, errors.Wrapf(err, "failed to get Nat Gateway %s for %s in %s", spec.ResourceName(), spec.OwnerResourceName(), spec.ResourceGroupName())
+	} else if err == nil {
+		existingNatGateway = existing
+	}
+
+	params, err := spec.Parameters(existingNatGateway)
+	if err != nil {
+		return nil, nil, errors.Wrapf(err, "failed to get desired parameters for Nat Gateway %s", spec.ResourceName())
+	}
 
-	future, err := ac.natgateways.CreateOrUpdate(ctx, resourceGroupName, natGatewayName, natGateway)
+	natGateway, ok := params.(network.NatGateway)
+	if !ok {
+		if params == nil {
+			// nothing to do here.
+			return existingNatGateway, nil, nil
+		}
+		return nil, nil, errors.Errorf("%T is not a network.NatGateway", params)
+	}
+
+	future, err := ac.natgateways.CreateOrUpdate(ctx, spec.ResourceGroupName(), spec.ResourceName(), natGateway)
 	if err != nil {
-		return err
+		return nil, nil, err
 	}
+
+	ctx, cancel := context.WithTimeout(ctx, reconciler.DefaultAzureCallTimeout)
+	defer cancel()
+
 	err = future.WaitForCompletionRef(ctx, ac.natgateways.Client)
 	if err != nil {
-		return err
+		// if an error occurs, return the future.
+		// this means the long-running operation didn't finish in the specified timeout.
+		return nil, &future, err
 	}
-	_, err = future.Result(ac.natgateways)
-	return err
+
+	result, err := future.Result(ac.natgateways)
+
+	// if the operation completed, return a nil future
+	return result, nil, err
 }
 
-// Delete deletes the specified nat gateway.
-func (ac *azureClient) Delete(ctx context.Context, resourceGroupName, natGatewayName string) error {
-	ctx, _, done := tele.StartSpanWithLogger(ctx, "natgateways.AzureClient.Delete")
-	defer done()
+// DeleteAsync deletes a Nat Gateway asynchronously. DeleteAsync sends a DELETE
+// request to Azure and if accepted without error, the func will return a Future which can be used to track the ongoing
+// progress of the operation.
+func (ac *azureClient) DeleteAsync(ctx context.Context, spec azure.ResourceSpecGetter) (azureautorest.FutureAPI, error) {
+	ctx, span := tele.Tracer().Start(ctx, "natgateways.azureClient.Delete")
+	defer span.End()
 
-	future, err := ac.natgateways.Delete(ctx, resourceGroupName, natGatewayName)
+	future, err := ac.natgateways.Delete(ctx, spec.ResourceGroupName(), spec.ResourceName())
 	if err != nil {
-		return err
+		return nil, err
 	}
+
+	ctx, cancel := context.WithTimeout(ctx, reconciler.DefaultAzureCallTimeout)
+	defer cancel()
+
 	err = future.WaitForCompletionRef(ctx, ac.natgateways.Client)
 	if err != nil {
-		return err
+		// if an error occurs, return the future.
+		// this means the long-running operation didn't finish in the specified timeout.
+		return &future, err
 	}
 	_, err = future.Result(ac.natgateways)
-	return err
+	// if the operation completed, return a nil future.
+	return nil, err
+}
+
+// IsDone returns true if the long-running operation has completed.
+func (ac *azureClient) IsDone(ctx context.Context, future azureautorest.FutureAPI) (bool, error) {
+	ctx, span := tele.Tracer().Start(ctx, "natgateways.azureClient.IsDone")
+	defer span.End()
+
+	done, err := future.DoneWithContext(ctx, ac.natgateways)
+	if err != nil {
+		return false, errors.Wrap(err, "failed checking if the operation was complete")
+	}
+
+	return done, nil
+}
+
+// Result fetches the result of a long-running operation future.
+func (ac *azureClient) Result(ctx context.Context, futureData azureautorest.FutureAPI, futureType string) (interface{}, error) {
+	if futureData == nil {
+		return nil, errors.Errorf("cannot get result from nil future")
+	}
+	var result func(client network.NatGatewaysClient) (natGateway network.NatGateway, err error)
+
+	switch futureType {
+	case infrav1.PutFuture:
+		var future *network.NatGatewaysCreateOrUpdateFuture
+		jsonData, err := futureData.MarshalJSON()
+		if err != nil {
+			return nil, errors.Wrap(err, "failed to marshal future")
+		}
+		if err := json.Unmarshal(jsonData, &future); err != nil {
+			return nil, errors.Wrap(err, "failed to unmarshal future data")
+		}
+		result = (*future).Result
+
+	case infrav1.DeleteFuture:
+		// Delete does not return a result Nat Gateway
+		return nil, nil
+
+	default:
+		return nil, errors.Errorf("unknown future type %q", futureType)
+	}
+
+	return result(ac.natgateways)
 }