Support create or update VMSS asynchronously.

staging/src/k8s.io/legacy-cloud-providers/azure/azure_fakes.go

@@ -29,6 +29,7 @@ import (
 	"github.com/Azure/azure-sdk-for-go/services/compute/mgmt/2019-12-01/compute"
 	"github.com/Azure/azure-sdk-for-go/services/network/mgmt/2019-06-01/network"
 	"github.com/Azure/azure-sdk-for-go/services/storage/mgmt/2019-06-01/storage"
+	"github.com/Azure/go-autorest/autorest/azure"
 	"github.com/Azure/go-autorest/autorest/to"
 	"github.com/golang/mock/gomock"
 
@@ -566,6 +567,14 @@ func (fVMSSC *fakeVirtualMachineScaleSetsClient) CreateOrUpdate(ctx context.Cont
 	return nil
 }
 
+func (fVMSSC *fakeVirtualMachineScaleSetsClient) CreateOrUpdateAsync(ctx context.Context, resourceGroupName string, VMScaleSetName string, parameters compute.VirtualMachineScaleSet) (*azure.Future, *retry.Error) {
+	return nil, nil
+}
+
+func (fVMSSC *fakeVirtualMachineScaleSetsClient) WaitForAsyncOperationResult(ctx context.Context, future *azure.Future) (*http.Response, error) {
+	return nil, nil
+}
+
 func (fVMSSC *fakeVirtualMachineScaleSetsClient) Get(ctx context.Context, resourceGroupName string, VMScaleSetName string) (result compute.VirtualMachineScaleSet, err *retry.Error) {
 	fVMSSC.mutex.Lock()
 	defer fVMSSC.mutex.Unlock()

staging/src/k8s.io/legacy-cloud-providers/azure/clients/vmssclient/azure_vmssclient.go

@@ -234,6 +234,49 @@ func (c *Client) CreateOrUpdate(ctx context.Context, resourceGroupName string, V
 	return nil
 }
 
+// CreateOrUpdateAsync sends the request to arm client and DO NOT wait for the response
+func (c *Client) CreateOrUpdateAsync(ctx context.Context, resourceGroupName string, VMScaleSetName string, parameters compute.VirtualMachineScaleSet) (*azure.Future, *retry.Error) {
+	mc := metrics.NewMetricContext("vmss", "create_or_update_async", resourceGroupName, c.subscriptionID, "")
+
+	// Report errors if the client is rate limited.
+	if !c.rateLimiterWriter.TryAccept() {
+		mc.RateLimitedCount()
+		return nil, retry.GetRateLimitError(true, "VMSSCreateOrUpdateAsync")
+	}
+
+	// Report errors if the client is throttled.
+	if c.RetryAfterWriter.After(time.Now()) {
+		mc.ThrottledCount()
+		rerr := retry.GetThrottlingError("VMSSCreateOrUpdateAsync", "client throttled", c.RetryAfterWriter)
+		return nil, rerr
+	}
+
+	resourceID := armclient.GetResourceID(
+		c.subscriptionID,
+		resourceGroupName,
+		"Microsoft.Compute/virtualMachineScaleSets",
+		VMScaleSetName,
+	)
+
+	future, rerr := c.armClient.PutResourceAsync(ctx, resourceID, parameters)
+	mc.Observe(rerr.Error())
+	if rerr != nil {
+		if rerr.IsThrottled() {
+			// Update RetryAfterReader so that no more requests would be sent until RetryAfter expires.
+			c.RetryAfterWriter = rerr.RetryAfter
+		}
+
+		return nil, rerr
+	}
+
+	return future, nil
+}
+
+// WaitForAsyncOperationResult waits for the response of the request
+func (c *Client) WaitForAsyncOperationResult(ctx context.Context, future *azure.Future) (*http.Response, error) {
+	return c.armClient.WaitForAsyncOperationResult(ctx, future, "VMSSWaitForAsyncOperationResult")
+}
+
 // createOrUpdateVMSS creates or updates a VirtualMachineScaleSet.
 func (c *Client) createOrUpdateVMSS(ctx context.Context, resourceGroupName string, VMScaleSetName string, parameters compute.VirtualMachineScaleSet) *retry.Error {
 	resourceID := armclient.GetResourceID(

staging/src/k8s.io/legacy-cloud-providers/azure/clients/vmssclient/interface.go

@@ -20,8 +20,11 @@ package vmssclient
 
 import (
 	"context"
+	"net/http"
 
 	"github.com/Azure/azure-sdk-for-go/services/compute/mgmt/2019-12-01/compute"
+	"github.com/Azure/go-autorest/autorest/azure"
+
 	"k8s.io/legacy-cloud-providers/azure/retry"
 )
 
@@ -43,6 +46,12 @@ type Interface interface {
 	// CreateOrUpdate creates or updates a VirtualMachineScaleSet.
 	CreateOrUpdate(ctx context.Context, resourceGroupName string, VMScaleSetName string, parameters compute.VirtualMachineScaleSet) *retry.Error
 
+	// CreateOrUpdateSync sends the request to arm client and DO NOT wait for the response
+	CreateOrUpdateAsync(ctx context.Context, resourceGroupName string, VMScaleSetName string, parameters compute.VirtualMachineScaleSet) (*azure.Future, *retry.Error)
+
+	// WaitForAsyncOperationResult waits for the response of the request
+	WaitForAsyncOperationResult(ctx context.Context, future *azure.Future) (*http.Response, error)
+
 	// DeleteInstances deletes the instances for a VirtualMachineScaleSet.
 	DeleteInstances(ctx context.Context, resourceGroupName string, vmScaleSetName string, vmInstanceIDs compute.VirtualMachineScaleSetVMInstanceRequiredIDs) *retry.Error
 }