diff --git a/pkg/cloudprovider/providers/azure/azure_controller_vmss.go b/pkg/cloudprovider/providers/azure/azure_controller_vmss.go
new file mode 100644
index 0000000000..9505b2c49b
--- /dev/null
+++ b/pkg/cloudprovider/providers/azure/azure_controller_vmss.go
@@ -0,0 +1,238 @@
+/*
+Copyright 2018 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package azure
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/Azure/azure-sdk-for-go/arm/compute"
+	computepreview "github.com/Azure/azure-sdk-for-go/services/compute/mgmt/2017-12-01/compute"
+	"github.com/golang/glog"
+
+	"k8s.io/apimachinery/pkg/types"
+	"k8s.io/kubernetes/pkg/cloudprovider"
+)
+
+// AttachDisk attaches a vhd to vm
+// the vhd must exist, can be identified by diskName, diskURI, and lun.
+func (ss *scaleSet) AttachDisk(isManagedDisk bool, diskName, diskURI string, nodeName types.NodeName, lun int32, cachingMode compute.CachingTypes) error {
+	ssName, instanceID, vm, err := ss.getVmssVM(string(nodeName))
+	if err != nil {
+		if err == ErrorNotVmssInstance {
+			glog.V(3).Infof("AttachDisk: node %q is not managed by VMSS, retry with availabilitySet", nodeName)
+			return ss.availabilitySet.AttachDisk(isManagedDisk, diskName, diskURI, nodeName, lun, cachingMode)
+		}
+		return err
+	}
+
+	disks := *vm.StorageProfile.DataDisks
+	if isManagedDisk {
+		disks = append(disks,
+			computepreview.DataDisk{
+				Name:         &diskName,
+				Lun:          &lun,
+				Caching:      computepreview.CachingTypes(cachingMode),
+				CreateOption: "attach",
+				ManagedDisk: &computepreview.ManagedDiskParameters{
+					ID: &diskURI,
+				},
+			})
+	} else {
+		disks = append(disks,
+			computepreview.DataDisk{
+				Name: &diskName,
+				Vhd: &computepreview.VirtualHardDisk{
+					URI: &diskURI,
+				},
+				Lun:          &lun,
+				Caching:      computepreview.CachingTypes(cachingMode),
+				CreateOption: "attach",
+			})
+	}
+	vm.StorageProfile.DataDisks = &disks
+
+	ctx, cancel := getContextWithCancel()
+	defer cancel()
+	glog.V(2).Infof("azureDisk - update(%s): vm(%s) - attach disk", ss.resourceGroup, nodeName)
+	resp, err := ss.VirtualMachineScaleSetVMsClient.Update(ctx, ss.resourceGroup, ssName, instanceID, vm)
+	if ss.CloudProviderBackoff && shouldRetryHTTPRequest(resp, err) {
+		glog.V(2).Infof("azureDisk - update(%s) backing off: vm(%s)", ss.resourceGroup, nodeName)
+		retryErr := ss.UpdateVmssVMWithRetry(ctx, ss.resourceGroup, ssName, instanceID, vm)
+		if retryErr != nil {
+			err = retryErr
+			glog.V(2).Infof("azureDisk - update(%s) abort backoff: vm(%s)", ss.resourceGroup, nodeName)
+		}
+	}
+	if err != nil {
+		detail := err.Error()
+		if strings.Contains(detail, errLeaseFailed) || strings.Contains(detail, errDiskBlobNotFound) {
+			// if lease cannot be acquired or disk not found, immediately detach the disk and return the original error
+			glog.Infof("azureDisk - err %s, try detach", detail)
+			ss.DetachDiskByName(diskName, diskURI, nodeName)
+		}
+	} else {
+		glog.V(4).Info("azureDisk - azure attach succeeded")
+		// Invalidate the cache right after updating
+		ss.vmssVMCache.Delete(ss.makeVmssVMName(ssName, instanceID))
+	}
+	return err
+}
+
+// DetachDiskByName detaches a vhd from host
+// the vhd can be identified by diskName or diskURI
+func (ss *scaleSet) DetachDiskByName(diskName, diskURI string, nodeName types.NodeName) error {
+	ssName, instanceID, vm, err := ss.getVmssVM(string(nodeName))
+	if err != nil {
+		if err == ErrorNotVmssInstance {
+			glog.V(3).Infof("DetachDiskByName: node %q is not managed by VMSS, retry with availabilitySet", nodeName)
+			return ss.availabilitySet.DetachDiskByName(diskName, diskURI, nodeName)
+		}
+
+		return err
+	}
+
+	disks := *vm.StorageProfile.DataDisks
+	bFoundDisk := false
+	for i, disk := range disks {
+		if disk.Lun != nil && (disk.Name != nil && diskName != "" && *disk.Name == diskName) ||
+			(disk.Vhd != nil && disk.Vhd.URI != nil && diskURI != "" && *disk.Vhd.URI == diskURI) ||
+			(disk.ManagedDisk != nil && diskURI != "" && *disk.ManagedDisk.ID == diskURI) {
+			// found the disk
+			glog.V(4).Infof("azureDisk - detach disk: name %q uri %q", diskName, diskURI)
+			disks = append(disks[:i], disks[i+1:]...)
+			bFoundDisk = true
+			break
+		}
+	}
+
+	if !bFoundDisk {
+		return fmt.Errorf("detach azure disk failure, disk %s not found, diskURI: %s", diskName, diskURI)
+	}
+
+	vm.StorageProfile.DataDisks = &disks
+	ctx, cancel := getContextWithCancel()
+	defer cancel()
+	glog.V(2).Infof("azureDisk - update(%s): vm(%s) - detach disk", ss.resourceGroup, nodeName)
+	resp, err := ss.VirtualMachineScaleSetVMsClient.Update(ctx, ss.resourceGroup, ssName, instanceID, vm)
+	if ss.CloudProviderBackoff && shouldRetryHTTPRequest(resp, err) {
+		glog.V(2).Infof("azureDisk - update(%s) backing off: vm(%s)", ss.resourceGroup, nodeName)
+		retryErr := ss.UpdateVmssVMWithRetry(ctx, ss.resourceGroup, ssName, instanceID, vm)
+		if retryErr != nil {
+			err = retryErr
+			glog.V(2).Infof("azureDisk - update(%s) abort backoff: vm(%s)", ss.resourceGroup, nodeName)
+		}
+	}
+	if err != nil {
+		glog.Errorf("azureDisk - azure disk detach %q from %s failed, err: %v", diskName, nodeName, err)
+	} else {
+		glog.V(4).Info("azureDisk - azure detach succeeded")
+		// Invalidate the cache right after updating
+		ss.vmssVMCache.Delete(ss.makeVmssVMName(ssName, instanceID))
+	}
+
+	return err
+}
+
+// GetDiskLun finds the lun on the host that the vhd is attached to, given a vhd's diskName and diskURI
+func (ss *scaleSet) GetDiskLun(diskName, diskURI string, nodeName types.NodeName) (int32, error) {
+	_, _, vm, err := ss.getVmssVM(string(nodeName))
+	if err != nil {
+		if err == ErrorNotVmssInstance {
+			glog.V(3).Infof("GetDiskLun: node %q is not managed by VMSS, retry with availabilitySet", nodeName)
+			return ss.availabilitySet.GetDiskLun(diskName, diskURI, nodeName)
+		}
+
+		return -1, err
+	}
+
+	disks := *vm.StorageProfile.DataDisks
+	for _, disk := range disks {
+		if disk.Lun != nil && (disk.Name != nil && diskName != "" && *disk.Name == diskName) ||
+			(disk.Vhd != nil && disk.Vhd.URI != nil && diskURI != "" && *disk.Vhd.URI == diskURI) ||
+			(disk.ManagedDisk != nil && *disk.ManagedDisk.ID == diskURI) {
+			// found the disk
+			glog.V(4).Infof("azureDisk - find disk: lun %d name %q uri %q", *disk.Lun, diskName, diskURI)
+			return *disk.Lun, nil
+		}
+	}
+	return -1, fmt.Errorf("Cannot find Lun for disk %s", diskName)
+}
+
+// GetNextDiskLun searches all vhd attachment on the host and find unused lun
+// return -1 if all luns are used
+func (ss *scaleSet) GetNextDiskLun(nodeName types.NodeName) (int32, error) {
+	_, _, vm, err := ss.getVmssVM(string(nodeName))
+	if err != nil {
+		if err == ErrorNotVmssInstance {
+			glog.V(3).Infof("GetNextDiskLun: node %q is not managed by VMSS, retry with availabilitySet", nodeName)
+			return ss.availabilitySet.GetNextDiskLun(nodeName)
+		}
+
+		return -1, err
+	}
+
+	used := make([]bool, maxLUN)
+	disks := *vm.StorageProfile.DataDisks
+	for _, disk := range disks {
+		if disk.Lun != nil {
+			used[*disk.Lun] = true
+		}
+	}
+	for k, v := range used {
+		if !v {
+			return int32(k), nil
+		}
+	}
+	return -1, fmt.Errorf("All Luns are used")
+}
+
+// DisksAreAttached checks if a list of volumes are attached to the node with the specified NodeName
+func (ss *scaleSet) DisksAreAttached(diskNames []string, nodeName types.NodeName) (map[string]bool, error) {
+	attached := make(map[string]bool)
+	for _, diskName := range diskNames {
+		attached[diskName] = false
+	}
+
+	_, _, vm, err := ss.getVmssVM(string(nodeName))
+	if err != nil {
+		if err == ErrorNotVmssInstance {
+			glog.V(3).Infof("DisksAreAttached: node %q is not managed by VMSS, retry with availabilitySet", nodeName)
+			return ss.availabilitySet.DisksAreAttached(diskNames, nodeName)
+		}
+
+		if err == cloudprovider.InstanceNotFound {
+			// if host doesn't exist, no need to detach
+			glog.Warningf("azureDisk - Cannot find node %q, DisksAreAttached will assume disks %v are not attached to it.",
+				nodeName, diskNames)
+			return attached, nil
+		}
+
+		return attached, err
+	}
+
+	disks := *vm.StorageProfile.DataDisks
+	for _, disk := range disks {
+		for _, diskName := range diskNames {
+			if disk.Name != nil && diskName != "" && *disk.Name == diskName {
+				attached[diskName] = true
+			}
+		}
+	}
+
+	return attached, nil
+}