Merge pull request #66553 from feiskyer/azure-disk-availablity-zone

Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Add availability zones support to Azure managed disks

**What this PR does / why we need it**:

Continue of [Azure Availability Zone feature](https://github.com/kubernetes/features/issues/586).

This PR adds availability zone support for Azure managed disks and its storage class. Zoned managed disks is enabled by default if there are zoned nodes in the cluster.

The zone could also be customized by `zone` or `zones` parameter, e.g.

```yaml
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  annotations:
  name: managed-disk-zone-1
parameters:
  zone: "southeastasia-1"
  # zones: "southeastasia-1,"southeastasia-2"
  cachingmode: None
  kind: Managed
  storageaccounttype: Standard_LRS
provisioner: kubernetes.io/azure-disk
reclaimPolicy: Delete
volumeBindingMode: Immediate
```

All zoned AzureDisk PV will also be labeled with its availability zone, e.g.

```sh
$ kubectl get pvc pvc-azuredisk-az-1
NAME                 STATUS    VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS          AGE
pvc-azuredisk-az-1   Bound     pvc-5ad0c7b8-8f0b-11e8-94f2-000d3a07de8c   5Gi        RWO            managed-disk-zone-1   2h

$ kubectl get pv pvc-5ad0c7b8-8f0b-11e8-94f2-000d3a07de8c --show-labels
NAME                                       CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS    CLAIM                        STORAGECLASS          REASON    AGE       LABELS
pvc-5ad0c7b8-8f0b-11e8-94f2-000d3a07de8c   5Gi        RWO            Delete           Bound     default/pvc-azuredisk-az-1   managed-disk-zone-1             2h        failure-domain.beta.kubernetes.io/region=southeastasia,failure-domain.beta.kubernetes.io/zone=southeastasia-1
```

**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
Fixes #

**Special notes for your reviewer**:

See also the [KEP](https://github.com/kubernetes/community/pull/2364).

DynamicProvisioningScheduling feature would be added in a following PR.

**Release note**:

```release-note
Azure managed disks now support availability zones and new parameters `zoned`, `zone` and `zones` are added for AzureDisk storage class.
```

/kind feature
/sig azure
/assign @brendandburns @khenidak @andyzhangx

plugin/pkg/admission/storage/persistentvolume/label/BUILD

@@ -17,6 +17,7 @@ go_library(
         "//pkg/apis/core:go_default_library",
         "//pkg/cloudprovider:go_default_library",
         "//pkg/cloudprovider/providers/aws:go_default_library",
+        "//pkg/cloudprovider/providers/azure:go_default_library",
         "//pkg/cloudprovider/providers/gce:go_default_library",
         "//pkg/features:go_default_library",
         "//pkg/kubeapiserver/admission:go_default_library",

plugin/pkg/admission/storage/persistentvolume/label/admission.go

@@ -28,6 +28,7 @@ import (
 	api "k8s.io/kubernetes/pkg/apis/core"
 	"k8s.io/kubernetes/pkg/cloudprovider"
 	"k8s.io/kubernetes/pkg/cloudprovider/providers/aws"
+	"k8s.io/kubernetes/pkg/cloudprovider/providers/azure"
 	"k8s.io/kubernetes/pkg/cloudprovider/providers/gce"
 	"k8s.io/kubernetes/pkg/features"
 	kubeapiserveradmission "k8s.io/kubernetes/pkg/kubeapiserver/admission"
@@ -58,6 +59,7 @@ type persistentVolumeLabel struct {
 	ebsVolumes       aws.Volumes
 	cloudConfig      []byte
 	gceCloudProvider *gce.GCECloud
+	azureProvider    *azure.Cloud
 }
 
 var _ admission.MutationInterface = &persistentVolumeLabel{}
@@ -69,7 +71,7 @@ var _ kubeapiserveradmission.WantsCloudConfig = &persistentVolumeLabel{}
 // As a side effect, the cloud provider may block invalid or non-existent volumes.
 func newPersistentVolumeLabel() *persistentVolumeLabel {
 	// DEPRECATED: cloud-controller-manager will now start NewPersistentVolumeLabelController
-	// which does exactly what this admission controller used to do. So once GCE and AWS can
+	// which does exactly what this admission controller used to do. So once GCE, AWS and AZURE can
 	// run externally, we can remove this admission controller.
 	glog.Warning("PersistentVolumeLabel admission controller is deprecated. " +
 		"Please remove this controller from your configuration files and scripts.")
@@ -123,6 +125,13 @@ func (l *persistentVolumeLabel) Admit(a admission.Attributes) (err error) {
 		}
 		volumeLabels = labels
 	}
+	if volume.Spec.AzureDisk != nil {
+		labels, err := l.findAzureDiskLabels(volume)
+		if err != nil {
+			return admission.NewForbidden(a, fmt.Errorf("error querying AzureDisk volume %s: %v", volume.Spec.AzureDisk.DiskName, err))
+		}
+		volumeLabels = labels
+	}
 
 	requirements := make([]api.NodeSelectorRequirement, 0)
 	if len(volumeLabels) != 0 {
@@ -272,3 +281,45 @@ func (l *persistentVolumeLabel) getGCECloudProvider() (*gce.GCECloud, error) {
 	}
 	return l.gceCloudProvider, nil
 }
+
+// getAzureCloudProvider returns the Azure cloud provider, for use for querying volume labels
+func (l *persistentVolumeLabel) getAzureCloudProvider() (*azure.Cloud, error) {
+	l.mutex.Lock()
+	defer l.mutex.Unlock()
+
+	if l.azureProvider == nil {
+		var cloudConfigReader io.Reader
+		if len(l.cloudConfig) > 0 {
+			cloudConfigReader = bytes.NewReader(l.cloudConfig)
+		}
+		cloudProvider, err := cloudprovider.GetCloudProvider("azure", cloudConfigReader)
+		if err != nil || cloudProvider == nil {
+			return nil, err
+		}
+		azureProvider, ok := cloudProvider.(*azure.Cloud)
+		if !ok {
+			// GetCloudProvider has gone very wrong
+			return nil, fmt.Errorf("error retrieving Azure cloud provider")
+		}
+		l.azureProvider = azureProvider
+	}
+
+	return l.azureProvider, nil
+}
+
+func (l *persistentVolumeLabel) findAzureDiskLabels(volume *api.PersistentVolume) (map[string]string, error) {
+	// Ignore any volumes that are being provisioned
+	if volume.Spec.AzureDisk.DiskName == vol.ProvisionedVolumeName {
+		return nil, nil
+	}
+
+	provider, err := l.getAzureCloudProvider()
+	if err != nil {
+		return nil, err
+	}
+	if provider == nil {
+		return nil, fmt.Errorf("unable to build Azure cloud provider for AzureDisk")
+	}
+
+	return provider.GetAzureDiskLabels(volume.Spec.AzureDisk.DataDiskURI)
+}