Chose availability zones from active nodes

pkg/cloudprovider/providers/azure/azure.go

@@ -21,13 +21,19 @@ import (
 	"io"
 	"io/ioutil"
 	"strings"
+	"sync"
 	"time"
 
+	"k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/util/sets"
 	"k8s.io/apimachinery/pkg/util/wait"
+	"k8s.io/client-go/informers"
+	"k8s.io/client-go/tools/cache"
 	"k8s.io/client-go/util/flowcontrol"
 	"k8s.io/kubernetes/pkg/cloudprovider"
 	"k8s.io/kubernetes/pkg/cloudprovider/providers/azure/auth"
 	"k8s.io/kubernetes/pkg/controller"
+	kubeletapis "k8s.io/kubernetes/pkg/kubelet/apis"
 	"k8s.io/kubernetes/pkg/version"
 
 	"github.com/Azure/go-autorest/autorest"
@@ -150,6 +156,13 @@ type Cloud struct {
 	metadata                *InstanceMetadata
 	vmSet                   VMSet
 
+	// Lock for access to nodeZones
+	nodeZonesLock sync.Mutex
+	// nodeZones is a mapping from Zone to a sets.String of Node's names in the Zone
+	// it is updated by the nodeInformer
+	nodeZones          map[string]sets.String
+	nodeInformerSynced cache.InformerSynced
+
 	// Clients for vmss.
 	VirtualMachineScaleSetsClient   VirtualMachineScaleSetsClient
 	VirtualMachineScaleSetVMsClient VirtualMachineScaleSetVMsClient
@@ -243,6 +256,7 @@ func NewCloud(configReader io.Reader) (cloudprovider.Interface, error) {
 	az := Cloud{
 		Config:      *config,
 		Environment: *env,
+		nodeZones:   map[string]sets.String{},
 
 		DisksClient:                     newAzDisksClient(azClientConfig),
 		RoutesClient:                    newAzRoutesClient(azClientConfig),
@@ -427,3 +441,87 @@ func initDiskControllers(az *Cloud) error {
 
 	return nil
 }
+
+// SetInformers sets informers for Azure cloud provider.
+func (az *Cloud) SetInformers(informerFactory informers.SharedInformerFactory) {
+	glog.Infof("Setting up informers for Azure cloud provider")
+	nodeInformer := informerFactory.Core().V1().Nodes().Informer()
+	nodeInformer.AddEventHandler(cache.ResourceEventHandlerFuncs{
+		AddFunc: func(obj interface{}) {
+			node := obj.(*v1.Node)
+			az.updateNodeZones(nil, node)
+		},
+		UpdateFunc: func(prev, obj interface{}) {
+			prevNode := prev.(*v1.Node)
+			newNode := obj.(*v1.Node)
+			if newNode.Labels[kubeletapis.LabelZoneFailureDomain] ==
+				prevNode.Labels[kubeletapis.LabelZoneFailureDomain] {
+				return
+			}
+			az.updateNodeZones(prevNode, newNode)
+		},
+		DeleteFunc: func(obj interface{}) {
+			node, isNode := obj.(*v1.Node)
+			// We can get DeletedFinalStateUnknown instead of *v1.Node here
+			// and we need to handle that correctly.
+			if !isNode {
+				deletedState, ok := obj.(cache.DeletedFinalStateUnknown)
+				if !ok {
+					glog.Errorf("Received unexpected object: %v", obj)
+					return
+				}
+				node, ok = deletedState.Obj.(*v1.Node)
+				if !ok {
+					glog.Errorf("DeletedFinalStateUnknown contained non-Node object: %v", deletedState.Obj)
+					return
+				}
+			}
+			az.updateNodeZones(node, nil)
+		},
+	})
+	az.nodeInformerSynced = nodeInformer.HasSynced
+}
+
+func (az *Cloud) updateNodeZones(prevNode, newNode *v1.Node) {
+	az.nodeZonesLock.Lock()
+	defer az.nodeZonesLock.Unlock()
+	if prevNode != nil {
+		prevZone, ok := prevNode.ObjectMeta.Labels[kubeletapis.LabelZoneFailureDomain]
+		if ok && az.isAvailabilityZone(prevZone) {
+			az.nodeZones[prevZone].Delete(prevNode.ObjectMeta.Name)
+			if az.nodeZones[prevZone].Len() == 0 {
+				az.nodeZones[prevZone] = nil
+			}
+		}
+	}
+	if newNode != nil {
+		newZone, ok := newNode.ObjectMeta.Labels[kubeletapis.LabelZoneFailureDomain]
+		if ok && az.isAvailabilityZone(newZone) {
+			if az.nodeZones[newZone] == nil {
+				az.nodeZones[newZone] = sets.NewString()
+			}
+			az.nodeZones[newZone].Insert(newNode.ObjectMeta.Name)
+		}
+	}
+}
+
+// GetActiveZones returns all the zones in which k8s nodes are currently running.
+func (az *Cloud) GetActiveZones() (sets.String, error) {
+	if az.nodeInformerSynced == nil {
+		return nil, fmt.Errorf("Azure cloud provider doesn't have informers set")
+	}
+
+	az.nodeZonesLock.Lock()
+	defer az.nodeZonesLock.Unlock()
+	if !az.nodeInformerSynced() {
+		return nil, fmt.Errorf("node informer is not synced when trying to GetActiveZones")
+	}
+
+	zones := sets.NewString()
+	for zone, nodes := range az.nodeZones {
+		if len(nodes) > 0 {
+			zones.Insert(zone)
+		}
+	}
+	return zones, nil
+}

pkg/cloudprovider/providers/azure/azure_managedDiskController.go

@@ -29,6 +29,7 @@ import (
 
 	"k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/api/resource"
+	"k8s.io/apimachinery/pkg/util/sets"
 	kwait "k8s.io/apimachinery/pkg/util/wait"
 	kubeletapis "k8s.io/kubernetes/pkg/kubelet/apis"
 	"k8s.io/kubernetes/pkg/volume"
@@ -61,26 +62,33 @@ func newManagedDiskController(common *controllerCommon) (*ManagedDiskController,
 
 //CreateManagedDisk : create managed disk
 func (c *ManagedDiskController) CreateManagedDisk(options *ManagedDiskOptions) (string, error) {
+	var zones sets.String
+	var activeZones sets.String
+	var err error
 	glog.V(4).Infof("azureDisk - creating new managed Name:%s StorageAccountType:%s Size:%v", options.DiskName, options.StorageAccountType, options.SizeGB)
 
+	// Get active zones which have nodes running on.
+	activeZones, err = c.common.cloud.GetActiveZones()
+	if err != nil {
+		return "", fmt.Errorf("error querying active zones: %v", err)
+	}
+
 	// Validate and choose availability zone for creating disk.
-	var createAZ string
 	if options.Zoned && !options.ZonePresent && !options.ZonesPresent {
-		// TODO: get zones from active zones that with running nodes.
+		// Neither "zone" or "zones" specified. Pick a zone randomly selected
-	}
+		// from all active zones where Kubernetes cluster has a node.
-	if !options.ZonePresent && options.ZonesPresent {
+		zones = activeZones
+	} else if !options.ZonePresent && options.ZonesPresent {
 		// Choose zone from specified zones.
-		if adminSetOfZones, err := util.ZonesToSet(options.AvailabilityZones); err != nil {
+		if zones, err = util.ZonesToSet(options.AvailabilityZones); err != nil {
 			return "", err
-		} else {
-			createAZ = util.ChooseZoneForVolume(adminSetOfZones, options.PVCName)
 		}
-	}
+	} else if options.ZonePresent && !options.ZonesPresent {
-	if options.ZonePresent && !options.ZonesPresent {
 		if err := util.ValidateZone(options.AvailabilityZone); err != nil {
 			return "", err
 		}
-		createAZ = options.AvailabilityZone
+		zones = make(sets.String)
+		zones.Insert(options.AvailabilityZone)
 	}
 
 	// insert original tags to newTags
@@ -112,14 +120,21 @@ func (c *ManagedDiskController) CreateManagedDisk(options *ManagedDiskOptions) (
 	if options.ResourceGroup == "" {
 		options.ResourceGroup = c.common.resourceGroup
 	}
-	if createAZ != "" {
+	if len(zones.List()) > 0 {
-		createZones := []string{createAZ}
+		createAZ := util.ChooseZoneForVolume(zones, options.PVCName)
+		// Do not allow creation of disks in zones that are do not have nodes. Such disks
+		// are not currently usable.
+		if !activeZones.Has(createAZ) {
+			return "", fmt.Errorf("kubernetes does not have a node in zone %q", createAZ)
+		}
+
+		createZones := []string{c.common.cloud.GetZoneID(createAZ)}
 		model.Zones = &createZones
 	}
 
 	ctx, cancel := getContextWithCancel()
 	defer cancel()
-	_, err := c.common.cloud.DisksClient.CreateOrUpdate(ctx, options.ResourceGroup, options.DiskName, model)
+	_, err = c.common.cloud.DisksClient.CreateOrUpdate(ctx, options.ResourceGroup, options.DiskName, model)
 	if err != nil {
 		return "", err
 	}