azure: filter load balancer backend nodes to PrimaryAvailabilitySet if set

pkg/cloudprovider/providers/azure/azure.go

@@ -42,6 +42,7 @@ type Config struct {
 	SubnetName                 string `json:"subnetName" yaml:"subnetName"`
 	SecurityGroupName          string `json:"securityGroupName" yaml:"securityGroupName"`
 	RouteTableName             string `json:"routeTableName" yaml:"routeTableName"`
+	PrimaryAvailabilitySetName string `json:"primaryAvailabilitySetName" yaml:"primaryAvailabilitySetName"`
 
 	AADClientID     string `json:"aadClientId" yaml:"aadClientId"`
 	AADClientSecret string `json:"aadClientSecret" yaml:"aadClientSecret"`

pkg/cloudprovider/providers/azure/azure_loadbalancer.go

@@ -573,6 +573,17 @@ func (az *Cloud) ensureHostInPool(serviceName string, nodeName types.NodeName, b
 		return err
 	}
 
+	// Check availability set
+	if az.PrimaryAvailabilitySetName != "" {
+		expectedAvailabilitySetName := az.getAvailabilitySetID(az.PrimaryAvailabilitySetName)
+		if !strings.EqualFold(*machine.Properties.AvailabilitySet.ID, expectedAvailabilitySetName) {
+			glog.V(1).Infof(
+				"nicupdate(%s): skipping nic (%s) since it is not in the primaryAvailabilitSet(%s)",
+				serviceName, nicName, az.PrimaryAvailabilitySetName)
+			return nil
+		}
+	}
+
 	nic, err := az.InterfacesClient.Get(az.ResourceGroup, nicName, "")
 	if err != nil {
 		return err

pkg/cloudprovider/providers/azure/azure_test.go

@@ -412,7 +412,8 @@ func TestNewCloudFromJSON(t *testing.T) {
 		"subnetName": "--subnet-name--",
 		"securityGroupName": "--security-group-name--",
 		"vnetName": "--vnet-name--",
-		"routeTableName": "--route-table-name--"
+		"routeTableName": "--route-table-name--",
+		"primaryAvailabilitySetName": "--primary-availability-set-name--"
 	}`
 	validateConfig(t, config)
 }
@@ -430,6 +431,7 @@ subnetName: --subnet-name--
 securityGroupName: --security-group-name--
 vnetName: --vnet-name--
 routeTableName: --route-table-name--
+primaryAvailabilitySetName: --primary-availability-set-name--
 `
 	validateConfig(t, config)
 }
@@ -476,6 +478,9 @@ func validateConfig(t *testing.T, config string) {
 	if azureCloud.RouteTableName != "--route-table-name--" {
 		t.Errorf("got incorrect value for RouteTableName")
 	}
+	if azureCloud.PrimaryAvailabilitySetName != "--primary-availability-set-name--" {
+		t.Errorf("got incorrect value for PrimaryAvailabilitySetName")
+	}
 }
 
 func TestDecodeInstanceInfo(t *testing.T) {

pkg/cloudprovider/providers/azure/azure_util.go

@@ -32,7 +32,8 @@ const (
 	loadBalancerMinimumPriority = 500
 	loadBalancerMaximumPriority = 4096
 
-	machineResourceIDTemplate   = "/subscriptions/%s/resourceGroups/%s/providers/Microsoft.Compute/virtualMachines/%s"
+	machineIDTemplate           = "/subscriptions/%s/resourceGroups/%s/providers/Microsoft.Compute/virtualMachines/%s"
+	availabilitySetIDTemplate   = "/subscriptions/%s/resourceGroups/%s/providers/Microsoft.Compute/availabilitySets/%s"
 	frontendIPConfigIDTemplate  = "/subscriptions/%s/resourceGroups/%s/providers/Microsoft.Network/loadBalancers/%s/frontendIPConfigurations/%s"
 	backendPoolIDTemplate       = "/subscriptions/%s/resourceGroups/%s/providers/Microsoft.Network/loadBalancers/%s/backendAddressPools/%s"
 	loadBalancerRuleIDTemplate  = "/subscriptions/%s/resourceGroups/%s/providers/Microsoft.Network/loadBalancers/%s/loadBalancingRules/%s"
@@ -43,12 +44,21 @@ const (
 // returns the full identifier of a machine
 func (az *Cloud) getMachineID(machineName string) string {
 	return fmt.Sprintf(
-		machineResourceIDTemplate,
+		machineIDTemplate,
 		az.SubscriptionID,
 		az.ResourceGroup,
 		machineName)
 }
 
+// returns the full identifier of an availabilitySet
+func (az *Cloud) getAvailabilitySetID(availabilitySetName string) string {
+	return fmt.Sprintf(
+		availabilitySetIDTemplate,
+		az.SubscriptionID,
+		az.ResourceGroup,
+		availabilitySetName)
+}
+
 // returns the full identifier of a loadbalancer frontendipconfiguration.
 func (az *Cloud) getFrontendIPConfigID(lbName, backendPoolName string) string {
 	return fmt.Sprintf(