fix: support non-zonal regions (#35)

pkg/cloudprovider/cloudprovider.go

@@ -360,5 +360,8 @@ func GenerateNodeClaimName(vmName string) string {
 
 // makeZone returns the zone value in format of <region>-<zone-id>.
 func makeZone(location string, zoneID string) string {
+	if zoneID == "" {
+		return ""
+	}
 	return fmt.Sprintf("%s-%s", strings.ToLower(location), zoneID)
 }

pkg/controllers/nodeclaim/garbagecollection/suite_test.go

@@ -30,6 +30,7 @@ import (
 	"github.com/Azure/karpenter/pkg/cloudprovider"
 	"github.com/Azure/karpenter/pkg/controllers/nodeclaim/garbagecollection"
 	link "github.com/Azure/karpenter/pkg/controllers/nodeclaim/link"
+	"github.com/Azure/karpenter/pkg/fake"
 	"github.com/Azure/karpenter/pkg/providers/instance"
 	"github.com/Azure/karpenter/pkg/utils"
 	. "github.com/onsi/ginkgo/v2"
@@ -126,8 +127,9 @@ var _ = Describe("NodeClaimGarbageCollection", func() {
 	BeforeEach(func() {
 		id := utils.MkVMID(azureEnv.AzureResourceGraphAPI.ResourceGroup, "vm-a")
 		vm = armcompute.VirtualMachine{
-			ID:   lo.ToPtr(id),
-			Name: lo.ToPtr("vm-a"),
+			ID:       lo.ToPtr(id),
+			Name:     lo.ToPtr("vm-a"),
+			Location: lo.ToPtr(fake.Region),
 			Tags: map[string]*string{
 				instance.NodePoolTagKey: lo.ToPtr("default"),
 			},
@@ -191,8 +193,9 @@ var _ = Describe("NodeClaimGarbageCollection", func() {
 			azureEnv.VirtualMachinesAPI.Instances.Store(
 				vmID,
 				armcompute.VirtualMachine{
-					ID:   lo.ToPtr(utils.MkVMID(azureEnv.AzureResourceGraphAPI.ResourceGroup, vmName)),
-					Name: lo.ToPtr(vmName),
+					ID:       lo.ToPtr(utils.MkVMID(azureEnv.AzureResourceGraphAPI.ResourceGroup, vmName)),
+					Name:     lo.ToPtr(vmName),
+					Location: lo.ToPtr(fake.Region),
 					Properties: &armcompute.VirtualMachineProperties{
 						TimeCreated: lo.ToPtr(time.Now().Add(-time.Minute * 10)),
 					},
@@ -230,8 +233,9 @@ var _ = Describe("NodeClaimGarbageCollection", func() {
 			azureEnv.VirtualMachinesAPI.Instances.Store(
 				vmID,
 				armcompute.VirtualMachine{
-					ID:   lo.ToPtr(utils.MkVMID(azureEnv.AzureResourceGraphAPI.ResourceGroup, vmName)),
-					Name: lo.ToPtr(vmName),
+					ID:       lo.ToPtr(utils.MkVMID(azureEnv.AzureResourceGraphAPI.ResourceGroup, vmName)),
+					Name:     lo.ToPtr(vmName),
+					Location: lo.ToPtr(fake.Region),
 					Properties: &armcompute.VirtualMachineProperties{
 						TimeCreated: lo.ToPtr(time.Now().Add(-time.Minute * 10)),
 					},

pkg/providers/instance/instance.go

@@ -353,7 +353,7 @@ func newVMObject(
 				CapacityTypeToPriority[capacityType]),
 			),
 		},
-		Zones: []*string{&zone},
+		Zones: lo.Ternary(len(zone) > 0, []*string{&zone}, []*string{}),
 		Tags:  launchTemplate.Tags,
 	}
 	setVMPropertiesStorageProfile(vm.Properties, instanceType, nodeClass)
@@ -560,9 +560,11 @@ func (p *Provider) pickSkuSizePriorityAndZone(ctx context.Context, nodeClaim *co
 	})
 	zonesWithPriority := lo.Map(priorityOfferings, func(o corecloudprovider.Offering, _ int) string { return o.Zone })
 	if zone, ok := sets.New(zonesWithPriority...).PopAny(); ok {
-		// Zones in Offerings have <region>-<number> format; the zone returned from here will be used for VM instantiation,
-		// which expects just the zone number, without region
-		zone = string(zone[len(zone)-1])
+		if len(zone) > 0 {
+			// Zones in zonal Offerings have <region>-<number> format; the zone returned from here will be used for VM instantiation,
+			// which expects just the zone number, without region
+			zone = string(zone[len(zone)-1])
+		}
 		return instanceType, priority, zone
 	}
 	return nil, "", ""
@@ -637,6 +639,7 @@ func (p *Provider) getAKSIdentifyingExtension() *armcompute.VirtualMachineExtens
 	return vmExtension
 }
 
+// GetZoneID returns the zone ID for the given virtual machine, or an empty string if there is no zone specified
 func GetZoneID(vm *armcompute.VirtualMachine) (string, error) {
 	if vm == nil {
 		return "", fmt.Errorf("cannot pass in a nil virtual machine")
@@ -645,15 +648,15 @@ func GetZoneID(vm *armcompute.VirtualMachine) (string, error) {
 		return "", fmt.Errorf("virtual machine is missing name")
 	}
 	if vm.Zones == nil {
-		return "", fmt.Errorf("virtual machine %v zones are nil", *vm.Name)
+		return "", nil
 	}
 	if len(vm.Zones) == 1 {
 		return *(vm.Zones)[0], nil
 	}
 	if len(vm.Zones) > 1 {
 		return "", fmt.Errorf("virtual machine %v has multiple zones", *vm.Name)
 	}
-	return "", fmt.Errorf("virtual machine %v does not have any zones specified", *vm.Name)
+	return "", nil
 }
 
 func GetListQueryBuilder(rg string) *kql.Builder {

pkg/providers/instancetype/instancetypes.go

@@ -117,9 +117,13 @@ func instanceTypeZones(sku *skewer.SKU, region string) sets.Set[string] {
 	// skewer returns numerical zones, like "1" (as keys in the map);
 	// prefix each zone with "<region>-", to have them match the labels placed on Node (e.g. "westus2-1")
 	// Note this data comes from LocationInfo, then skewer is used to get the SKU info
-	return sets.New(lo.Map(lo.Keys(sku.AvailabilityZones(region)), func(zone string, _ int) string {
-		return fmt.Sprintf("%s-%s", region, zone)
-	})...)
+	if hasZonalSupport(region) {
+		return sets.New(lo.Map(lo.Keys(sku.AvailabilityZones(region)), func(zone string, _ int) string {
+			return fmt.Sprintf("%s-%s", region, zone)
+		})...)
+	}
+
+	return sets.New("") // empty string means non-zonal offering
 }
 
 func (p *Provider) createOfferings(sku *skewer.SKU, zones sets.Set[string]) []cloudprovider.Offering {
@@ -156,7 +160,7 @@ func (p *Provider) getInstanceTypes(ctx context.Context) (map[string]*skewer.SKU
 			continue
 		}
 
-		if p.isSupported(&skus[i], vmsize) {
+		if !skus[i].HasLocationRestriction(p.region) && p.isSupported(&skus[i], vmsize) {
 			instanceTypes[skus[i].GetName()] = &skus[i]
 		}
 	}
@@ -233,3 +237,49 @@ func MaxEphemeralOSDiskSizeGB(sku *skewer.SKU) float64 {
 	// convert bytes to GB
 	return maxDiskBytes / float64(units.Gigabyte)
 }
+
+var (
+	// https://learn.microsoft.com/en-us/azure/reliability/availability-zones-service-support#azure-regions-with-availability-zone-support
+	// (could also be obtained programmatically)
+	zonalRegions = sets.New(
+		// Americas
+		"brazilsouth",
+		"canadacentral",
+		"centralus",
+		"eastus",
+		"eastus2",
+		"southcentralus",
+		"usgovvirginia",
+		"westus2",
+		"westus3",
+		// Europe
+		"francecentral",
+		"italynorth",
+		"germanywestcentral",
+		"norwayeast",
+		"northeurope",
+		"uksouth",
+		"westeurope",
+		"swedencentral",
+		"switzerlandnorth",
+		"polandcentral",
+		// Middle East
+		"qatarcentral",
+		"uaenorth",
+		"israelcentral",
+		// Africa
+		"southafricanorth",
+		// Asia Pacific
+		"australiaeast",
+		"centralindia",
+		"japaneast",
+		"koreacentral",
+		"southeastasia",
+		"eastasia",
+		"chinanorth3",
+	)
+)
+
+func hasZonalSupport(region string) bool {
+	return zonalRegions.Has(region)
+}