Convert resource group name in Azure provider ID to lower cases

pkg/cloudprovider/providers/azure/azure.go

@@ -423,6 +423,9 @@ func parseConfig(configReader io.Reader) (*Config, error) {
 		return nil, err
 	}
 
+	// The resource group name may be in different cases from different Azure APIs, hence it is converted to lower here.
+	// See more context at https://github.com/kubernetes/kubernetes/issues/71994.
+	config.ResourceGroup = strings.ToLower(config.ResourceGroup)
 	return &config, nil
 }
 
@@ -578,7 +581,7 @@ func (az *Cloud) updateNodeCaches(prevNode, newNode *v1.Node) {
 		// Add to nodeResourceGroups cache.
 		newRG, ok := newNode.ObjectMeta.Labels[externalResourceGroupLabel]
 		if ok && len(newRG) > 0 {
-			az.nodeResourceGroups[newNode.ObjectMeta.Name] = newRG
+			az.nodeResourceGroups[newNode.ObjectMeta.Name] = strings.ToLower(newRG)
 		}
 
 		// Add to unmanagedNodes cache.
@@ -677,7 +680,7 @@ func (az *Cloud) GetUnmanagedNodes() (sets.String, error) {
 // ShouldNodeExcludedFromLoadBalancer returns true if node is unmanaged or in external resource group.
 func (az *Cloud) ShouldNodeExcludedFromLoadBalancer(node *v1.Node) bool {
 	labels := node.ObjectMeta.Labels
-	if rg, ok := labels[externalResourceGroupLabel]; ok && rg != az.ResourceGroup {
+	if rg, ok := labels[externalResourceGroupLabel]; ok && !strings.EqualFold(rg, az.ResourceGroup) {
 		return true
 	}
 

pkg/cloudprovider/providers/azure/azure_instances.go

@@ -246,7 +246,7 @@ func (az *Cloud) InstanceID(ctx context.Context, name types.NodeName) (string, e
 		}
 
 		// Get resource group name.
-		resourceGroup := metadata.Compute.ResourceGroup
+		resourceGroup := strings.ToLower(metadata.Compute.ResourceGroup)
 
 		// Compose instanceID based on nodeName for standard instance.
 		if az.VMType == vmTypeStandard {

pkg/cloudprovider/providers/azure/azure_metrics.go

@@ -17,6 +17,7 @@ limitations under the License.
 package azure
 
 import (
+	"strings"
 	"time"
 
 	"github.com/prometheus/client_golang/prometheus"
@@ -45,7 +46,7 @@ type metricContext struct {
 func newMetricContext(prefix, request, resourceGroup, subscriptionID string) *metricContext {
 	return &metricContext{
 		start:      time.Now(),
-		attributes: []string{prefix + "_" + request, resourceGroup, subscriptionID},
+		attributes: []string{prefix + "_" + request, strings.ToLower(resourceGroup), subscriptionID},
 	}
 }
 

pkg/cloudprovider/providers/azure/azure_standard.go

@@ -70,7 +70,7 @@ func (az *Cloud) getStandardMachineID(resourceGroup, machineName string) string
 	return fmt.Sprintf(
 		machineIDTemplate,
 		az.SubscriptionID,
-		resourceGroup,
+		strings.ToLower(resourceGroup),
 		machineName)
 }
 
@@ -339,7 +339,14 @@ func (as *availabilitySet) GetInstanceIDByNodeName(name string) (string, error)
 			return "", err
 		}
 	}
-	return *machine.ID, nil
+
+	resourceID := *machine.ID
+	convertedResourceID, err := convertResourceGroupNameToLower(resourceID)
+	if err != nil {
+		klog.Errorf("convertResourceGroupNameToLower failed with error: %v", err)
+		return "", err
+	}
+	return convertedResourceID, nil
 }
 
 // GetPowerStatusByNodeName returns the power state of the specified node.

pkg/cloudprovider/providers/azure/azure_test.go

@@ -99,7 +99,7 @@ func TestParseConfig(t *testing.T) {
 		MaximumLoadBalancerRuleCount:      1,
 		PrimaryAvailabilitySetName:        "primaryAvailabilitySetName",
 		PrimaryScaleSetName:               "primaryScaleSetName",
-		ResourceGroup:                     "resourceGroup",
+		ResourceGroup:                     "resourcegroup",
 		RouteTableName:                    "routeTableName",
 		SecurityGroupName:                 "securityGroupName",
 		SubnetName:                        "subnetName",

pkg/cloudprovider/providers/azure/azure_vmss.go

@@ -185,7 +185,13 @@ func (ss *scaleSet) GetInstanceIDByNodeName(name string) (string, error) {
 		return "", err
 	}
 
-	return *vm.ID, nil
+	resourceID := *vm.ID
+	convertedResourceID, err := convertResourceGroupNameToLower(resourceID)
+	if err != nil {
+		klog.Errorf("convertResourceGroupNameToLower failed with error: %v", err)
+		return "", err
+	}
+	return convertedResourceID, nil
 }
 
 // GetNodeNameByProviderID gets the node name by provider ID.
@@ -980,7 +986,7 @@ func (az *Cloud) getVmssMachineID(resourceGroup, scaleSetName, instanceID string
 	return fmt.Sprintf(
 		vmssMachineIDTemplate,
 		az.SubscriptionID,
-		resourceGroup,
+		strings.ToLower(resourceGroup),
 		scaleSetName,
 		instanceID)
 }

pkg/cloudprovider/providers/azure/azure_vmss_cache.go

@@ -152,7 +152,7 @@ func (ss *scaleSet) newAvailabilitySetNodesCache() (*timedCache, error) {
 
 func buildVmssCacheKey(resourceGroup, name string) string {
 	// key is composed of <resourceGroup>#<vmName>
-	return fmt.Sprintf("%s%s%s", resourceGroup, vmssCacheSeparator, name)
+	return fmt.Sprintf("%s%s%s", strings.ToLower(resourceGroup), vmssCacheSeparator, name)
 }
 
 func extractVmssCacheKey(key string) (string, string, error) {

pkg/cloudprovider/providers/azure/azure_wrap.go

@@ -37,7 +37,8 @@ var (
 	nsgCacheTTL = 2 * time.Minute
 	rtCacheTTL  = 2 * time.Minute
 
-	azureNodeProviderIDRE = regexp.MustCompile(`^azure:///subscriptions/(?:.*)/resourceGroups/(?:.*)/providers/Microsoft.Compute/(?:.*)`)
+	azureNodeProviderIDRE    = regexp.MustCompile(`^azure:///subscriptions/(?:.*)/resourceGroups/(?:.*)/providers/Microsoft.Compute/(?:.*)`)
+	azureResourceGroupNameRE = regexp.MustCompile(`.*/subscriptions/(?:.*)/resourceGroups/(.+)/providers/(?:.*)`)
 )
 
 // checkExistsFromError inspects an error and returns a true if err is nil,
@@ -303,3 +304,14 @@ func (az *Cloud) IsNodeUnmanaged(nodeName string) (bool, error) {
 func (az *Cloud) IsNodeUnmanagedByProviderID(providerID string) bool {
 	return !azureNodeProviderIDRE.Match([]byte(providerID))
 }
+
+// convertResourceGroupNameToLower converts the resource group name in the resource ID to be lowered.
+func convertResourceGroupNameToLower(resourceID string) (string, error) {
+	matches := azureResourceGroupNameRE.FindStringSubmatch(resourceID)
+	if len(matches) != 2 {
+		return "", fmt.Errorf("%q isn't in Azure resource ID format %q", resourceID, azureResourceGroupNameRE.String())
+	}
+
+	resourceGroup := matches[1]
+	return strings.Replace(resourceID, resourceGroup, strings.ToLower(resourceGroup), 1), nil
+}

pkg/cloudprovider/providers/azure/azure_wrap_test.go

@@ -142,3 +142,59 @@ func TestIsNodeUnmanagedByProviderID(t *testing.T) {
 		assert.Equal(t, test.expected, isUnmanagedNode, test.providerID)
 	}
 }
+
+func TestConvertResourceGroupNameToLower(t *testing.T) {
+	tests := []struct {
+		desc        string
+		resourceID  string
+		expected    string
+		expectError bool
+	}{
+		{
+			desc:        "empty string should report error",
+			resourceID:  "",
+			expectError: true,
+		},
+		{
+			desc:        "resourceID not in Azure format should report error",
+			resourceID:  "invalid-id",
+			expectError: true,
+		},
+		{
+			desc:        "providerID not in Azure format should report error",
+			resourceID:  "azure://invalid-id",
+			expectError: true,
+		},
+		{
+			desc:       "resource group name in VM providerID should be converted",
+			resourceID: CloudProviderName + ":///subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/myResourceGroupName/providers/Microsoft.Compute/virtualMachines/k8s-agent-AAAAAAAA-0",
+			expected:   CloudProviderName + ":///subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/myresourcegroupname/providers/Microsoft.Compute/virtualMachines/k8s-agent-AAAAAAAA-0",
+		},
+		{
+			desc:       "resource group name in VM resourceID should be converted",
+			resourceID: "/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/myResourceGroupName/providers/Microsoft.Compute/virtualMachines/k8s-agent-AAAAAAAA-0",
+			expected:   "/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/myresourcegroupname/providers/Microsoft.Compute/virtualMachines/k8s-agent-AAAAAAAA-0",
+		},
+		{
+			desc:       "resource group name in VMSS providerID should be converted",
+			resourceID: CloudProviderName + ":///subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/myResourceGroupName/providers/Microsoft.Compute/virtualMachineScaleSets/myScaleSetName/virtualMachines/156",
+			expected:   CloudProviderName + ":///subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/myresourcegroupname/providers/Microsoft.Compute/virtualMachineScaleSets/myScaleSetName/virtualMachines/156",
+		},
+		{
+			desc:       "resource group name in VMSS resourceID should be converted",
+			resourceID: "/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/myResourceGroupName/providers/Microsoft.Compute/virtualMachineScaleSets/myScaleSetName/virtualMachines/156",
+			expected:   "/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/myresourcegroupname/providers/Microsoft.Compute/virtualMachineScaleSets/myScaleSetName/virtualMachines/156",
+		},
+	}
+
+	for _, test := range tests {
+		real, err := convertResourceGroupNameToLower(test.resourceID)
+		if test.expectError {
+			assert.NotNil(t, err, test.desc)
+			continue
+		}
+
+		assert.Nil(t, err, test.desc)
+		assert.Equal(t, test.expected, real, test.desc)
+	}
+}