Merge pull request kubernetes#89138 from feiskyer/vmss-fix

Fix isCurrentInstance for Windows by removing the dependency of hostname

Author: k8s-ci-robot

staging/src/k8s.io/legacy-cloud-providers/azure/azure_instances.go

@@ -21,7 +21,7 @@ package azure
 import (
 	"context"
 	"fmt"
-	"os"
+	"strconv"
 	"strings"
 
 	v1 "k8s.io/api/core/v1"
@@ -231,18 +231,22 @@ func (az *Cloud) InstanceShutdownByProviderID(ctx context.Context, providerID st
 }
 
 func (az *Cloud) isCurrentInstance(name types.NodeName, metadataVMName string) (bool, error) {
-	var err error
 	nodeName := mapNodeNameToVMName(name)
+
 	if az.VMType == vmTypeVMSS {
-		// VMSS vmName is not same with hostname, use hostname instead.
-		metadataVMName, err = os.Hostname()
-		if err != nil {
-			return false, err
+		// VMSS vmName is not same with hostname, construct the node name "{computer-name-prefix}{base-36-instance-id}".
+		// Refer https://docs.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-instance-ids#scale-set-vm-computer-name.
+		if ssName, instanceID, err := extractVmssVMName(metadataVMName); err == nil {
+			instance, err := strconv.ParseInt(instanceID, 10, 64)
+			if err != nil {
+				return false, fmt.Errorf("failed to parse VMSS instanceID %q: %v", instanceID, err)
+			}
+			metadataVMName = fmt.Sprintf("%s%06s", ssName, strconv.FormatInt(instance, 36))
 		}
 	}
 
 	metadataVMName = strings.ToLower(metadataVMName)
-	return (metadataVMName == nodeName), err
+	return (metadataVMName == nodeName), nil
 }
 
 // InstanceID returns the cloud provider ID of the specified instance.

staging/src/k8s.io/legacy-cloud-providers/azure/azure_instances_test.go

@@ -361,3 +361,56 @@ func TestNodeAddresses(t *testing.T) {
 		}
 	}
 }
+
+func TestIsCurrentInstance(t *testing.T) {
+	cloud := &Cloud{
+		Config: Config{
+			VMType: vmTypeVMSS,
+		},
+	}
+	testcases := []struct {
+		nodeName       string
+		metadataVMName string
+		expected       bool
+		expectError    bool
+	}{
+		{
+			nodeName:       "node1",
+			metadataVMName: "node1",
+			expected:       true,
+		},
+		{
+			nodeName:       "node1",
+			metadataVMName: "node2",
+			expected:       false,
+		},
+		{
+			nodeName:       "vmss000001",
+			metadataVMName: "vmss_1",
+			expected:       true,
+		},
+		{
+			nodeName:       "vmss_2",
+			metadataVMName: "vmss000000",
+			expected:       false,
+		},
+		{
+			nodeName:       "vmss123456",
+			metadataVMName: "vmss_$123",
+			expected:       false,
+			expectError:    true,
+		},
+	}
+
+	for i, test := range testcases {
+		real, err := cloud.isCurrentInstance(types.NodeName(test.nodeName), test.metadataVMName)
+		if test.expectError {
+			if err == nil {
+				t.Errorf("Test[%d] unexpected nil err", i)
+			}
+		}
+		if real != test.expected {
+			t.Errorf("Test[%d] unexpected isCurrentInstance result %v != %v", i, real, test.expected)
+		}
+	}
+}