cleanup implementation

Author: alimaazamat

cluster-autoscaler/cloudprovider/azure/azure_config.go

@@ -115,6 +115,16 @@ type Config struct {
 
 	// EnableLabelPredictionsOnTemplate defines whether to enable label predictions on the template when scaling from zero
 	EnableLabelPredictionsOnTemplate bool `json:"enableLabelPredictionsOnTemplate,omitempty" yaml:"enableLabelPredictionsOnTemplate,omitempty"`
+
+	// EnableZombieCleanup defines whether to enable automatic cleanup of zombie VMSS instances
+	EnableZombieCleanup bool `json:"enableZombieCleanup,omitempty" yaml:"enableZombieCleanup,omitempty"`
+
+	// ZombieCleanupDryRun defines whether zombie cleanup should run in dry-run mode (detect but don't delete)
+	// In dry-run mode, zombies are detected and logged but NOT deleted
+	ZombieCleanupDryRun bool `json:"zombieCleanupDryRun,omitempty" yaml:"zombieCleanupDryRun,omitempty"`
+
+	// ZombieMinAgeMinutes defines the minimum age (in minutes) before an instance is considered a zombie
+	ZombieMinAgeMinutes int `json:"zombieMinAgeMinutes,omitempty" yaml:"zombieMinAgeMinutes,omitempty"`
 }
 
 // These are only here for backward compabitility. Their equivalent exists in providerazure.Config with a different name.
@@ -146,6 +156,10 @@ func BuildAzureConfig(configReader io.Reader) (*Config, error) {
 	cfg.MaxDeploymentsCount = int64(defaultMaxDeploymentsCount)
 	cfg.StrictCacheUpdates = false
 	cfg.EnableLabelPredictionsOnTemplate = true
+	// Zombie cleanup disabled by default for safety
+	cfg.EnableZombieCleanup = false
+	cfg.ZombieCleanupDryRun = true // Default to dry-run mode for extra safety
+	cfg.ZombieMinAgeMinutes = 5    // Default 5 minutes minimum age
 
 	// Config file overrides defaults
 	if configReader != nil {

cluster-autoscaler/cloudprovider/azure/azure_manager.go

@@ -232,6 +232,12 @@ func (m *AzureManager) forceRefresh() error {
 	}
 	m.lastRefresh = time.Now()
 	klog.V(2).Infof("Refreshed Azure VM and VMSS list, next refresh after %v", m.lastRefresh.Add(m.azureCache.refreshInterval))
+
+	if err := m.cleanupZombieNodes(); err != nil {
+		klog.Errorf("Failed to cleanup zombie nodes: %v", err)
+		// Don't fail the refresh if zombie cleanup fails
+	}
+
 	return nil
 }