fix: panic in cache conversion

pkg/provider/azure_standard.go

@@ -1240,12 +1240,11 @@ func (as *availabilitySet) getAvailabilitySetByNodeName(nodeName string, crt azc
 	if err != nil {
 		return nil, err
 	}
-	vmasList := cached.(*sync.Map)
-
-	if vmasList == nil {
+	if cached == nil {
 		klog.Warning("Couldn't get all vmas from cache")
 		return nil, nil
 	}
+	vmasList := cached.(*sync.Map)
 
 	var result *compute.AvailabilitySet
 	vmasList.Range(func(_, value interface{}) bool {

pkg/provider/azure_vmss.go

@@ -141,6 +141,9 @@ func (ss *ScaleSet) getVMSS(vmssName string, crt azcache.AzureCacheReadType) (*c
 		if err != nil {
 			return nil, err
 		}
+		if cached == nil {
+			return nil, nil
+		}
 
 		vmsses := cached.(*sync.Map)
 		if vmss, ok := vmsses.Load(vmssName); ok {
@@ -186,6 +189,9 @@ func (ss *ScaleSet) getVmssVMByNodeIdentity(node *nodeIdentity, crt azcache.Azur
 		if err != nil {
 			return nil, found, err
 		}
+		if cached == nil {
+			return nil, found, nil
+		}
 
 		virtualMachines := cached.(*sync.Map)
 		if entry, ok := virtualMachines.Load(nodeName); ok {
@@ -333,6 +339,9 @@ func (ss *ScaleSet) getVmssVMByInstanceID(resourceGroup, scaleSetName, instanceI
 		if err != nil {
 			return nil, false, err
 		}
+		if cached == nil {
+			return nil, false, nil
+		}
 
 		virtualMachines := cached.(*sync.Map)
 		virtualMachines.Range(func(key, value interface{}) bool {
@@ -791,6 +800,9 @@ func (ss *ScaleSet) getNodeIdentityByNodeName(nodeName string, crt azcache.Azure
 		if err != nil {
 			return nil, err
 		}
+		if cached == nil {
+			return nil, nil
+		}
 
 		vmsses := cached.(*sync.Map)
 		vmsses.Range(func(key, value interface{}) bool {
@@ -1690,6 +1702,9 @@ func (ss *ScaleSet) ensureBackendPoolDeletedFromVMSS(backendPoolID, vmSetName st
 			klog.Errorf("ensureBackendPoolDeletedFromVMSS: failed to get vmss uniform from cache: %v", err)
 			return err
 		}
+		if cachedUniform == nil {
+			return nil
+		}
 		vmssUniformMap := cachedUniform.(*sync.Map)
 
 		vmssUniformMap.Range(func(key, value interface{}) bool {
@@ -1710,6 +1725,9 @@ func (ss *ScaleSet) ensureBackendPoolDeletedFromVMSS(backendPoolID, vmSetName st
 			klog.Errorf("ensureBackendPoolDeletedFromVMSS: failed to get vmss flex from cache: %v", err)
 			return err
 		}
+		if cachedFlex == nil {
+			return nil
+		}
 		vmssFlexMap := cachedFlex.(*sync.Map)
 		vmssFlexMap.Range(func(key, value interface{}) bool {
 			vmssFlex := value.(*compute.VirtualMachineScaleSet)
@@ -1749,6 +1767,9 @@ func (ss *ScaleSet) ensureBackendPoolDeletedFromVmssUniform(backendPoolID, vmSet
 			klog.Errorf("ensureBackendPoolDeletedFromVMSS: failed to get vmss uniform from cache: %v", err)
 			return err
 		}
+		if cachedUniform == nil {
+			return nil
+		}
 
 		vmssUniformMap := cachedUniform.(*sync.Map)
 		var errorList []error

pkg/provider/azure_vmss_cache.go

@@ -329,6 +329,11 @@ func (ss *ScaleSet) updateCache(nodeName, resourceGroupName, vmssName, instanceI
 	vmCache, err := timedCache.Get(cacheKey, azcache.CacheReadTypeUnsafe)
 	if err != nil {
 		klog.Errorf("updateCache(%s, %s, %s) failed getting vmCache with error: %v", vmssName, resourceGroupName, nodeName, err)
+		return nil
+	}
+	if vmCache == nil {
+		klog.Errorf("updateCache(%s, %s, %s) failed getting nil vmCache", vmssName, resourceGroupName, nodeName)
+		return nil
 	}
 
 	virtualMachines := vmCache.(*sync.Map)

pkg/provider/azure_vmssflex.go

@@ -803,6 +803,9 @@ func (fs *FlexScaleSet) ensureBackendPoolDeletedFromVmssFlex(backendPoolID strin
 			klog.Errorf("ensureBackendPoolDeletedFromVmssFlex: failed to get vmss flex from cache: %v", err)
 			return err
 		}
+		if cached == nil {
+			return nil
+		}
 		vmssFlexes := cached.(*sync.Map)
 		vmssFlexes.Range(func(key, value interface{}) bool {
 			vmssFlex := value.(*compute.VirtualMachineScaleSet)

pkg/provider/azure_vmssflex_cache.go

@@ -140,6 +140,9 @@ func (fs *FlexScaleSet) getNodeNameByVMName(vmName string) (string, error) {
 		if err != nil {
 			return "", err
 		}
+		if cached == nil {
+			return "", nil
+		}
 		vmssFlexes := cached.(*sync.Map)
 
 		vmssFlexes.Range(func(key, value interface{}) bool {
@@ -181,6 +184,9 @@ func (fs *FlexScaleSet) getNodeVmssFlexID(nodeName string) (string, error) {
 		if err != nil {
 			return "", err
 		}
+		if cached == nil {
+			return "", nil
+		}
 		vmssFlexes := cached.(*sync.Map)
 
 		vmssFlexes.Range(func(key, value interface{}) bool {
@@ -218,7 +224,9 @@ func (fs *FlexScaleSet) getVmssFlexVM(nodeName string, crt azcache.AzureCacheRea
 	if err != nil {
 		return vm, err
 	}
-
+	if cached == nil {
+		return vm, nil
+	}
 	vmMap := cached.(*sync.Map)
 	cachedVM, ok := vmMap.Load(nodeName)
 	if !ok {
@@ -234,7 +242,9 @@ func (fs *FlexScaleSet) getVmssFlexByVmssFlexID(vmssFlexID string, crt azcache.A
 	if err != nil {
 		return nil, err
 	}
-
+	if cached == nil {
+		return nil, nil
+	}
 	vmssFlexes := cached.(*sync.Map)
 	if vmssFlex, ok := vmssFlexes.Load(vmssFlexID); ok {
 		result := vmssFlex.(*compute.VirtualMachineScaleSet)
@@ -246,7 +256,9 @@ func (fs *FlexScaleSet) getVmssFlexByVmssFlexID(vmssFlexID string, crt azcache.A
 	if err != nil {
 		return nil, err
 	}
-
+	if cached == nil {
+		return nil, nil
+	}
 	vmssFlexes = cached.(*sync.Map)
 	if vmssFlex, ok := vmssFlexes.Load(vmssFlexID); ok {
 		result := vmssFlex.(*compute.VirtualMachineScaleSet)
@@ -272,7 +284,9 @@ func (fs *FlexScaleSet) getVmssFlexIDByName(vmssFlexName string) (string, error)
 	if err != nil {
 		return "", err
 	}
-
+	if cached == nil {
+		return "", nil
+	}
 	var targetVmssFlexID string
 	vmssFlexes := cached.(*sync.Map)
 	vmssFlexes.Range(func(key, value interface{}) bool {
@@ -298,6 +312,9 @@ func (fs *FlexScaleSet) getVmssFlexByName(vmssFlexName string) (*compute.Virtual
 	if err != nil {
 		return nil, err
 	}
+	if cached == nil {
+		return nil, nil
+	}
 
 	var targetVmssFlex *compute.VirtualMachineScaleSet
 	vmssFlexes := cached.(*sync.Map)
@@ -330,7 +347,9 @@ func (fs *FlexScaleSet) DeleteCacheForNode(nodeName string) error {
 	if err != nil {
 		return err
 	}
-
+	if cached == nil {
+		return nil
+	}
 	vmMap := cached.(*sync.Map)
 	vmMap.Delete(nodeName)