Merge pull request #57644 from feiskyer/vmss-master

Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

 Reduce VirtualMachineScaleSetsClient#List calls for Azure cloud provider

**What this PR does / why we need it**:

For master nodes not managed by VMSS, current cloud provider would updateCaches each time when finding master nodes info. This could result in call limits of `VirtualMachineScaleSetsClient#List`. 

This PR adds a caches to those nodes which reduces the cache updating significantly.

**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
Continue of #43287.

**Special notes for your reviewer**:

**Release note**:

```release-note
NONE
```

pkg/cloudprovider/providers/azure/azure.go

@@ -132,7 +132,7 @@ type Config struct {
 	MaximumLoadBalancerRuleCount int `json:"maximumLoadBalancerRuleCount"`
 }
 
-// VirtualMachinesClient defines needed functions for azure network.VirtualMachinesClient
+// VirtualMachinesClient defines needed functions for azure compute.VirtualMachinesClient
 type VirtualMachinesClient interface {
 	CreateOrUpdate(resourceGroupName string, VMName string, parameters compute.VirtualMachine, cancel <-chan struct{}) (<-chan compute.VirtualMachine, <-chan error)
 	Get(resourceGroupName string, VMName string, expand compute.InstanceViewTypes) (result compute.VirtualMachine, err error)

pkg/cloudprovider/providers/azure/azure_util_vmss.go

@@ -76,15 +76,17 @@ type scaleSet struct {
 	cacheMutex sync.Mutex
 	// A local cache of scale sets. The key is scale set name and the value is a
 	// list of virtual machines belonging to the scale set.
-	cache map[string][]scaleSetVMInfo
+	cache                     map[string][]scaleSetVMInfo
+	availabilitySetNodesCache sets.String
 }
 
 // newScaleSet creates a new scaleSet.
 func newScaleSet(az *Cloud) VMSet {
 	ss := &scaleSet{
-		Cloud:           az,
-		availabilitySet: newAvailabilitySet(az),
-		cache:           make(map[string][]scaleSetVMInfo),
+		Cloud:                     az,
+		availabilitySet:           newAvailabilitySet(az),
+		availabilitySetNodesCache: sets.NewString(),
+		cache: make(map[string][]scaleSetVMInfo),
 	}
 
 	go wait.Until(func() {
@@ -179,6 +181,11 @@ func (ss *scaleSet) getCachedVirtualMachine(nodeName string) (scaleSetVMInfo, er
 		return vm, nil
 	}
 
+	// Known node not managed by scale sets.
+	if ss.availabilitySetNodesCache.Has(nodeName) {
+		return scaleSetVMInfo{}, cloudprovider.InstanceNotFound
+	}
+
 	// Update cache and try again.
 	if err = ss.updateCache(); err != nil {
 		return scaleSetVMInfo{}, err
@@ -188,6 +195,8 @@ func (ss *scaleSet) getCachedVirtualMachine(nodeName string) (scaleSetVMInfo, er
 		return vm, nil
 	}
 
+	// Node still not found, assuming it is not managed by scale sets.
+	ss.availabilitySetNodesCache.Insert(nodeName)
 	return scaleSetVMInfo{}, cloudprovider.InstanceNotFound
 }