Repository: kubernetes-sigs/cloud-provider-azure
Pull request #2807 (2022-11-21 02:07:29)

[release-1.24] fix public ip list call reduce
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#### What type of PR is this?
/kind bug
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#### What this PR does / why we need it:
Original `pip = &pipList` does not modify the passed slice actually.
#### Which issue(s) this PR fixes:
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related #2707 

#### Special notes for your reviewer:

#### Does this PR introduce a user-facing change?
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```release-note
Fix to reduce PublicIPAddress list arm calls
```

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```docs

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Patch:
diff --git a/pkg/provider/azure_loadbalancer.go b/pkg/provider/azure_loadbalancer.go
index 7b1e208d6..72cfa0e73 100644
--- a/pkg/provider/azure_loadbalancer.go
+++ b/pkg/provider/azure_loadbalancer.go
@@ -85,7 +85,8 @@ func (az *Cloud) GetLoadBalancer(ctx context.Context, clusterName string, servic
 	// there is a chance that we could orphan public IP resources while we delete the load balancer (kubernetes/kubernetes#80571).
 	// We need to make sure the existence of the load balancer depends on the load balancer resource and public IP resource on Azure.
 	existsPip := func() bool {
-		pipName, _, err := az.determinePublicIPName(clusterName, service, nil)
+		var pips []network.PublicIPAddress
+		pipName, _, err := az.determinePublicIPName(clusterName, service, &pips)
 		if err != nil {
 			return false
 		}
@@ -140,7 +141,8 @@ func (az *Cloud) reconcileService(ctx context.Context, clusterName string, servi
 		return nil, err
 	}
 
-	lbStatus, fipConfig, err := az.getServiceLoadBalancerStatus(service, lb, nil)
+	var pips []network.PublicIPAddress
+	lbStatus, fipConfig, err := az.getServiceLoadBalancerStatus(service, lb, &pips)
 	if err != nil {
 		klog.Errorf("getServiceLoadBalancerStatus(%s) failed: %v", serviceName, err)
 		if !errors.Is(err, ErrorNotVmssInstance) {
@@ -644,7 +646,7 @@ func (az *Cloud) getServiceLoadBalancer(service *v1.Service, clusterName string,
 	}
 
 	// reuse pip list to reduce api call
-	var pips *[]network.PublicIPAddress
+	var pips []network.PublicIPAddress
 
 	// check if the service already has a load balancer
 	for i := range existingLBs {
@@ -682,7 +684,7 @@ func (az *Cloud) getServiceLoadBalancer(service *v1.Service, clusterName string,
 			continue
 		}
 		var fipConfig *network.FrontendIPConfiguration
-		status, fipConfig, err = az.getServiceLoadBalancerStatus(service, &existingLB, pips)
+		status, fipConfig, err = az.getServiceLoadBalancerStatus(service, &existingLB, &pips)
 		if err != nil {
 			return nil, nil, false, err
 		}
@@ -816,6 +818,7 @@ func (az *Cloud) selectLoadBalancer(clusterName string, service *v1.Service, exi
 	return selectedLB, existsLb, nil
 }
 
+// pips: a non-nil pointer to a slice of existing PIPs, if the slice being pointed to is nil, listPIP would be called when needed and the slice would be filled
 func (az *Cloud) getServiceLoadBalancerStatus(service *v1.Service, lb *network.LoadBalancer, pips *[]network.PublicIPAddress) (status *v1.LoadBalancerStatus, fipConfig *network.FrontendIPConfiguration, err error) {
 	if lb == nil {
 		klog.V(10).Info("getServiceLoadBalancerStatus: lb is nil")
@@ -882,6 +885,7 @@ func (az *Cloud) getServiceLoadBalancerStatus(service *v1.Service, lb *network.L
 	return nil, nil, nil
 }
 
+// pips: a non-nil pointer to a slice of existing PIPs, if the slice being pointed to is nil, listPIP would be called when needed and the slice would be filled
 func (az *Cloud) determinePublicIPName(clusterName string, service *v1.Service, pips *[]network.PublicIPAddress) (string, bool, error) {
 	var shouldPIPExisted bool
 
@@ -915,13 +919,17 @@ func (az *Cloud) determinePublicIPName(clusterName string, service *v1.Service,
 	return "", shouldPIPExisted, fmt.Errorf("user supplied IP Address %s was not found in resource group %s", loadBalancerIP, pipResourceGroup)
 }
 
+// pips: a non-nil pointer to a slice of existing PIPs, if the slice being pointed to is nil, listPIP would be called when needed and the slice would be filled
 func (az *Cloud) findMatchedPIPByLoadBalancerIP(service *v1.Service, loadBalancerIP, pipResourceGroup string, pips *[]network.PublicIPAddress) (*network.PublicIPAddress, error) {
 	if pips == nil {
+		// this should not happen
+		return nil, fmt.Errorf("findMatchedPIPByLoadBalancerIP: nil pip list passed")
+	} else if *pips == nil {
 		pipList, err := az.ListPIP(service, pipResourceGroup)
 		if err != nil {
 			return nil, err
 		}
-		pips = &pipList
+		*pips = pipList
 	}
 	for _, pip := range *pips {
 		if pip.PublicIPAddressPropertiesFormat.IPAddress != nil &&
@@ -1137,10 +1145,9 @@ func (az *Cloud) reconcileIPSettings(pip *network.PublicIPAddress, service *v1.S
 	serviceName := getServiceName(service)
 	ipv6 := utilnet.IsIPv6String(service.Spec.ClusterIP)
 	if ipv6 {
-		klog.V(2).Infof("service(%s): pip(%s) - creating as ipv6 for clusterIP:%v", serviceName, *pip.Name, service.Spec.ClusterIP)
-
 		if !strings.EqualFold(string(pip.PublicIPAddressVersion), string(network.IPVersionIPv6)) {
 			pip.PublicIPAddressVersion = network.IPVersionIPv6
+			klog.V(2).Infof("service(%s): pip(%s) - creating as ipv6 for clusterIP:%v", serviceName, *pip.Name, service.Spec.ClusterIP)
 			changed = true
 		}
 
@@ -1155,10 +1162,9 @@ func (az *Cloud) reconcileIPSettings(pip *network.PublicIPAddress, service *v1.S
 			changed = true
 		}
 	} else {
-		klog.V(2).Infof("service(%s): pip(%s) - creating as ipv4 for clusterIP:%v", serviceName, *pip.Name, service.Spec.ClusterIP)
-
 		if !strings.EqualFold(string(pip.PublicIPAddressVersion), string(network.IPVersionIPv4)) {
 			pip.PublicIPAddressVersion = network.IPVersionIPv4
+			klog.V(2).Infof("service(%s): pip(%s) - creating as ipv4 for clusterIP:%v", serviceName, *pip.Name, service.Spec.ClusterIP)
 			changed = true
 		}
 	}
@@ -1339,6 +1345,7 @@ func getDomainNameLabel(pip *network.PublicIPAddress) string {
 	return to.String(pip.PublicIPAddressPropertiesFormat.DNSSettings.DomainNameLabel)
 }
 
+// pips: a non-nil pointer to a slice of existing PIPs, if the slice being pointed to is nil, listPIP would be called when needed and the slice would be filled
 func (az *Cloud) isFrontendIPChanged(clusterName string, config network.FrontendIPConfiguration, service *v1.Service, lbFrontendIPConfigName string, pips *[]network.PublicIPAddress) (bool, error) {
 	isServiceOwnsFrontendIP, isPrimaryService, err := az.serviceOwnsFrontendIP(config, service, pips)
 	if err != nil {
@@ -1774,12 +1781,12 @@ func (az *Cloud) reconcileFrontendIPConfigs(clusterName string, service *v1.Serv
 	}
 
 	// Save pip list so it can be reused in loop
-	var pips *[]network.PublicIPAddress
+	var pips []network.PublicIPAddress
 	var ownedFIPConfig *network.FrontendIPConfiguration
 	if !wantLb {
 		for i := len(newConfigs) - 1; i >= 0; i-- {
 			config := newConfigs[i]
-			isServiceOwnsFrontendIP, _, err := az.serviceOwnsFrontendIP(config, service, pips)
+			isServiceOwnsFrontendIP, _, err := az.serviceOwnsFrontendIP(config, service, &pips)
 			if err != nil {
 				return nil, toDeleteConfigs, false, err
 			}
@@ -1817,13 +1824,13 @@ func (az *Cloud) reconcileFrontendIPConfigs(clusterName string, service *v1.Serv
 		)
 		for i := len(newConfigs) - 1; i >= 0; i-- {
 			config := newConfigs[i]
-			isServiceOwnsFrontendIP, _, _ := az.serviceOwnsFrontendIP(config, service, pips)
+			isServiceOwnsFrontendIP, _, _ := az.serviceOwnsFrontendIP(config, service, &pips)
 			if !isServiceOwnsFrontendIP {
 				klog.V(4).Infof("reconcileFrontendIPConfigs for service (%s): the frontend IP configuration %s does not belong to the service", serviceName, to.String(config.Name))
 				continue
 			}
-			klog.V(4).Infof("reconcileFrontendIPConfigs for service (%s): checking owned frontend IP cofiguration %s", serviceName, to.String(config.Name))
-			isFipChanged, err = az.isFrontendIPChanged(clusterName, config, service, defaultLBFrontendIPConfigName, pips)
+			klog.V(4).Infof("reconcileFrontendIPConfigs for service (%s): checking owned frontend IP configuration %s", serviceName, to.String(config.Name))
+			isFipChanged, err = az.isFrontendIPChanged(clusterName, config, service, defaultLBFrontendIPConfigName, &pips)
 			if err != nil {
 				return nil, toDeleteConfigs, false, err
 			}
@@ -1837,7 +1844,7 @@ func (az *Cloud) reconcileFrontendIPConfigs(clusterName string, service *v1.Serv
 			break
 		}
 
-		ownedFIPConfig, _, err = az.findFrontendIPConfigOfService(&newConfigs, service, pips)
+		ownedFIPConfig, _, err = az.findFrontendIPConfigOfService(&newConfigs, service, &pips)
 		if err != nil {
 			return nil, toDeleteConfigs, false, err
 		}
@@ -1885,7 +1892,7 @@ func (az *Cloud) reconcileFrontendIPConfigs(clusterName string, service *v1.Serv
 
 				fipConfigurationProperties = &configProperties
 			} else {
-				pipName, shouldPIPExisted, err := az.determinePublicIPName(clusterName, service, pips)
+				pipName, shouldPIPExisted, err := az.determinePublicIPName(clusterName, service, &pips)
 				if err != nil {
 					return nil, toDeleteConfigs, false, err
 				}


Test patch:
diff --git a/pkg/provider/azure_loadbalancer_test.go b/pkg/provider/azure_loadbalancer_test.go
index 0cebf5453..7a8d8fd29 100644
--- a/pkg/provider/azure_loadbalancer_test.go
+++ b/pkg/provider/azure_loadbalancer_test.go
@@ -2041,6 +2041,61 @@ func TestIsFrontendIPChanged(t *testing.T) {
 	}
 }
 
+func TestFindMatchedPIPByLoadBalancerIP(t *testing.T) {
+	ctrl := gomock.NewController(t)
+	defer ctrl.Finish()
+
+	testPIP := network.PublicIPAddress{
+		Name: to.StringPtr("pipName"),
+		PublicIPAddressPropertiesFormat: &network.PublicIPAddressPropertiesFormat{
+			IPAddress: to.StringPtr("1.2.3.4"),
+		},
+	}
+	var nilPIPs []network.PublicIPAddress
+	testCases := []struct {
+		desc          string
+		pips          *[]network.PublicIPAddress
+		pipListResult []network.PublicIPAddress
+		expectedPIPs  *[]network.PublicIPAddress
+		expectedError bool
+	}{
+		{
+			desc:          "findMatchedPIPByLoadBalancerIP shall return error if pip slice passed in is nil",
+			expectedError: true,
+		},
+		{
+			desc:          "findMatchedPIPByLoadBalancerIP shall list pips if pip slice passed in is nil",
+			pips:          &nilPIPs,
+			pipListResult: []network.PublicIPAddress{testPIP},
+			expectedPIPs:  &[]network.PublicIPAddress{testPIP},
+		},
+		{
+			desc:          "findMatchedPIPByLoadBalancerIP shall not list pip again if pip slice is empty",
+			pips:          &[]network.PublicIPAddress{},
+			expectedPIPs:  &[]network.PublicIPAddress{},
+			expectedError: true, // pip not found
+		},
+		{
+			desc:         "findMatchedPIPByLoadBalancerIP shall not list pip again if pip slice already has pips",
+			pips:         &[]network.PublicIPAddress{testPIP},
+			expectedPIPs: &[]network.PublicIPAddress{testPIP},
+		},
+	}
+	for i, test := range testCases {
+		az := GetTestCloud(ctrl)
+		service := getTestService("test1", v1.ProtocolTCP, nil, false, 80)
+		setServiceLoadBalancerIP(&service, "1.2.3.4")
+
+		mockPIPsClient := az.PublicIPAddressesClient.(*mockpublicipclient.MockInterface)
+		if test.pipListResult != nil {
+			mockPIPsClient.EXPECT().List(gomock.Any(), "rg").Return(test.pipListResult, nil)
+		}
+		_, err := az.findMatchedPIPByLoadBalancerIP(&service, "1.2.3.4", "rg", test.pips)
+		assert.Equal(t, test.expectedPIPs, test.pips, "TestCase[%d]: %s", i, test.desc)
+		assert.Equal(t, test.expectedError, err != nil, "TestCase[%d]: %s", i, test.desc)
+	}
+}
+
 func TestDeterminePublicIPName(t *testing.T) {
 	ctrl := gomock.NewController(t)
 	defer ctrl.Finish()
@@ -2096,7 +2151,8 @@ func TestDeterminePublicIPName(t *testing.T) {
 				t.Fatalf("TestCase[%d] meets unexpected error: %v", i, err)
 			}
 		}
-		ip, _, err := az.determinePublicIPName("testCluster", &service, nil)
+		var pips []network.PublicIPAddress
+		ip, _, err := az.determinePublicIPName("testCluster", &service, &pips)
 		assert.Equal(t, test.expectedIP, ip, "TestCase[%d]: %s", i, test.desc)
 		assert.Equal(t, test.expectedError, err != nil, "TestCase[%d]: %s", i, test.desc)
 	}
@@ -3989,7 +4045,7 @@ func TestReconcilePublicIP(t *testing.T) {
 				return nil
 			})
 
-			mockPIPsClient.EXPECT().List(gomock.Any(), "rg").Return(test.existingPIPs, nil).AnyTimes()
+			mockPIPsClient.EXPECT().List(gomock.Any(), "rg").Return(test.existingPIPs, nil)
 			if i == 2 {
 				mockPIPsClient.EXPECT().Get(gomock.Any(), "rg", "testCluster-atest1", gomock.Any()).Return(network.PublicIPAddress{}, &retry.Error{HTTPStatusCode: http.StatusNotFound}).Times(1)
 				mockPIPsClient.EXPECT().Get(gomock.Any(), "rg", "testCluster-atest1", gomock.Any()).Return(network.PublicIPAddress{ID: to.StringPtr("/subscriptions/subscription/resourceGroups/rg/providers/Microsoft.Network/publicIPAddresses/testCluster-atest1")}, nil).Times(1)