Retrieve subnet from vnet subnets.addressPrefixes field

In some Azure clusters where the workers subnet is defined on the vnet
using addressPrefixes array instead of addressPrefix, so retrieve subnet
value from vnet's subnet.addressPrefixes field when subnet.addressPrefix
is not set.

Signed-off-by: Periyasamy Palanisamy <[email protected]>

Author: pperiyasamy

pkg/cloudprovider/azure.go

@@ -3,22 +3,22 @@ package cloudprovider
 import (
 	"context"
 	"fmt"
-	"github.com/Azure/azure-sdk-for-go/sdk/azcore/runtime"
-	"k8s.io/utils/ptr"
 	"net"
 	"os"
 	"strings"
 	"sync"
 	"time"
 
+	"github.com/Azure/azure-sdk-for-go/sdk/azcore/runtime"
+	"k8s.io/utils/ptr"
+
 	"github.com/Azure/azure-sdk-for-go/sdk/azcore"
 	"github.com/Azure/azure-sdk-for-go/sdk/azcore/arm"
 	"github.com/Azure/azure-sdk-for-go/sdk/azcore/cloud"
 	"github.com/Azure/azure-sdk-for-go/sdk/azcore/policy"
 	"github.com/Azure/azure-sdk-for-go/sdk/azidentity"
 	"github.com/Azure/azure-sdk-for-go/sdk/resourcemanager/compute/armcompute"
 	"github.com/Azure/azure-sdk-for-go/sdk/resourcemanager/network/armnetwork/v6"
-	"github.com/Azure/go-autorest/autorest/azure"
 	azureapi "github.com/Azure/go-autorest/autorest/azure"
 	"github.com/Azure/msi-dataplane/pkg/dataplane"
 	v1 "github.com/openshift/api/cloudnetwork/v1"
@@ -44,7 +44,7 @@ type Azure struct {
 	CloudProvider
 	platformStatus               *configv1.AzurePlatformStatus
 	resourceGroup                string
-	env                          azure.Environment
+	env                          azureapi.Environment
 	vmClient                     *armcompute.VirtualMachinesClient
 	virtualNetworkClient         *armnetwork.VirtualNetworksClient
 	networkClient                *armnetwork.InterfacesClient
@@ -124,13 +124,13 @@ func (a *Azure) initCredentials() error {
 
 	// Pick the Azure "Environment", which is just a named set of API endpoints.
 	if a.cfg.APIOverride != "" {
-		a.env, err = azure.EnvironmentFromURL(a.cfg.APIOverride)
+		a.env, err = azureapi.EnvironmentFromURL(a.cfg.APIOverride)
 	} else {
 		name := a.cfg.AzureEnvironment
 		if name == "" {
 			name = "AzurePublicCloud"
 		}
-		a.env, err = azure.EnvironmentFromName(name)
+		a.env, err = azureapi.EnvironmentFromName(name)
 	}
 	if err != nil {
 		return fmt.Errorf("failed to initialize Azure environment: %w", err)
@@ -223,13 +223,13 @@ OuterLoop:
 				if err != nil {
 					return fmt.Errorf("error looking up backend address pool %s with ID %s: %v", ptr.Deref(pool.Name, ""), ptr.Deref(pool.ID, ""), err)
 				}
-				if realPool.Properties.LoadBalancerBackendAddresses != nil && len(realPool.Properties.LoadBalancerBackendAddresses) > 0 {
+				if len(realPool.Properties.LoadBalancerBackendAddresses) > 0 {
 					if realPool.Properties.OutboundRule != nil {
 						loadBalancerBackendAddressPoolsArgument = nil
 						attachedOutboundRule = realPool.Properties.OutboundRule
 						break OuterLoop
 					}
-					if realPool.Properties.OutboundRules != nil && len(realPool.Properties.OutboundRules) > 0 {
+					if len(realPool.Properties.OutboundRules) > 0 {
 						loadBalancerBackendAddressPoolsArgument = nil
 						attachedOutboundRule = (realPool.Properties.OutboundRules)[0]
 						break OuterLoop
@@ -447,7 +447,7 @@ func (a *Azure) getNetworkInterfaces(instance *armcompute.VirtualMachine) ([]arm
 	if instance.Properties == nil || instance.Properties.NetworkProfile == nil {
 		return nil, NoNetworkInterfaceError
 	}
-	if instance.Properties.NetworkProfile.NetworkInterfaces == nil || len(instance.Properties.NetworkProfile.NetworkInterfaces) == 0 {
+	if len(instance.Properties.NetworkProfile.NetworkInterfaces) == 0 {
 		return nil, NoNetworkInterfaceError
 	}
 	networkInterfaces := []armnetwork.Interface{}
@@ -577,17 +577,23 @@ func (a *Azure) getAddressPrefixes(networkInterface armnetwork.Interface) ([]*st
 	// FIXME: This might not work for IPv6.
 	if virtualNetwork.Properties != nil && virtualNetwork.Properties.Subnets != nil {
 		for _, vns := range virtualNetwork.Properties.Subnets {
-			if vns.Name != nil && vns.Properties.AddressPrefix != nil &&
-				ptr.Deref(vns.Name, "") == subnetName {
-				return []*string{vns.Properties.AddressPrefix}, nil
+			if vns.Name != nil && ptr.Deref(vns.Name, "") == subnetName {
+				if vns.Properties.AddressPrefix != nil {
+					return []*string{vns.Properties.AddressPrefix}, nil
+				}
+				// In some cases, addressPrefixes is set with single element.
+				// so use it when addressPrefix is not available.
+				if len(vns.Properties.AddressPrefixes) > 0 {
+					return vns.Properties.AddressPrefixes, nil
+				}
 			}
 		}
 	}
 
 	if virtualNetwork.Properties.AddressSpace == nil {
 		return nil, fmt.Errorf("nil subnet address space")
 	}
-	if virtualNetwork.Properties.AddressSpace.AddressPrefixes == nil || len(virtualNetwork.Properties.AddressSpace.AddressPrefixes) == 0 {
+	if len(virtualNetwork.Properties.AddressSpace.AddressPrefixes) == 0 {
 		return nil, fmt.Errorf("no subnet address prefixes defined")
 	}
 	return virtualNetwork.Properties.AddressSpace.AddressPrefixes, nil
@@ -668,11 +674,11 @@ func getNameFromResourceID(id string) string {
 func ParseCloudEnvironment(env azureapi.Environment) cloud.Configuration {
 	var cloudConfig cloud.Configuration
 	switch env {
-	case azure.ChinaCloud:
+	case azureapi.ChinaCloud:
 		cloudConfig = cloud.AzureChina
-	case azure.USGovernmentCloud:
+	case azureapi.USGovernmentCloud:
 		cloudConfig = cloud.AzureGovernment
-	case azure.PublicCloud:
+	case azureapi.PublicCloud:
 		cloudConfig = cloud.AzurePublic
 	default: // AzureStackCloud
 		cloudConfig = cloud.Configuration{

pkg/cloudprovider/cloudprovider.go

@@ -4,14 +4,15 @@ import (
 	"context"
 	"errors"
 	"fmt"
-	apifeatures "github.com/openshift/api/features"
-	configv1 "github.com/openshift/api/config/v1"
-	"github.com/openshift/library-go/pkg/operator/configobserver/featuregates"
 	"net"
 	"os"
 	"path/filepath"
 	"sync"
 
+	configv1 "github.com/openshift/api/config/v1"
+	apifeatures "github.com/openshift/api/features"
+	"github.com/openshift/library-go/pkg/operator/configobserver/featuregates"
+
 	v1 "github.com/openshift/api/cloudnetwork/v1"
 	corev1 "k8s.io/api/core/v1"
 )