Merge pull request #59868 from dims/automated-cherry-pick-of-#59749-u…

…pstream-release-1.9

Automatic merge from submit-queue.

Automated cherry pick of #59749: Detect CIDR IPv4 or IPv6 version to select nexthop

Cherry pick of #59749 on release-1.9.

#59749: Detect CIDR IPv4 or IPv6 version to select nexthop

```release-note
Fixing a bug in OpenStack cloud provider, where dual stack deployments (IPv4 and IPv6) did not work well when using kubenet as the network plugin.
```

pkg/cloudprovider/providers/openstack/openstack.go

@@ -22,6 +22,7 @@ import (
 	"fmt"
 	"io"
 	"io/ioutil"
+	"net"
 	"net/http"
 	"regexp"
 	"strings"
@@ -440,7 +441,7 @@ func getAddressesByName(client *gophercloud.ServiceClient, name types.NodeName)
 	return nodeAddresses(srv)
 }
 
-func getAddressByName(client *gophercloud.ServiceClient, name types.NodeName) (string, error) {
+func getAddressByName(client *gophercloud.ServiceClient, name types.NodeName, needIPv6 bool) (string, error) {
 	addrs, err := getAddressesByName(client, name)
 	if err != nil {
 		return "", err
@@ -449,12 +450,20 @@ func getAddressByName(client *gophercloud.ServiceClient, name types.NodeName) (s
 	}
 
 	for _, addr := range addrs {
-		if addr.Type == v1.NodeInternalIP {
+		isIPv6 := net.ParseIP(addr.Address).To4() == nil
+		if (addr.Type == v1.NodeInternalIP) && (isIPv6 == needIPv6) {
 			return addr.Address, nil
 		}
 	}
 
-	return addrs[0].Address, nil
+	for _, addr := range addrs {
+		isIPv6 := net.ParseIP(addr.Address).To4() == nil
+		if (addr.Type == v1.NodeExternalIP) && (isIPv6 == needIPv6) {
+			return addr.Address, nil
+		}
+	}
+	// It should never return an address from a different IP Address family than the one needed
+	return "", ErrNoAddressFound
 }
 
 // getAttachedInterfacesByID returns the node interfaces of the specified instance.

pkg/cloudprovider/providers/openstack/openstack_routes.go

@@ -18,6 +18,7 @@ package openstack
 
 import (
 	"errors"
+	"net"
 
 	"github.com/gophercloud/gophercloud"
 	"github.com/gophercloud/gophercloud/openstack/compute/v2/servers"
@@ -145,7 +146,10 @@ func (r *Routes) CreateRoute(clusterName string, nameHint string, route *cloudpr
 
 	onFailure := NewCaller()
 
-	addr, err := getAddressByName(r.compute, route.TargetNode)
+	ip, _, _ := net.ParseCIDR(route.DestinationCIDR)
+	isCIDRv6 := ip.To4() == nil
+	addr, err := getAddressByName(r.compute, route.TargetNode, isCIDRv6)
+
 	if err != nil {
 		return err
 	}
@@ -217,7 +221,10 @@ func (r *Routes) DeleteRoute(clusterName string, route *cloudprovider.Route) err
 
 	onFailure := NewCaller()
 
-	addr, err := getAddressByName(r.compute, route.TargetNode)
+	ip, _, _ := net.ParseCIDR(route.DestinationCIDR)
+	isCIDRv6 := ip.To4() == nil
+	addr, err := getAddressByName(r.compute, route.TargetNode, isCIDRv6)
+
 	if err != nil {
 		return err
 	}