add e2e test for dual-stack secondary service IPs

Dual stack services can have two ClusterIPs, we already have tests that
exercise the connectivity from different scenarios to the first
ClusterIP of the service.

This PR adds a new functionality to the e2e network utils to enable
DualStack services, and replicate the same tests but using the
secondary ClusterIP, so we cover the connectivity to both cluster IPs.

test/e2e/framework/node/resource.go

@@ -20,11 +20,12 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
-	netutil "k8s.io/utils/net"
 	"net"
 	"strings"
 	"time"
 
+	netutil "k8s.io/utils/net"
+
 	"github.com/onsi/ginkgo"
 	"github.com/onsi/gomega"
 
@@ -249,6 +250,17 @@ func GetInternalIP(node *v1.Node) (string, error) {
 	return host, nil
 }
 
+// FirstAddressByTypeAndFamily returns the first address of the given type and family of each node.
+func FirstAddressByTypeAndFamily(nodelist *v1.NodeList, addrType v1.NodeAddressType, family v1.IPFamily) string {
+	for _, n := range nodelist.Items {
+		addresses := GetAddressesByTypeAndFamily(&n, addrType, family)
+		if len(addresses) > 0 {
+			return addresses[0]
+		}
+	}
+	return ""
+}
+
 // GetAddressesByTypeAndFamily returns a list of addresses of the given addressType for the given node
 // and filtered by IPFamily
 func GetAddressesByTypeAndFamily(node *v1.Node, addressType v1.NodeAddressType, family v1.IPFamily) (ips []string) {