Add missing node.address != "" condition in tests

It turns out to be a frequent bug that is revealed when nodes don't have
external IP addresses. In the test we assume that in such case there
won't be any addresses of type 'NodeExternalIp', which is invalid. In
such case there will be an address of type 'NodeExternalIP', but with
the empty 'Address' field.

Ref. kubernetes#76374

Author: mm4tt

test/e2e/framework/service_util.go

@@ -320,7 +320,7 @@ func (j *ServiceTestJig) CreateLoadBalancerService(namespace, serviceName string
 func GetNodeAddresses(node *v1.Node, addressType v1.NodeAddressType) (ips []string) {
 	for j := range node.Status.Addresses {
 		nodeAddress := &node.Status.Addresses[j]
-		if nodeAddress.Type == addressType {
+		if nodeAddress.Type == addressType && nodeAddress.Address != "" {
 			ips = append(ips, nodeAddress.Address)
 		}
 	}

test/e2e/framework/ssh.go

@@ -245,7 +245,7 @@ func IssueSSHCommandWithResult(cmd, provider string, node *v1.Node) (*SSHResult,
 	Logf("Getting external IP address for %s", node.Name)
 	host := ""
 	for _, a := range node.Status.Addresses {
-		if a.Type == v1.NodeExternalIP {
+		if a.Type == v1.NodeExternalIP && a.Address != "" {
 			host = net.JoinHostPort(a.Address, sshPort)
 			break
 		}
@@ -254,7 +254,7 @@ func IssueSSHCommandWithResult(cmd, provider string, node *v1.Node) (*SSHResult,
 	if host == "" {
 		// No external IPs were found, let's try to use internal as plan B
 		for _, a := range node.Status.Addresses {
-			if a.Type == v1.NodeInternalIP {
+			if a.Type == v1.NodeInternalIP && a.Address != "" {
 				host = net.JoinHostPort(a.Address, sshPort)
 				break
 			}

test/e2e/framework/util.go

@@ -3424,7 +3424,7 @@ func NodeAddresses(nodelist *v1.NodeList, addrType v1.NodeAddressType) []string
 	hosts := []string{}
 	for _, n := range nodelist.Items {
 		for _, addr := range n.Status.Addresses {
-			if addr.Type == addrType {
+			if addr.Type == addrType && addr.Address != "" {
 				hosts = append(hosts, addr.Address)
 				break
 			}
@@ -4942,7 +4942,7 @@ func GetNodeExternalIP(node *v1.Node) (string, error) {
 	Logf("Getting external IP address for %s", node.Name)
 	host := ""
 	for _, a := range node.Status.Addresses {
-		if a.Type == v1.NodeExternalIP {
+		if a.Type == v1.NodeExternalIP && a.Address != "" {
 			host = net.JoinHostPort(a.Address, sshPort)
 			break
 		}