podman localhost IPv6 portmapping

portmap plugin  does not support to do portmapping on the ::1 address,
because it does not have the route_localnet workaround implemented
in the kernel for IPv4.

If we want to do portmapping to the localhost address for IPv6 with
podman, we don't use it for the kubeconfig because it will not work.
Instead, we return the direct parameters, because podman only runs
in Linux, that guarantees that pods are reachable from the host.

pkg/cluster/internal/providers/podman/provider.go

@@ -222,23 +222,31 @@ func (p *Provider) GetAPIServerEndpoint(cluster string) (string, error) {
 				return "", err
 			}
 			for _, pm := range v {
-				if containerPort == common.APIServerInternalPort && protocol == "tcp" {
+				if containerPort == common.APIServerInternalPort && protocol == "tcp" && pm.HostIP != "::1" {
 					return net.JoinHostPort(pm.HostIP, pm.HostPort), nil
 				}
 			}
 		}
-	}
-	var portMappings19 []portMapping19
-	if err := json.Unmarshal([]byte(lines[0]), &portMappings19); err != nil {
-		return "", errors.Errorf("invalid network details: %v", err)
-	}
-	for _, pm := range portMappings19 {
-		if pm.ContainerPort == common.APIServerInternalPort && pm.Protocol == "tcp" {
-			return net.JoinHostPort(pm.HostIP, strconv.Itoa(int(pm.HostPort))), nil
+	} else {
+		var portMappings19 []portMapping19
+		if err := json.Unmarshal([]byte(lines[0]), &portMappings19); err != nil {
+			return "", errors.Errorf("invalid network details: %v", err)
+		}
+		for _, pm := range portMappings19 {
+			if pm.ContainerPort == common.APIServerInternalPort && pm.Protocol == "tcp" && pm.HostIP != "::1" {
+				return net.JoinHostPort(pm.HostIP, strconv.Itoa(int(pm.HostPort))), nil
+			}
 		}
 	}
 
-	return "", errors.Errorf("unable to find apiserver endpoint information")
+	// podman does not support portmapping on localhost for IPv6
+	// if we don't find the portmapping we return the API IP and Port directly
+	// because it must be reachable for podman and IPv6
+	_, ipv6, err := n.IP()
+	if ipv6 == "" || err != nil {
+		return "", errors.Errorf("unable to find apiserver endpoint information")
+	}
+	return net.JoinHostPort(ipv6, fmt.Sprintf("%d", common.APIServerInternalPort)), nil
 }
 
 // GetAPIServerInternalEndpoint is part of the providers.Provider interface