Swarm ipv6 to ipv4 containers

[ghost]

Hi ,

We have a Swarm cluster whare all Hosts are IPv6 only. Swarm was created using ,
docker swarm init --advertise-addr [2001:db8:1:100::20]:2377 --listen-addr [2001:db8:1:100::20]:2377

our containers are IPv4 Only.
we need some mechanism that will allow incoming IPv6 traffic to services 'converted' and pushed to the containers as IPv4 . [converting our containers to IPv6 is not feasible at the moment since is will require major code changes :( ]

tried several configuration for docker service and docker_gwbridge , but none works .
currently trying to check it wilh simple nginx web.

My docker_bridge inspect:

    {
        "Name": "docker_gwbridge",
        "Id": "33b561a887b41324823e82ac8d99df2d73a9a7846749880dce2531bc6583a09e",
        "Created": "2019-12-05T17:47:00.947690828+02:00",
        "Scope": "local",
        "Driver": "bridge",
        "EnableIPv6": true,
        "IPAM": {
            "Driver": "default",
            "Options": {},
            "Config": [
                {
                    "Subnet": "172.18.0.0/16",
                    "Gateway": "172.18.0.1"
                },
                {
                    "Subnet": "2001:db8:18::/64",
                    "Gateway": "2001:db8:18::1"
                }
            ]
        },
        "Internal": false,
        "Attachable": false,
        "Ingress": false,
        "ConfigFrom": {
            "Network": ""
        },
        "ConfigOnly": false,
        "Containers": {
            "6063b0e7360a9476c5217a7780092e3000e2a8dac8e84e4f010ad153e8daaa3b": {
                "Name": "gateway_aba9e8a4ac32",
                "EndpointID": "1202c8e936221b71a8aadd6018e0b96b095679ef70fbcc32c6e6cd0de4ef8846",
                "MacAddress": "02:42:ac:12:00:03",
                "IPv4Address": "172.18.0.3/16",
                "IPv6Address": "2001:db8:18::3/64"
            },
            "ingress-sbox": {
                "Name": "gateway_ingress-sbox",
                "EndpointID": "f06663de793a651e328ab773b16143f21cad37f83e08eafe235d4c2f70e270eb",
                "MacAddress": "02:42:ac:12:00:02",
                "IPv4Address": "172.18.0.2/16",
                "IPv6Address": "2001:db8:18::2/64"
            }
        },
        "Options": {
            "com.docker.network.bridge.enable_icc": "false",
            "com.docker.network.bridge.enable_ip_masquerade": "true",
            "com.docker.network.bridge.name": "docker_gwbridge"
        },
        "Labels": {}
    }
]

My /etc/docker/daemon.json :

{
"ipv6": true,
"fixed-cidr-v6": "2001:db8:18:1::/64"
}

My container inspect:

 },
        "NetworkSettings": {
            "Bridge": "",
            "SandboxID": "aba9e8a4ac325750e30dc9a52de80f874a92641a71e3926bb84bb6727d562fed",
            "HairpinMode": false,
            "LinkLocalIPv6Address": "",
            "LinkLocalIPv6PrefixLen": 0,
            "Ports": {
                "80/tcp": null
            },
            "SandboxKey": "/var/run/docker/netns/aba9e8a4ac32",
            "SecondaryIPAddresses": null,
            "SecondaryIPv6Addresses": null,
            "EndpointID": "",
            "Gateway": "",
            "GlobalIPv6Address": "",
            "GlobalIPv6PrefixLen": 0,
            "IPAddress": "",
            "IPPrefixLen": 0,
            "IPv6Gateway": "",
            "MacAddress": "",
            "Networks": {
                "ingress": {
                    "IPAMConfig": {
                        "IPv4Address": "10.0.0.4"
                    },
                    "Links": null,
                    "Aliases": [
                        "6063b0e7360a"
                    ],
                    "NetworkID": "vg8sxhfwn673soqya849ho33m",
                    "EndpointID": "46ef4c31312dc2092cb762ed56b7d33feea1872ae7ab4e0f371ce794bcfe7b1b",
                    "Gateway": "",
                    "IPAddress": "10.0.0.4",
                    "IPPrefixLen": 24,
                    "IPv6Gateway": "",
                    "GlobalIPv6Address": "",
                    "GlobalIPv6PrefixLen": 0,
                    "MacAddress": "02:42:0a:00:00:04",
                    "DriverOpts": null
                }

Any help is welcomed and appriciated.

Thanks
Avi.