Hi All,

I have a wierd problem which I can't figure out muself.

I have this simple container running on my docker with default launch command, i.e:

 docker run -it --rm --cap-add NET_ADMIN -p 1080:1080 -e USER=<email> -e PASS='<pass>' -e TECHNOLOGY=NordLynx twitchax/nordvpn-proxy 

It's connected to the default bridge and it exposes socks proxy on port 1080. I can reach that proxy if I connect via bridge IP (i.e. 172.17.0.4 ) but I cannot connect to it via host IP.

While I have Portainer on the same default bridge and I can access it via forwarded port on the host w/o any issues. Any ideas what's wrong here?

root@ubuntu:~# docker port nostalgic_galois
1080/tcp -> 0.0.0.0:1080

root@ubuntu:~# netstat -tulp | grep socks
tcp6       0      0 [::]:socks              [::]:*                  LISTEN      3539426/docker-proxy

root@ubuntu:~# docker ps
CONTAINER ID        IMAGE                                            COMMAND                  CREATED             STATUS                    PORTS                                                                         NAMES
f6b9398930b2        twitchax/nordvpn-proxy                           "/start.sh"              14 hours ago        Up 14 hours (unhealthy)   0.0.0.0:1080->1080/tcp                                                        nostalgic_galois
...

root@ubuntu:~# docker network inspect bridge
[
    {
        "Name": "bridge",
        "Id": "d2e53fb8e317f7f723dd635f4a4661f86a056ba5d74b11cb5dd925a688aed1b3",
        "Created": "2020-11-10T00:47:59.415805106 03:00",
        "Scope": "local",
        "Driver": "bridge",
        "EnableIPv6": false,
        "IPAM": {
            "Driver": "default",
            "Options": null,
            "Config": [
                {
                    "Subnet": "172.17.0.0/16",
                    "Gateway": "172.17.0.1"
                }
            ]
        },
        "Internal": false,
        "Attachable": false,
        "Ingress": false,
        "ConfigFrom": {
            "Network": ""
        },
        "ConfigOnly": false,
        "Containers": {
........
            "d4931c221fbb05c8fb2d994f19200704052969c73127d7ea0e06ed997006e2b2": {
                "Name": "portainer",
                "EndpointID": "03805ede835cde43b52afcb83c45a4999dc1cdc526807736ebb23e6e8d1f217d",
                "MacAddress": "02:42:ac:11:00:02",
                "IPv4Address": "172.17.0.2/16",
                "IPv6Address": ""
            },
            "f6b9398930b2291939a5a4fa845a4f993ac1ce22bcb01374eac5e6147571b562": {
                "Name": "nostalgic_galois",
                "EndpointID": "3e79589714118ba1a687840e991161d6b549fcc2c72960f2e9a14175fc0966b6",
                "MacAddress": "02:42:ac:11:00:04",
                "IPv4Address": "172.17.0.4/16",
                "IPv6Address": ""
            }
        },
        "Options": {
            "com.docker.network.bridge.default_bridge": "true",
            "com.docker.network.bridge.enable_icc": "true",
            "com.docker.network.bridge.enable_ip_masquerade": "true",
            "com.docker.network.bridge.host_binding_ipv4": "0.0.0.0",
            "com.docker.network.bridge.name": "docker0",
            "com.docker.network.driver.mtu": "1500"
        },
        "Labels": {}
    }
]

and this is from within container:

root@ubuntu:~# docker exec nostalgic_galois ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
3: nordlynx: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1420 qdisc fq_codel state UNKNOWN group default qlen 500
    link/none
    inet 10.5.0.2/16 scope global nordlynx
       valid_lft forever preferred_lft forever
232: eth0@if233: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default
    link/ether 02:42:ac:11:00:04 brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 172.17.0.4/16 brd 172.17.255.255 scope global eth0
       valid_lft forever preferred_lft forever

​

some logs from proxy:

2020-11-09 22:13:24,873 INFO  [rusty_socks] Listen IP:    172.17.0.4
2020-11-09 22:13:24,874 INFO  [rusty_socks] Endpoint IP:  10.5.0.2
2020-11-09 22:13:24,876 INFO  [rusty_socks] Port:         1080
2020-11-09 22:13:24,877 INFO  [rusty_socks] Buffer Size:  2048
2020-11-09 22:13:24,877 INFO  [rusty_socks] Read Timeout: 5000
2020-11-09 22:13:24,878 INFO  [rusty_socks] Accept CIDR:  0.0.0.0/0
2020-11-09 22:13:24,879 INFO  [rusty_socks] Listening on tcp://172.17.0.4:1080 ...
2020-11-09 22:14:23,817 INFO  [rusty_socks::connection] [1eRj] 172.17.0.1:52310 => 172.17.0.4:1080 => 10.5.0.2:49857 => x.x.x.x:80

​