Instead of configuring multiple containers to use a VPN, we can setup a VPN container and route the other containers traffic through this container. This post will outline how to do that with dperson’s OpenVPN Container.

I’m a huge fan of docker-compose, so here we go:

version: "3.3"
services:
  openvpn-client:
    image: dperson/openvpn-client
    cap_add:
      - net_admin
    security_opt:
      - label:disable
    container_name: openvpn-client
    hostname: openvpn-client
    environment:
      - PUID=1000
      - PGID=1000
    volumes:
      - /dev/net:/dev/net:z
      - /volumes/openvpn-client/vpn/:/vpn
    restart: always

The net_admin capability according to the documentation “perform various network-related operations”. This would make sense since an additional network interface is configured for a VPN connection. The label:disable definition is to disable label confinement.

In this setup, you will need to put the .ovpn profile that you wish to connect to under the /volumes/openvpn-client/vpn/ directory.

(Optional) Username/Password Setup

In the event you need a username and password to connect, create a file called pass.txt in the same directory as your ovpn profile. The file pass.txt will contain the username in the first line and the password in the second line. Then in your ovpn profile make sure you have a line that says auth-user-pass pass.txt.

Routing Traffic through VPN

Let’s say your ISP throttles torrent connections and you want to route your qBittorrent container so that you can download Linux distributions faster. Here’s how you can define it in the docker-compose file.

qbittorrent:
  image: linuxserver/qbittorrent
  container_name: qbittorrent
  environment:
    - PUID=1000
    - PGID=1000
    - UMASK_SET=022
    - WEBUI_PORT=8000
  volumes:
    - /volumes/qbittorrent/config:/config
    - /volumes/qbittorrent/downloads:/downloads
  network_mode: service:openvpn-client
  restart: always

Network Workarounds

Sadly as of the time of writing, routing a container’s traffic makes it lose its ability to belong to a network. I knocked into this when I tried accessing the qBittorrent API. So for the sake of example, if you want to connect to qbittorrent, you need to route the traffic to the openvpn-client container at port 8000 which we specified earlier to be the webui port of qbittorrent.