Private Internet Access OpenVPN - Transmission

This Docker container lets you run Transmission with WebUI while connecting to PIA VPN. It updates Transmission hourly with assigned open port from PIA. Please read the instructions below.

Run container from Docker registry

The container is available from the Docker registry and this is the simplest way to get it. To run the container use this command:

$ docker run --privileged  -d \
              -v /your/storage/path/:/data \
              -e "PIA_USERNAME=user" \
              -e "PIA_PASSWORD=pass" \
              -p 9091:9091 \
              haugene/transmission-openvpn

or you could optionally specify which vpn server to use by setting an environment variable to one of the ovpn configs avaliable in this folder.

$ docker run --privileged  -d \
              -v /your/storage/path/:/data \
              -e "PIA_USERNAME=user" \
              -e "PIA_PASSWORD=pass" \
              -p 9091:9091 \
              -e "OPEN_VPN_CONFIG=US West" \
              haugene/transmission-openvpn

As you can see, the container expects a data volume to be mounted. It is used for storing your downloads from Transmission. The container comes with a default Transmission settings.json file that expects the folders completed, incomplete, and watch to be present in /your/storage/path (aka /data). This is where Transmission will store your downloads, incomplete downloads and a watch directory to look for new .torrent files.

The only mandatory configuration is to set two environment variables for your PIA username and password. You must set the environment variables PIA_USERNAME and PIA_PASSWORD to your login credentials. The container will connect to the Private Internet Access VPN servers in Netherlands by default.

Required environment options

Variable	Function	Example
PIA_USERNAME	Your login username for PIA	PIA_USERNAME=asdf
PIA_PASSWORD	Your login password for PIA	PIA_PASSWORD=asdf

Network configuration options

Variable	Function	Example
OPEN_VPN_CONFIG	Sets the PIA endpoint to connect to.	OPEN_VPN_CONFIG=UK Southampton
RESOLV_OVERRIDE	The value of this variable will be written to /etc/resolv.conf.	RESOLV_OVERRIDE=nameserver 8.8.8.8\nnameserver 8.8.4.4\n

Transmission configuration options

You may override transmission options by setting the appropriate environment variable.

The environment variables are the same name as used in the transmission settings.json file and follow the format given in these examples:

Transmission variable name	Environment variable name
speed-limit-up	TRANSMISSION_SPEED_LIMIT_UP
speed-limit-up-enabled	TRANSMISSION_SPEED_LIMIT_UP_ENABLED
ratio-limit	TRANSMISSION_RATIO_LIMIT
ratio-limit-enabled	TRANSMISSION_RATIO_LIMIT_ENABLED

As you can see the variables are prefixed with TRANSMISSION_, the variable is capitalized, and - is converted to _.

PS: TRANSMISSION_BIND_ADDRESS_IPV4 will be overridden to the IP assigned to tunnel interface by PIA. This is to prevent leaking of the host IP.

Building the container yourself

To build this container, clone the repository and cd into it.

Build it:

$ cd /repo/location/docker-transmission-openvpn
$ docker build -t="docker-transmission-openvpn" .

Run it:

$ docker run --privileged  -d \
              -v /your/storage/path/:/data \
              -e "PIA_USERNAME=user" \
              -e "PIA_PASSWORD=pass" \
              -p 9091:9091 \
              docker-transmission-openvpn

As described in the "Run container from Docker registry" section, this will start a container with default settings. This means that you should have the folders "completed, incomplete and watch" in /your/storage/path, and pia-credentials.txt in /your/config/path.

Access the WebUI

But what's going on? My http://my-host:9091 isn't responding? This is because the VPN is active, and since docker is running in a different ip range than your client the response to your request will be treated as "non-local" traffic and therefore be routed out through the VPN interface.

How to fix this

There are several ways to fix this. You can pipe and do fancy iptables or ip route configurations on the host and in the Docker image. But I found that the simplest solution is just to proxy my traffic. Start a Nginx container like this:

$ docker run -d -v /path/to/nginx.conf:/etc/nginx/nginx.conf:ro -p 8080:8080 nginx

Where /path/to/nginx.conf has this content:

events {
  worker_connections 1024;
}

http {
  server {
    listen 8080;
    location / {
      proxy_pass http://host.ip.address.here:9091;
    }
  }
}

Your Transmission WebUI should now be avaliable at "your.host.ip.addr:8080/transmission/web/". Change the port in the docker run command if 8080 is not suitable for you.

What if I want to run the container interactively.

If you want do have access inside the container while running you have two choices. To have a look inside an already running container, use docker exec to get a terminal inside the container.

$ docker ps | grep transmission-openvpn | awk '{print $1}' // Prints container id
$ af4dd385916d
$ docker exec -it af4dd bash

If you want to start the container without it starting OpenVPN on boot, then run the image without daemonizing and use bash as entrypoint.

$ docker run --privileged -it transmission-openvpn bash

From there you can start the service yourself, or do whatever (probably developer-related) you came to do.

Controlling Transmission remotely

The container exposes /config as a volume. This is the directory where the supplied transmission and PIA credentials will be stored. If you have transmission authentication enabled and want scripts in another container to access and control the transmission-daemon, this can be a handy way to access the credentials. For example, another container may pause or restrict transmission speeds while the server is streaming video.