Having a BitTorrent seedbox is convenient in many ways. Few days ago, I needed to download something (totally legal!) using BitTorrent, but I don’t want to open my laptop 24/7 for seeding. Since I already have a dokku server up and running, I can just set up a BitTorrent seedbox using rtorrent and ruTorrent

The method is to use dokku’s image tag deployment to set up a new app. But first I need to have a docker image for rTorrent and ruTorrent. Fortunately, there is one Kerwood/Rtorrent-LXC, so I am not going to repeat myselft.

First I need to create a new app

ssh dokku@tannguyen.org apps:create torrent

Then, I need to pull the Rtorrent-LXC image from docker hub into my local machine

docker pull kerwood/rtorrent-lxc

Then, retag it to follow dokku’s conventions

docker tag kerwood/rtorrent-lxc dokku/torrent:v1

However, this image is stored in my local machine, I need to push it to the dokku server before I can do any deployment

docker save dokku/torrent:v1 | bzip2 | ssh root@tannguyen.org "bunzip2 | docker load"

With that I have the image loaded to my dokku server, now the actual deployment can happen

ssh dokku@tannguyen.org tags:deploy torrent v1

It will take some minutes, and after that everything is (almost) ready. There are few things I need to take care afterward

Port mapping

The default port mapping is http:80:5000 which means to map port 5000 of the container to port 80 in the nginx virtual host, but according to Rtorrent-LXC, it runs rutorrent on port 80. So I need to change the port mapping from 5000 to 80

ssh dokku@tannguyen.org config:set torrent DOKKU_PROXY_PORT_MAP=http:80:80


By default, the deployed app can be accessed by anyone. And I don’t really want to allow that. There is a plugin to provide basic access authentication for dokku apps, dokku-secure-apps.

I need to install the plugin first, and it can only be done using a user with sudo permission. But I am going to use root because I can

ssh root@tannguyen.org dokku plugin:install https://github.com/matto1990/dokku-secure-apps.git secure-apps

The next step is to create an identity

ssh dokku@tannguyen.org secure:set torrent my-user super-duper-strong-password
ssh dokku@tannguyen.org secure:enable torrent

Get the downloaded files

Downloaded files are stored within the docker container, I need to mount the download directory to a directory in the host in order to access the downloaded files. Dokku comes with a plugin docker-options to make it easy to specify docker options

ssh dokku@tannguyen.org docker-options:add torrent run "-v /home/dokku/torrent/downloads:/downloads"
ssh dokku@tannguyen.org docker-options:add torrent deploy "-v /home/dokku/torrent/downloads:/downloads"

Note that /home/dokku/torrent/downloads must be created beforehand and must be owned by dokku:dokku.

Some problems

  • Whenever I re-deploy the app, everything I have downloaded so far is gone. It’s not a big problem because for this app, I don’t think I will need to re-deploy it

  • rTorrent occasionally crashes. And when it happens I need to go inside the docker container to start rtorrent again. I am not sure what causes it yet, only saw it once since the deployment.

Happy torrenting!!!