Carson is a lightweight, "real-time" web interface for rtorrent. It doesn't aim to resemble a full-fledged native UI similar to what µtorrent web ui or rutorrent do. Instead it tries to remain simple while being very flexible and interactive.

Carson leverages the latest web technologies such as HTML5 Canvas for beautiful download progress rendering and WebSockets for "real-time," persistent updates on the state of downloads. It's written as a lightweight Python Flask application serving a simple JSON API to an Angular.js front-end.

• highly interactive interface
  • drag-and-drop file uploads
  • easy and fast filtering of downloads
  • "real-time" updates on the state of downloads
• designed with multiple users in mind
  • lock system, used to avoid deleting things others are still interested in
  • simple role-based authorization system
  • invitation system

Pre-requisites are Python 2.x and rtorrent. It's probably also a good idea to do this all within a virtual environment with virtualenv. A webserver such as nginx is also recommended to serve static files. Auto-extraction requires 7z. All of these things should be available via your package manager.

$ git clone https://github.com/blaenk/carson.git
$ cd carson
$ virtualenv env
$ source env/bin/activate
$ pip install -r packages.txt
$ mv carson.conf{.example,}
$ python util.py init

Be sure to configure carson.conf. It has comments to explain every setting.

Of course rtorrent also needs configuration via ~/.rtorrent.rc:

# choose one; local preferable
#scgi_local = /where/you/want/rpc.socket
#scgi_port = localhost:5000

encoding_list = UTF-8

# to preserve state between launches
session = /where/you/want/session/

# where to store downloaded files
directory = /where/you/want/downloads/

# to allow large torrent uploads to go through
set_xmlrpc_size_limit = 5242880

# auto-extract (optional; requiers 7z program)
system.method.set_key = event.download.finished,extract,"execute=/path/to/carson/util.py,extract,$d.get_name="

# auto-erase files (optional)
system.method.set_key = event.download.erased,erase,"execute=/path/to/carson/util.py,erase,$d.get_name="

It's also preferable to use a webserver such as nginx to serve the static files:

client_max_body_size 10M;

location /sendfile/ {
  internal;
  alias /path/to/downloads/dir/;
}

location / {
  include uwsgi_params;
  uwsgi_pass unix:/tmp/uwsgi.sock;
}

location /assets/ {
  alias /path/to/carson/assets/;
  gzip_static on;
  expires max;
  add_header Cache-Control public;
}

A uwsgi.ini.example file is provided in the uwsgi/ directory with some default settings for the uwsgi server. Change the settings pertinent to your setup and remove the .example from the filename, then run as:

$ /path/to/carson/env/bin/uwsgi --ini /path/to/carson/uwsgi/uwsgi.ini

You can reload the server with:

$ kill -HUP `cat /tmp/uwsgi.pid`

You can kill the server with:

$ kill -QUIT `cat /tmp/uwsgi.pid`

A systemd service file is provided in the uwsgi/ folder which automates these tasks via systemd so that you can do:

$ sudo systemctl start uwsgi@youruser
$ sudo systemctl restart uwsgi@youruser
$ sudo systemctl stop uwsgi@youruser

There are other utility functions in util.py. One of them is prune which goes through the downloads and checks which have expired (no locks and older than 2 weeks) and removes them. Another is stale which goes through the top-level downloads directory to find any files that don't correspond to downloads inside rtorrent and removes them. These can be automated as cron jobs inside a crontab such as the following:

*/5 * * * * /path/to/carson/util.py prune
@daily /path/to/carson/util.py stale

There's also an add utility which loads the file pointed to by its argument. This is particularly useful for integration with autodownloader systems.

$ /path/to/carson/util.py add /tmp/somefile

Note: The util.py file has a hashbang pointing to python2 since on my system python is python 3. If your system doesn't have a python2 binary or symlink (check with which python2) then simply change the hashbang to python, which should be python 2.x (confirm with python -V).