Transmission

This part of the tutorial will demonstrate how to install and configure an existing web application.

Using Ansible Roles

Unlike with the webserver from the previous example we will create a custom configuration, so instead of littering our top level directory with yet more playbooks and templates we will configure this instance using a role.

Let’s first create the required structure:

mkdir -p roles/transmission/tasks
mkdir -p roles/transmission/templates
mkdir -p roles/transmission/handlers

Populate them with a settings template in roles/transmission/templates/settings.json:

{
    "alt-speed-up": 50,
    "alt-speed-down": 200,
    "speed-limit-down": 5000,
    "speed-limit-down-enabled": true,
    "speed-limit-up": 100,
    "speed-limit-up-enabled": true,
    "start-added-torrents": true,
    "trash-original-torrent-files": true,
    "watch-dir": "{{download_dir}}",
    "watch-dir-enabled": true,
    "rpc-whitelist":  "127.0.0.*,10.0.*.*",
    "ratio-limit": 1.25,
    "ratio-limit-enabled": true
}

And in roles/transmission/handlers/main.yml:

---
- name: restart transmission
  service: name=transmission state=restarted

And finally in roles/transmission/tasks/main.yml:

- name: Ensure helper packages are installed
  pkgng: name={{ item }} state=present
  with_items:
  - transmission-daemon
  - transmission-web
- name: Setup transmission to start on boot
  service: name=transmission enabled=yes
- name: Configure transmission
  template: src=settings.json dest=/usr/local/etc/transmission/home/settings.json backup=yes owner=transmission
  notify:
    - restart transmission

The above tasks should look pretty familiar by now:

• install the required packages (this time it’s more than one and we demonstrate the with_items method)
• enable it in rc.conf
• Finally, as a new technique we upload a settings file as a template and…
• … use ansible’s handlers to make sure that the service is reloaded every time we change its settings.

Exercise One

Publish the transmission daemon’s web UI at http://192.168.56.100/transmission.

Note

Proxying to transmission can be a bit finicky as it requires certain CRSF protection headers, so here’s a small spoiler/hint.

This is the required nginx configuration to proxy to transmission:

location /transmission {
    proxy_http_version  1.1;
    proxy_set_header    Connection "";
    proxy_pass_header   X-Transmission-Session-Id;
    proxy_pass          http://transmissionweb;
    proxy_redirect      off;
    proxy_buffering     off;
    proxy_set_header    Host            $host;
    proxy_set_header    X-Real-IP       $remote_addr;
}

Exercise Two

Publish the downloads directory via nginx so users can download finished torrents from http://192.168.56.100/downloads.

Do this by configuring an additional jail that has read-only access to the download directory and publishes using its own nginx which is then targetted by the webserver jail.