Transmission WebUI 409 in Docker Container
<p>So, I've set up a docker container on my server host to act as a transmission-daemon seedbox. I installed openssh and transmission-daemon on the official Ubuntu 14.04 container. I forwarded port 9091 on the container to the host so I could access the container remotely, and I set up transmission-daemon with the following settings.json file:</p>

<pre><code>{
    "alt-speed-down": 50,
    "alt-speed-enabled": false,
    "alt-speed-time-begin": 540,
    "alt-speed-time-day": 127,
    "alt-speed-time-enabled": false,
    "alt-speed-time-end": 1020,
    "alt-speed-up": 50,
    "bind-address-ipv4": "0.0.0.0",
    "bind-address-ipv6": "::",
    "blocklist-enabled": false,
    "blocklist-url": "http://www.example.com/blocklist",
    "cache-size-mb": 4,
    "dht-enabled": true,
    "download-dir": "/root/transmission/complete",
    "download-limit": 100,
    "download-limit-enabled": 0,
    "download-queue-enabled": true,
    "download-queue-size": 5,
    "encryption": 1,
    "idle-seeding-limit": 30,
    "idle-seeding-limit-enabled": false,
    "incomplete-dir": "/root/transmission/incomplete",
    "incomplete-dir-enabled": true,
    "lpd-enabled": false,
    "max-peers-global": 200,
    "message-level": 2,
    "peer-congestion-algorithm": "",
    "peer-id-ttl-hours": 6,
    "peer-limit-global": 200,
    "peer-limit-per-torrent": 50,
    "peer-port": 51413,
    "peer-port-random-high": 65535,
    "peer-port-random-low": 49152,
    "peer-port-random-on-start": false,
    "peer-socket-tos": "default",
    "pex-enabled": true,
    "port-forwarding-enabled": false,
    "preallocation": 1,
    "prefetch-enabled": 1,
    "queue-stalled-enabled": true,
    "queue-stalled-minutes": 30,
    "ratio-limit": 2,
    "ratio-limit-enabled": false,
    "rename-partial-files": true,
    "rpc-authentication-required": true,
    "rpc-bind-address": "0.0.0.0",
    "rpc-enabled": true,
    "rpc-password": "{0477ada0ba97374d44fc4e78a5328dc32107ed26yYyN9qwZ",
    "rpc-port": 9091,
    "rpc-url": "/transmission/",
    "rpc-username": "transmission",
    "rpc-whitelist": "*.*.*.*",
    "rpc-whitelist-enabled": false,
    "scrape-paused-torrents-enabled": true,
    "script-torrent-done-enabled": false,
    "script-torrent-done-filename": "",
    "seed-queue-enabled": false,
    "seed-queue-size": 10,
    "speed-limit-down": 100,
    "speed-limit-down-enabled": false,
    "speed-limit-up": 100,
    "speed-limit-up-enabled": false,
    "start-added-torrents": true,
    "trash-original-torrent-files": false,
    "umask": 2,
    "upload-limit": 100,
    "upload-limit-enabled": 0,
    "upload-slots-per-torrent": 14,
    "utp-enabled": true
}
</code></pre>

<p>Whenever I connect to the server via <a href="http://ip_addr:9091/transmission/web/">http://ip_addr:9091/transmission/web/</a> or <a href="http://ip_addr:9091/transmission/">http://ip_addr:9091/transmission/</a> I get the following error:</p>

<blockquote>
  <p>409: Conflict</p>
  
  <p>Your request had an invalid session-id header.</p>
  
  <p>To fix this, follow these steps:</p>
  
  <p>When reading a response, get its X-Transmission-Session-Id header and
  remember it Add the updated header to your outgoing requests When you
  get this 409 error message, resend your request with the updated
  header This requirement has been added to help prevent CSRF attacks.</p>
  
  <p>X-Transmission-Session-Id:
  ulkx30bOoRTIw1yu4s0GCvUAGY6VFY844Iag3f8sfYtZjbRm</p>
</blockquote>

<p>Any ideas what I can do to solve this? Thanks!</p>