3w ago

DHT dies in podman?

I'm trying to move over from transmission on my laptop to qbittorrent on my NAS. I have it running rootlessly in a podman container. I wanted the stats to show up on my heimdall webUI so I put both containers into the same network with a Network=heimdallnet line in their quadlets and fired them up again. It worked, except DHTs are dead and the qbittorrent stays firewalled.

After spending too much time on this issue, I asked chatgpt for advice. It suggested I do an iptables rule to allow for nat from the bridge network to the outside world. That did resolve the firewall status but DHTs stayed dead. I gave up and removed the Network=heimdallnet line.

I'm sure this is doable, but I'm not quite smart enough to understand what I did wrong.

3 comments

What does qBittorrent say when you load a public torrent and click the Trackers tab for that torrent? In a normal network - if these are enabled in qBittorrent itself and the network isn't blocking torrents/DHT traffic - you should see DHT / PeX / LSD listed as "Working".
I know nothing about podman but perhaps DHT status will be a clue to figuring out what's going on.
PS - If you need a test public torrent the Linux Mint downloads are useful https://www.linuxmint.com/edition.php?id=319
EDIT: Also when you start up qBittorrent try viewing the execution log (enabled under View / Log), one of the startup lines in the log is your DHT support that will tell you if it is enabled/disabled. I don't know if the log later shows anything else re: DHT issues but could be worth a look for that too.
- I put it back on heimdallnet and tried downloading fedora linux. Status is firewalled and theres no DHT but the download works and there are no errors in the log. I looked at an i2p torrent I was playing with too and its showing the trackers are non responsive now, but theres no error in the logs.
  I think I am not understanding how PublishPort= works in quadlets. That was enough to have it pass those ports to the container before I added the network= string in the quadlet. What is different now? Its like it passes the webUI port and not the others
  
  Status is firewalled and theres no DHT
  When you select the torrent in qBittorrent and click the Trackers tab does DHT display "working" ?
  Status is firewalled and theres no DHT but the download works and there are no errors in the log.
  I suspect you had it partially correct with your earlier test. One thing is that DHT works via UDP (from what I understand) while non-DHT torrents can be TCP or UDP. So I sort of suspect that you kind of had it half working with the iptables rule earlier but you only had it working for TCP, hence only TCP torrents get through which means no DHT and uTP torrenting.
  So your solution is one/both of
  Re-configure your iptables rule to allow both TCP and UDP if it wasn't already
  Play around with podman to get it to also publish the UDP port(s), not just TCP. According to this site podman only publishes TCP by default, there's some extra syntax for --publish to specify the protocol. Maybe you need to give it multiple publish flags so you can use both TCP and UDP on the same port(s), not too sure on that.
  https://ittavern.com/notes/podman-publish-udp-port-to-host/
  I looked at an i2p torrent I was playing with too and its showing the trackers are non responsive now, but theres no error in the logs.
  I2P is a very different configuration, best not to compare that to regular clearnet torrenting. qBittorrent doesn't suport DHT over I2P so you'll never see DHT working in that configuration.