Dependant container stops functioning if NordLynx restarts

[dem0ngo]

Describe the bug

I'm new to routing a container through another one like this, but I have NordLynx set up and things work fine if I create it and the other container that depends on it at the same time. However if NordLynx ever restarts for any reason then the dependent container ceases to function. Even if I restart the dependent container it fails. I have to completely remove and recreate it in order for it to work again.

To Reproduce using docker-compose

  nordlynx:
    image: ghcr.io/bubuntux/nordlynx
    container_name: vpn
    cap_add:
      - NET_ADMIN 
    environment:
      - PRIVATE_KEY=
      - ALLOWED_IPS=0.0.0.0/1,128.0.0.0/1
      - NET_LOCAL=192.168.1.0/24
      - "POST_UP=ip -4 route add $$(wg | awk -F'[: ]' '/endpoint/ {print $$5}') via $$(ip route | awk '/default/ {print $$3}')"
      - "PRE_DOWN=ip -4 route del $$(route -n | awk '/255.255.255.255/ {print $$1}') via $$(ip route | awk '/default/ {print $$3}')"
    ports:
      - 8080:8080
      - 6881:6881
      - 6881:6881/udp
    sysctls:
      - net.ipv6.conf.all.disable_ipv6=1  # Recomended if using ipv4 only
  qbittorrent:
    image: lscr.io/linuxserver/qbittorrent:latest
    container_name: qbittorrent
    network_mode: service:nordlynx 
    depends_on:
      - nordlynx
    environment:
      - PUID=${PUID}
      - PGID=${PGID}
      - TZ=${TZ}
      - WEBUI_PORT=8080
    volumes:
      - ${DOCKERDIR}/qbittorrent1/config:/config 
      - ${DATADIR}/torrents:/data/torrents
    restart: unless-stopped

Expected behavior

If NordLynx restarts then the dependent container should continue to function like normal or be recreated automatically.

Logs

Nothing in the logs that I can find.

[infuze999]

I have had this particular problem for a long time, and I get around it by adding Healthchecks to the services that don't already have it, that depend on the vpn in the docker-compose file like this:

healthcheck:
 test: curl --fail http://google.com || exit 1
 interval: 10s
 timeout: 5s
 retries: 3

Then I run https://hub.docker.com/r/willfarrell/autoheal/ to restart unhealthy services automatically

[dem0ngo]

It sounds like this will only restart the containers, but like I mentioned my issue is that I have to recreate the container to get it to work. Will this workaround still fix that issue?

[infuze999]

Based on your description of the problem it sounds like the exact same problem I had, and the solution worked.
With the exception that if you automatically update VPN, it sometimes messes up and you have to manually restart everything. But only sometimes.

[dem0ngo]

Okay I got it up and from what I can tell its working. I stopped the NordLynx container, waited for the qBittorrent health check to take effect, restarted NordLynx, and then waited for autoheal to restart qBittorrent. Once I did that the webui was accessible like I hoped. Thanks for your help!

[dem0ngo]

I spoke too soon. If I recreate NordLynx then qBittorrent becomes unhealthy and autoheal gives this generic failure message

22-05-2022 13:05:45 Container /qbittorrent (c07fc6692b4a) found to be unhealthy - Restarting container now with 10s timeout
22-05-2022 13:05:45 Restarting container c07fc6692b4a failed

Is this the issue you were mentioning when the vpn auto-updates? Is this just expected behavior when one container depends on another one?

[infuze999]

Yes, it's as if docker no longer recognises it as the container others depend on if you edit docker-compose or update image.

[dem0ngo]

Hmm, well at least it fixed the issue for simple restarts or interruptions to the VPN container.

[ginodesilva]

This is not a NordLynx issue but a docker issue. What I've read is that there is no solution atm. People have created workarounds such as the autoheal suggested above but from what I'm understanding is that no definitive answer to this problem has been found.

[github-actions]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.