lets-nginx does not pick up changes to container IPs in a swarm

[finestructure]

I've had some issues with lets-nginx not picking up container IP changes when they were restarted in a docker swarm with an overlay network. I've described the problem in more detail in this stackoverflow post and I believe I've also come up with a solution:

If I update the vhost.sample.conf as follows:

    ...
    location / {
      resolver 127.0.0.11 ipv6=off valid=10s;
      set $upstream http://${UPSTREAM};
      proxy_pass $upstream;
      proxy_set_header Host $host;
      ...

changes seem to be picked up. Note that 127.0.0.11 is the resolver in a swarm, which probably makes this unusable as an update to the default file.

I'm leaving this here to see if there's a sensible default to be derived from this that would work both in a single host context as well as a swarm.