Listen for network (dis)connect events (API v1.22+)

[AHelper]

If a container's network config changes, docker-gen should trigger the generator.

• v1.20 and below don't support networks
• v1.21 supports networks but has no events for network config changing
• v1.22+ supports network events (and container update event, not sure what exactly triggers that)

Right now, v1.20+ needs either an interval, a restart of docker-gen, or a restart of the changed container.

[outdooracorn]

This feature would be really helpful for me. I'm wanting to use nginx-proxy with several different docker compose projects. Currently, the process would be:

• Start the nginx-proxy container
• Start one of the docker compose projects (docker compose up -d)
  • This triggers the config to be recreated, but due to the nginx-proxy container and the docker compose project containers not (yet) being on the same network it only results in # Cannot connect to network 'NAME_OF_NETWORK' of this container comments being created
• Attach the network created by docker compose to the nginx-proxy container (docker network connect ...)
• Restart the nginx-proxy container to force docker-gen to recreate and reload the config

I'm hoping to avoid the last step and think that docker-gen listening for changes to the nginx-proxy container would solve this. Starting the docker compose project before the nginx-proxy container isn't possible for me, as each project is created and destroyed at different times.

@buchdag, any chance of adding this feature?
Thanks