ESPHome Builder running in docker and device discovery

ESPHome
1

I moved the ESPHome Device Builder off to a faster machine running in docker. Took me a few minutes to realize that mDNS announcements were not getting to the container.

I figured out two options to get the discovery working, but it left me with a few questions (as I’m no Docker experts at all).

The two options that worked are to either run the container in network_mode: host or to set enable-reflector=yes in /etc/avahi/avahi-daemon.conf.

Questions:

  1. Is one option from above better than the other, and why?

  2. Is there another (or better) way to get mDNS into the container, e.g. something in the docker-compose.yaml file?

  3. Oddly, I have ESPHOME_DASHBOARD_USE_PING=false in my docker-compose (I blindly copied from my past notes), but with that false AND no mDNS I’m confused how the Device Builder found any of my on-line devices. Does it work via by looking at the yaml files’ configured host or ip? I guess I’m not understanding how it finds devices.

  4. Finally, how does the ESPHome device builder determine if a device has already been adopted? I ask because when testing I tried just hiding a device’s config.yaml, but that didn’t make it show up as discoverable.

Thanks.

here's the docker-compose.yaml I'm using: 
services:
  esphome:
    image: ghcr.io/esphome/esphome:latest
    container_name: esphome
    environment:
      - PUID=1000
      - PGID=1000
      # How does this being false still find devices when mDNS is not available?
      - ESPHOME_DASHBOARD_USE_PING=false
      - TZ=America/Los_Angeles
    volumes:
      - ./config:/config
    ports:
      - 6052:6052
    restart: unless-stopped

    # Attempt to get mdns down into this container
    # This puts the container on the host network, so "ports"
    # above doesn't do anything.
    # network_mode: host