Home Assistant is a home automation platform written in Python, with extensive support for 3rd-party home-automation platforms including Xaomi, Phillips Hue, and a bazillion others.
Have you tried connecting any services which require local network access/service discovery? I wasn’t able to connect to my Philips Hue bridge using this compose file because the Hass container–being in that 172.16.13.0/24 internal network–isn’t seeing the broadcasts from the Hue bridge in my physical network when I push the button on the bridge. I was able to get this working using a MacVLAN, but it’s a bit clumsy, and I’d prefer not to use MacVLANs if I don’t have to.
Sadly, I’ve not. I had some sort of hacky solution for a time based on pipework, but in the end it just wasn’t a good fit for a swarm. I moved my hassio instance onto a raspberry pi for a while, but that turned out to be underpowered for what I wanted, so it’s now a standalone proxmox VM!
Is it possible to just run the homeassistant container with net=host?
Not in a swarm. If you want to use homeassistant in a swarm right now, you can use macvlan if it works for you, or use other reporting mechanisms that don’t rely on broadcast like MQTT brokers.