Shell to host os?

It seems that Terminal & SSH both shell into the HA docker container.
I want to configure the base system; how do I access the host OS?

Specifically; I want to configure some vlan network interfaces. I can’t find anywhere inside HA to configure the network environment.
I also want to run another service on the host instance (TP-Link Omada controller).

Alternatively, I try and virtualise the Pi4, and run separate VM’s, but that doesn’t seem very appropriate on a pi.

You can’t.

No. They shell in a side container which has some mounted directories common with the HA container itself.

Every addon has it’s own container, no expeption afaik.

So, how do I reach the host OS?

Thanks.
Before I hit the host os; is there an official way to configure the host network interfaces?
How do I create some vlan interfaces officially?

As succinctly answered by Tinkerer, nothing you would do on the Host OS is supported / “official”.
It’s a “don’t touch” zone as far as support is concerned.

It’s all done in the UI, if you’re playing around on the host itself then:

  1. That’s not supported
  2. Your changes may be over-written without warning
  3. You may break things

Don’t do it.

So how to I manage the host network interfaces then? I see nothing in the UI relating to network management, except for choosing static/dynamic IP.

It looks like VLANs have to be managed with the ha network vlan command.