Access HAOS remotely via Tailscale

This applies to the HAOS flavour of Home Assistant running on a Raspberry PI.

• Download and install the Tailscale community addon. The official addon is just for displaying info - not routing etc.
• Enable the addon and sign in to Tailscale.
• Go to Settings > Addons > Tailscale > Configuration and enable Show unused optional configuration options.
• Enable Tailscale Proxy and save.
• In configuration.yaml of your HA instance, add localhost as an allowed proxy source:

http:
      use_x_forwarded_for: true
      trusted_proxies:
        - 127.0.0.1

• Go to the Tailscale DNS admin console and pick a Tailnet name, enable MagicDNS and down at the bottom, enable HTTPS.
• Restart the Tailscale addon in HA.

You should now be able to access your HA instance via the Tailscale IP (100.x.x.x) or MagicDNS (your-ha-hostname.x.ts.net) on port 443 with a valid certificate.