Local access "invalid certificate"

I have set up hassio on an rpi 3 (standard installation) with duckdns. Access via https to the public address works as expected, but when trying to connect to https://hassio.local:8123 I get a warning from the browser that the connection is not secure. Apparently that’s normal behavior.

I can live with that, except I also have a device that sends http post requests to node-red at https://hassio.local:1880 (which I’ve also added to hassio). This fails with “Certificate is invalid for given domain”. How can I set this up correctly?

Can you use the DuckDNS name internally?

If you can set custom DNS entries in your DNS server, just set one for your duckdns address to your local IP.

Yes, the DuckDNS url (e.g. https://myduck.duckdns.org) works from everywhere, including internally. Hence a DNS entry is not needed.

However, https://myduck.duckdns.org:1880 (node red) would require a firewall rule in the router to forward port 1880. I do not want to do this for security reasons (I cannot use a password on node red since the service I’m using to post to node red does not support authentication).

Hence I really need local access, either with a correct certificate (ideal), or without ssl. Once I installed the duckdns add-on, hassio appears to require all traffic to be encrypted (good), but then has this issue with invalid certificate when access locally (for services that are not exposed).

I think I understand now why this should work. My current router lacks the feature (ATT Uverse), but I want to upgrade it with a Pepwave Soho anyway, and then I should be able to do this.

BTW: there is also a dnsmasq add-on for hassio, so that would be another option.

Thanks for the suggestion!

Yes if you put in a new DNS server and did it there you can point the rest of your network there too.

Probably the simplest way is a reverse proxy like Caddy which is really easy to setup and will give you local access as well as access via your domain without opening any additional ports.