App to DDNS with API for Local HTTPS Certificate

by Rian

I’m still in the process of writing up the Caddy + DuckDNS post, but I thought to make a separate post anyway what DDNS is and why I am writing about DuckDNS for the particular home lab setup. DDNS is often used for home or small office environment, when the IP address to the said network is not fixed. ISP usually ask extra for fixed IP address. DDNS effectively keeps the record of your machine’s public IP, thereby connecting to the said DDNS domain would lead back to home.

The problem isn’t exactly the DDNS. I had used different services before, and majority of them work fine. Some of them do have mandatory “renewal” to reserve a spot (i.e. login every month to keep the domain active), which makes it less appealing for ‘set it and forget it’ practice, but it still works. The problem is the certificate. For majority of my projects, they have some form of web UI frontend. However, browsers, even if it’s accessing local network IP address, does not like unprotected addresses.

This is where DuckDNS comes in. DuckDNS is free with its API exposed that solves the problem that I just outlined. In my current setup, DuckDNS is resolving my personal domain to a local IP address. What I actually gain from the service would be: access to subdomains, fixing certificate issue, and not needing to login or pay for DDNS.

Again, I’ll do more thorough write up on the subject as how-to post. A lot of the actual work is done on the Caddy side, albeit it is possible thanks to DuckDNS’ API. There are other services, paid or otherwise, out there too. I only happen to find out about DuckDNS only because it is free and has a Caddy plugin.