Improvements, suggestions & fixes are welcome!
Captive portals can be a pain. Here's an opinionated and no-doubt entirely imperfect guide to setting one up for a WiFi access point on Ubuntu (tested on 20+), utilising Network Manager, DNSMasq, HA Proxy and (optionally) Let's Encrypt for a secure, locally hosted landing page.
_Note: This setup was originally designed for an offline WLAN, providing access to a small number of locally hosted domains ... think the WiFi media portal on a flight or boat. If you are looking to provide internet access behind a captive portal then this guide won't get you all the way there. That said, many routers have this capability built in, as do any number of open source router firmware solutions. So you probably don't need to roll your own. If you'd like to try anyway, Ha Proxy Stick Tables would probably come in handy. Very happy to update the guide with any p
