How to use OpenBSD's Packet Filter and Unbound to build a zero-trust network sandbox that neutralizes Smart TV telemetry—and inadvertently speeds up streaming across your entire home network.

This is how I set up a readonly OpenBSD 6.8 system.
The system is a router running off an SD card. I want to minimise wear on the SD card, and I want the system to come up clean after a power failure. For times when I need to make a quick tweak, I can still go read-write temporarily.
This is unfortunately not a supported OpenBSD setup, and small tweak to /etc/rc is necessary.

httpd is the OpenBSD built-in Webserver. It has support for FastCGI which is a protocol that allows Web servers to execute external programs through a FastCGI Server. In OpenBSD, the FastCGI Server is called slowcgi and also is in the default installation. So it is possible to build a dynamic website or API without installing additional packages.