How to setup a minimal dns server which only resolves its own name?

General Discussion
1

I have a Raspi 3 A+ configured as WiFi access point, which has no internet connection. It only serves its own web application running on port 80.
The Raspi has a static IP address of 192.168.42.1, the first connected client gets 192.168.42.200 via dhcp.
The /etc/hosts file on the Raspi contains a line:
192.168.42.1 mybox
But I can’t access the web application using http://mybox on the client, only with http://192.168.42.1.
I assume I have to set up a minimal dns on the Raspi which only looks up in the hosts file, what is the best way to do that?

2

If you like to use an easy way, you can install one of our Adblocker PiHole or AdGuard Home. Both offer a web interface that can be used to configure your local DNS server. Maybe too heavy in your case but with less manual configuration steps needed.

Another option is to install a DNS server yourself. Could be Bind9 or dnsmasq. For both a lot of guides exist on the web.