extip-svr - return requester's external IP via DNS

Companion server to https://github.com/hrbrmstr/extip.

Barring something bad happening to the remote host, you can test it out by doing:

dig myip.is @ip.rudis.net

It works for A, AAAA, and TXT. Safest bet is to use the TXT since it'll handle either IPv4 or IPv6.

dig myip.is TXT @ip.rudis.net

Installation

go install -ldflags "-s -w" github.com/hrbrmstr/extip-svr@latest

Usage

You can configure the server to bind to a particular port and use a TLD different than the default is. via flags or environment variables.

$ ./extip-svr --help
Usage: extip-svr [--port PORT] [--tld TLD] [--quiet]

Options:
  --port PORT, -p PORT   bind port [default: 53, env: EXTIP_PORT]
  --tld TLD, -t TLD      TLD to handle [default: is., env: EXTIP_TLD]
  --quiet, -q            Disable log messages
  --help, -h             display this help and exit

Disabling The systemd Stub Resolver

https://web.archive.org/web/20201203073829/https://www.turek.dev/posts/disable-systemd-resolved-cleanly/