dnsreverseproxy

A very basic DNS reverse proxy

I started this project because I had a particular itch.
I wanted to create a middle DNS that could rewrite my home domain into Consul DNS queries while also routing the remaining queries to a regular DNS.
Can consul manage a different domain other than .consul? Of course, but I wanted to get rid of the .service part so I have something like gitlab.example.com that goes to the same IP as gitlab.service.consul.
I also played with prepared queries, but the documentation I've found online was not enough for me and I ended up doing this directly so I don't have a very complicated setup.
dnsdist is another candidate, but I preferred to do it in golang to learn the language.

Usage

COMMANDS:
   help, h  Shows a list of commands or help for one command

GLOBAL OPTIONS:
   --listen value, -l value                                                         Address and port to listen on (default: ":1053")
   --masqued-domain value, -m value                                                 Domain to be masqued (default: ".example.com.")
   --upstream-domain value, -u value                                                Upstream domain to be masqued (default: ".service.consul.")
   --upstream-domains value, --uds value [ --upstream-domains value, --uds value ]  Upstream domains to be resolved (default: "service.consul.", ".consul.")
   --upstream-special value, --uc value [ --upstream-special value, --uc value ]    Special upstream host:port (default: "localhost:8600")
   --upstream-normal value, --un value [ --upstream-normal value, --un value ]      Normal resolution upstream host:port (default: "1.1.1.1:53")
   --help, -h                                                                       show help

ToDo

Config file. https://cli.urfave.org/v2/examples/flags/#values-from-alternate-input-sources-yaml-toml-and-others
Debug mode.
Retry normal upstream.
Enable local DNS overrides.