Pure Python DNS server for developers
PyDevNS is a pure Python DNS server for developers. You know how you need a domain name to use for interacting with your app locally? Well, this is the tool for you.
I know what you’re thinking
Dude, what? I just put local.dev in my /etc/hosts file.
Well, that’s all well and good, but what about when you need local.dev and *.local.co?
There’s like a million things out there that do this. I could use dnsmasq, or one of the other 40 random Python “dev DNS” servers you probably stole your implementation from.
OK, dnsmasq kind of seems like overkill, but what about when you need local.dev or reallycoolprogrammer.local.dev to work from inside a docker container?
Well then I just make dnsmasq resolve it to my real IP instead of 127.0.0.1.
So you edit the config and restart dnsmasq every time you move from home, to the coffee shop, to the office, wherever…
That is kind of a pain, now that you mention it…
If you run devns with no arguments, the server will start, bind to 0.0.0.0 with a random port and try to discover a suitable IP address to use for resolving any incoming DNS requests. It literally does not care what domain you ask for, it always responds and always with the same IP, hopefully the IP address of your actual network interface (e.g. 192.168.1.52 or whatever). It tries to figure that out on its own, and I think it does a pretty good job of it.
But then how do I make DNS queries go to it, especially if it’s using a random port every time it runs?
Glad you asked. It’ll also try to write a file to /etc/resolver/dev, which if your OS supports such things, would tell it to send any DNS queries for domains ending it .dev to devns.
But wouldn’t I need to…
Run it with sudo to do that? Yeah probably, unless your system is insane and just lets anybody write to /etc all willy nilly, in which case you have bigger problems than getting local.dev to resolve to something sensible.
Run the server with a random port and auto-configured resolver for .dev resolving to a sensible, auto-detected IP address:
Listen on port 53535 without writing any resolver files:
devns --port 53535 --no-resolver
Respond with a specific IP every time instead of an auto discovered one:
sudo devns --address 172.24.3.1
Listen on port 53535, write config files for .dev and .local.co:
sudo devns --port 53535 --domains dev local.co
Bind to a random port on 127.0.0.1, and make a lot of noise:
sudo devns --host 127.0.0.1 -vvv
Here’s what devns --help gets you:
usage: devns [-h] [--verbose | --quiet] [--address ADDRESS] [--host HOST] [--port PORT] [--domains [DOMAIN [DOMAIN ...]]] [--resolver-dir DIRECTORY] [--no-resolver] optional arguments: -h, --help show this help message and exit --verbose, -v verbose output --quiet, -q quiet mode General: --address ADDRESS IP address to respond with Network: --host HOST address to listen on --port PORT port to listen on Resolver: --domains [DOMAIN [DOMAIN ...]] domains to create resolver files for --resolver-dir DIRECTORY where to put resolver files --no-resolver, -nr disable creating resolver files