nixpkgs/nixos/modules/services/networking/dnscache.nix
pennae 2e751c0772 treewide: automatically md-convert option descriptions
the conversion procedure is simple:

 - find all things that look like options, ie calls to either `mkOption`
   or `lib.mkOption` that take an attrset. remember the attrset as the
   option
 - for all options, find a `description` attribute who's value is not a
   call to `mdDoc` or `lib.mdDoc`
 - textually convert the entire value of the attribute to MD with a few
   simple regexes (the set from mdize-module.sh)
 - if the change produced a change in the manual output, discard
 - if the change kept the manual unchanged, add some text to the
   description to make sure we've actually found an option. if the
   manual changes this time, keep the converted description

this procedure converts 80% of nixos options to markdown. around 2000
options remain to be inspected, but most of those fail the "does not
change the manual output check": currently the MD conversion process
does not faithfully convert docbook tags like <code> and <package>, so
any option using such tags will not be converted at all.
2022-07-30 15:16:34 +02:00

108 lines
3.1 KiB
Nix

{ config, lib, pkgs, ... }:
with lib;
let
cfg = config.services.dnscache;
dnscache-root = pkgs.runCommand "dnscache-root" { preferLocalBuild = true; } ''
mkdir -p $out/{servers,ip}
${concatMapStrings (ip: ''
touch "$out/ip/"${lib.escapeShellArg ip}
'') cfg.clientIps}
${concatStrings (mapAttrsToList (host: ips: ''
${concatMapStrings (ip: ''
echo ${lib.escapeShellArg ip} >> "$out/servers/"${lib.escapeShellArg host}
'') ips}
'') cfg.domainServers)}
# if a list of root servers was not provided in config, copy it
# over. (this is also done by dnscache-conf, but we 'rm -rf
# /var/lib/dnscache/root' below & replace it wholesale with this,
# so we have to ensure servers/@ exists ourselves.)
if [ ! -e $out/servers/@ ]; then
# symlink does not work here, due chroot
cp ${pkgs.djbdns}/etc/dnsroots.global $out/servers/@;
fi
'';
in {
###### interface
options = {
services.dnscache = {
enable = mkOption {
default = false;
type = types.bool;
description = lib.mdDoc "Whether to run the dnscache caching dns server.";
};
ip = mkOption {
default = "0.0.0.0";
type = types.str;
description = lib.mdDoc "IP address on which to listen for connections.";
};
clientIps = mkOption {
default = [ "127.0.0.1" ];
type = types.listOf types.str;
description = lib.mdDoc "Client IP addresses (or prefixes) from which to accept connections.";
example = ["192.168" "172.23.75.82"];
};
domainServers = mkOption {
default = { };
type = types.attrsOf (types.listOf types.str);
description = lib.mdDoc ''
Table of {hostname: server} pairs to use as authoritative servers for hosts (and subhosts).
If entry for @ is not specified predefined list of root servers is used.
'';
example = literalExpression ''
{
"@" = ["8.8.8.8" "8.8.4.4"];
"example.com" = ["192.168.100.100"];
}
'';
};
forwardOnly = mkOption {
default = false;
type = types.bool;
description = lib.mdDoc ''
Whether to treat root servers (for @) as caching
servers, requesting addresses the same way a client does. This is
needed if you want to use e.g. Google DNS as your upstream DNS.
'';
};
};
};
###### implementation
config = mkIf config.services.dnscache.enable {
environment.systemPackages = [ pkgs.djbdns ];
users.users.dnscache.isSystemUser = true;
systemd.services.dnscache = {
description = "djbdns dnscache server";
wantedBy = [ "multi-user.target" ];
path = with pkgs; [ bash daemontools djbdns ];
preStart = ''
rm -rf /var/lib/dnscache
dnscache-conf dnscache dnscache /var/lib/dnscache ${config.services.dnscache.ip}
rm -rf /var/lib/dnscache/root
ln -sf ${dnscache-root} /var/lib/dnscache/root
'';
script = ''
cd /var/lib/dnscache/
${optionalString cfg.forwardOnly "export FORWARDONLY=1"}
exec ./run
'';
};
};
}