nixpkgs/nixos/modules/services/networking/dnscache.nix
2017-10-13 10:29:12 +01:00

90 lines
2.5 KiB
Nix

{ config, lib, pkgs, ... }:
with lib;
let
cfg = config.services.dnscache;
dnscache-root = pkgs.runCommand "dnscache-root" {} ''
mkdir -p $out/{servers,ip}
${concatMapStrings (ip: ''
echo > "$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 = "Whether to run the dnscache caching dns server";
};
ip = mkOption {
default = "0.0.0.0";
type = types.str;
description = "IP address on which to listen for connections";
};
clientIps = mkOption {
default = [ "127.0.0.1" ];
type = types.listOf types.str;
description = "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 = "table of {hostname: server} pairs to use as authoritative servers for hosts (and subhosts)";
example = {
"example.com" = ["8.8.8.8" "8.8.4.4"];
};
};
};
};
###### implementation
config = mkIf config.services.dnscache.enable {
environment.systemPackages = [ pkgs.djbdns ];
users.extraUsers.dnscache = {};
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/
exec ./run
'';
};
};
}