nix-configs/modules/services/wireguard.nix
2025-07-29 03:02:25 +02:00

88 lines
2.9 KiB
Nix

{
pkgs,
lib,
config,
instanceConfigs,
instanceConfig,
...
}:
let
cfg = config.xyno.services.wireguard;
ula = "fd68:b6a4:36e4";
ulaPrefix = "${ula}:1337"; # /64 for normal vpn
monitoringUlaPrefix = "${ula}:2337"; # /64 for monitoring
# uses a hash digest as the host identifier
genUlaForHost =
prefix: hostName:
let
hostHash = builtins.hashString "sha512" hostName;
localParts = map (n: builtins.substring (n * 4) 4 hostHash) hostHash;
localPart = lib.concatStringsSep ":" localParts;
in
"${prefix}:${localPart}";
# peers list for networkd
wgPeers = map (
c:
(
(lib.optionals (lib.hasAttr c "publicHostname") {
# if peer is publicly on the internet
AllowedIPs =
(lib.optionals (c.wgServer) [
"${ulaPrefix}::/48" # all traffic in the ula shall be sent to the server
])
++ (lib.optionals (!c.wgServer) [
"${genUlaForHost ulaPrefix c.hostName}/128" # if a host is reachable but shouldn't play server, send only to the hosts ip
]);
Endpoint = "${c.publicHostname}:51820";
PersistentKeepalive = 25;
PublicKey = c.wgPubKey;
})
++ (lib.optionals (!(lib.hasAttr c "publicHostname") && instanceConfig.wgServer && (lib.hasAttr c "wgPubKey")) {
# if this is the server and the peer isn't reachable on the internet
AllowedIPs = [
"${genUlaForHost ulaPrefix c.hostName}/128"
"${genUlaForHost monitoringUlaPrefix c.hostName}/128"
];
PublicKey = c.wgPubKey;
# TODO: preshared keys
})
)
) instanceConfigs;
in
{
options.xyno.services.wireguard.enable = lib.mkEnableOption "enables wireguard";
options.xyno.services.wireguard.hostsDomain = lib.mkOpion { type = lib.types.str; default = "wg.hailsatan.eu"; };
config = lib.mkIf cfg.enable {
xyno.services.monitoring.ip = genUlaForHost monitoringUlaPrefix config.networking.hostName;
networking.hosts = lib.mapAttrs' (
n: v: {
name = "${v.hostName}.${cfg.hostsDomain}";
value = [ (genUlaForHost ulaPrefix v.hostName) ];
}
);
networking.firewall.allowedUDPPorts = lib.mkIf instanceConfig.wgServer [ 51820 ];
systemd.network.netdevs."wg0" = {
wireguardConfig = {
ListenPort = lib.mkIf instanceConfig.wgServer 51820;
PrivateKeyFile = config.sops.secrets.wg_privkey.path; # TODO
};
wireguardPeers = wgPeers;
};
systemd.network.networks."wg0" = {
matchConfig.Name = "wg0";
networkConfig = {
Description = "xyno wireguard";
};
address = [
"${(genUlaForHost ulaPrefix config.networking.hostName)}/128"
"${(genUlaForHost monitoringUlaPrefix config.networking.hostName)}/128"
];
};
sops.secrets.wg_privkey = {
reloadUnits = [ "systemd-networkd.service" ];
};
};
}