Files
nix-files/hosts/modules/wg-home.nix
Colin 2684b3c1aa wg-home: re-enable keepalives
this should fix some of the flakiness i've seen when deploying moby?
2024-11-10 16:19:07 +00:00

111 lines
3.9 KiB
Nix

# wireguard VPN which allows my devices to talk to eachother even when on physically different LANs
# for wireguard docs, see:
# - <https://nixos.wiki/wiki/WireGuard>
# - <https://wiki.archlinux.org/title/WireGuard>
{ config, lib, pkgs, ... }:
let
cfg = config.sane.services.wg-home;
in
{
options = with lib; {
sane.services.wg-home.enable = mkEnableOption "wireguard VPN connecting my devices to eachother";
sane.services.wg-home.visibleToWan = mkOption {
type = types.bool;
default = false;
description = "whether to make this port visible on the WAN";
};
sane.services.wg-home.forwardToWan = mkOption {
type = types.bool;
default = false;
description = ''
whether to forward packets from wireguard clients to the WAN,
i.e. whether to act as a VPN exit node.
'';
};
sane.services.wg-home.routeThroughServo = mkOption {
type = types.bool;
default = true;
description = ''
whether to contact peers by routing through a stationary server.
should be true for all "clients", and false for that stationary server.
'';
};
sane.services.wg-home.ip = mkOption {
type = types.str;
};
};
config = lib.mkIf cfg.enable {
sops.secrets."wg-home.priv".owner = "systemd-network";
# wireguard VPN which allows everything on my domain to speak to each other even when
# not behind a shared LAN.
# also allows clients to proxy WAN traffic through it.
# this config defines both the endpoint (server) and client configs.
sane.ports.ports."51820" = lib.mkIf (!cfg.routeThroughServo) {
protocol = [ "udp" ];
visibleTo.lan = true;
visibleTo.wan = cfg.visibleToWan;
visibleTo.doof = cfg.visibleToWan;
description = "colin-wireguard";
};
# TODO: networking.wireguard is deprecated; remove
networking.wireguard = lib.mkIf (!cfg.routeThroughServo) {
enable = true;
interfaces.wg-home = {
listenPort = 51820;
privateKeyFile = "/run/secrets/wg-home.priv";
ips = [
"${cfg.ip}/24"
];
peers = let
all-peers = lib.mapAttrsToList (_: hostcfg: hostcfg.wg-home) config.sane.hosts.by-name;
peer-list = builtins.filter (p: p.ip != null && p.ip != cfg.ip && p.pubkey != null) all-peers;
# make separate peers to route each given host
in
builtins.map
({ ip, pubkey, endpoint }: assert endpoint == null; {
publicKey = pubkey;
allowedIPs = [
(if builtins.match ".*/.*" ip != null then ip else "${ip}/32")
];
# send keepalives every 25 seconds to keep NAT routes live.
# only need to do this from client -> server though, i think.
# persistentKeepalive = 25;
})
peer-list
;
} // (lib.optionalAttrs cfg.forwardToWan {
# documented here: <https://nixos.wiki/wiki/WireGuard#Server_setup_2>
postSetup = ''
${lib.getExe' pkgs.iptables "iptables"} -t nat -A POSTROUTING --source ${cfg.ip}/24 ! --destination ${cfg.ip}/24 -j MASQUERADE
'';
postShutdown = ''
${lib.getExe' pkgs.iptables "iptables"} -t nat -D POSTROUTING --source ${cfg.ip}/24 ! --destination ${cfg.ip}/24 -j MASQUERADE
'';
});
};
# plug into my VPN abstractions so that one may:
# - `sane-vpn up wg-home` to route all traffic through servo
# - `sane-vpn do wg-home THING` to route select traffic through servo
sane.vpn.wg-home = lib.mkIf cfg.routeThroughServo {
id = 51;
endpoint = config.sane.hosts.by-name."servo".wg-home.endpoint;
keepalive = true;
publicKey = config.sane.hosts.by-name."servo".wg-home.pubkey;
addrV4 = cfg.ip;
subnetV4 = "24";
dns = [
config.sane.hosts.by-name."servo".wg-home.ip
];
privateKeyFile = "/run/secrets/wg-home.priv";
};
};
}