nixcfg/os/modules/wesher_service.nix
2022-04-21 23:00:43 +02:00

137 lines
4.7 KiB
Nix

{ config, lib, pkgs, ... }:
with lib;
let
keysPath = "/var/lib/wesher/secrets";
cfg = config.services.wesher;
in {
options = with types; {
services.wesher = {
enable = mkEnableOption "wesher wireguard overlay mesh network manager";
package = mkOption {
type = package;
default = pkgs.wesher;
defaultText = literalExpression "pkgs.wesher";
description = "Wesher package to use.";
};
clusterKey = mkOption {
type = nullOr str;
default = null;
description = "shared key for cluster membership to use on first initialization, if no key was previously used by Wesher. Must be 32 bytes base64 encoded; will be generated if not provided. Setting this parameter value will not overwrite an existing cluster key; to do so please delete ${keysPath}";
};
bindAddr = mkOption {
type = nullOr str;
default = null;
description = "IP address to bind to for cluster membership (cannot be used with --bind-iface)";
};
bindIface = mkOption {
type = nullOr str;
default = null;
description = "Interface to bind to for cluster membership (cannot be used with --bind-addr)";
};
join = mkOption {
type = listOf str;
default = [];
description = "list of hostnames or IP addresses to existing cluster members; if not provided, will attempt resuming any known state or otherwise wait for further members";
};
clusterPort = mkOption {
type = port;
default = 7946;
description = "port used for membership gossip traffic (both TCP and UDP); must be the same accross cluster";
};
wireguardPort = mkOption {
type = port;
default = 51820;
description = "port used for wireguard traffic (UDP); must be the same accross cluster";
};
overlayNet = mkOption {
type = str;
default = "10.0.0.0/8";
description = "the network in which to allocate addresses for the overlay mesh network (CIDR format); smaller networks increase the chance of IP collision";
};
interface = mkOption {
type = str;
default = "wgoverlay";
description = "name of the wireguard interface to create and manage";
};
logLevel = mkOption {
type = str;
default = "warn";
description = "set the verbosity (one of debug/info/warn/error)";
};
};
};
config = mkIf cfg.enable (let binWesher = cfg.package + "/bin/wesher";
in {
system.activationScripts.wesher = if (cfg.clusterKey != null) then ''
if [ ! -e ${keysPath} ]
then
mkdir --mode=700 -p ${builtins.dirOf keysPath}
echo "WESHER_CLUSTER_KEY=${cfg.clusterKey}" > ${keysPath}
fi
'' else ''
if [ ! -e ${keysPath} ]
then
mkdir --mode=700 -p ${builtins.dirOf keysPath}
echo "WESHER_CLUSTER_KEY=$(head -c 32 /dev/urandom | base64)" > ${keysPath}
fi
'';
systemd.services.wesher = {
description = "wesher wireguard overlay mesh network manager";
bindsTo = [ "network-online.target" ];
after = [ "network-online.target" ];
wantedBy = [ "multi-user.target" ];
environment = {
WESHER_JOIN = builtins.concatStringsSep "," cfg.join;
WESHER_CLUSTER_PORT = builtins.toString cfg.clusterPort;
WESHER_WIREGUARD_PORT = builtins.toString cfg.wireguardPort;
WESHER_OVERLAY_NET = cfg.overlayNet;
WESHER_INTERFACE = cfg.interface;
WESHER_LOG_LEVEL = cfg.logLevel;
WESHER_NO_ETC_HOSTS = "true";
}
// (if (cfg.bindAddr != null) then { WESHER_BIND_ADDR = cfg.bindAddr; } else {})
// (if (cfg.bindIface != null) then { WESHER_BIND_IFACE = cfg.bindIface; } else {})
;
serviceConfig = {
ExecStart = "${binWesher}";
Restart = "always";
EnvironmentFile = keysPath;
User = "wesher";
DynamicUser = true;
StateDirectory = "wesher";
AmbientCapabilities = "CAP_NET_ADMIN CAP_NET_BIND_SERVICE";
CapabilityBoundingSet = "CAP_NET_ADMIN CAP_NET_BIND_SERVICE";
MemoryDenyWriteExecute = true;
ProtectControlGroups = true;
ProtectKernelModules = true;
ProtectKernelTunables = true;
RestrictAddressFamilies = "AF_UNIX AF_INET AF_INET6 AF_NETLINK";
RestrictNamespaces = true;
RestrictRealtime = true;
SystemCallArchitectures = "native";
SystemCallFilter = "~@clock @cpu-emulation @debug @keyring @module @mount @obsolete @raw-io @resources";
};
};
networking.firewall.allowedUDPPorts = mkIf cfg.enable [ cfg.clusterPort cfg.wireguardPort ];
networking.firewall.allowedTCPPorts = mkIf cfg.enable [ cfg.clusterPort ];
});
}