{ config, lib, pkgs, ... }: with lib; let cfg = config.services.openvpn; inherit (pkgs) openvpn; makeOpenVPNJob = cfg: name: let path = makeBinPath (getAttr "openvpn-${name}" config.systemd.services).path; upScript = '' export PATH=${path} # For convenience in client scripts, extract the remote domain # name and name server. for var in ''${!foreign_option_*}; do x=(''${!var}) if [ "''${x[0]}" = dhcp-option ]; then if [ "''${x[1]}" = DOMAIN ]; then domain="''${x[2]}" elif [ "''${x[1]}" = DNS ]; then nameserver="''${x[2]}" fi fi done ${cfg.up} ${optionalString cfg.updateResolvConf "${pkgs.update-resolv-conf}/libexec/openvpn/update-resolv-conf"} ''; downScript = '' export PATH=${path} ${optionalString cfg.updateResolvConf "${pkgs.update-resolv-conf}/libexec/openvpn/update-resolv-conf"} ${cfg.down} ''; configFile = pkgs.writeText "openvpn-config-${name}" '' errors-to-stderr ${optionalString (cfg.up != "" || cfg.down != "" || cfg.updateResolvConf) "script-security 2"} ${cfg.config} ${optionalString (cfg.up != "" || cfg.updateResolvConf) "up ${pkgs.writeShellScript "openvpn-${name}-up" upScript}"} ${optionalString (cfg.down != "" || cfg.updateResolvConf) "down ${pkgs.writeShellScript "openvpn-${name}-down" downScript}"} ${optionalString (cfg.authUserPass != null) "auth-user-pass ${pkgs.writeText "openvpn-credentials-${name}" '' ${cfg.authUserPass.username} ${cfg.authUserPass.password} ''}"} ''; in { description = "OpenVPN instance ‘${name}’"; wantedBy = optional cfg.autoStart "multi-user.target"; after = [ "network.target" ]; path = [ pkgs.iptables pkgs.iproute2 pkgs.nettools ]; serviceConfig.ExecStart = "@${openvpn}/sbin/openvpn openvpn --suppress-timestamps --config ${configFile}"; serviceConfig.Restart = "always"; serviceConfig.Type = "notify"; }; restartService = optionalAttrs cfg.restartAfterSleep { openvpn-restart = { wantedBy = [ "sleep.target" ]; path = [ pkgs.procps ]; script = "pkill --signal SIGHUP --exact openvpn"; #SIGHUP makes openvpn process to self-exit and then it got restarted by systemd because of Restart=always description = "Sends a signal to OpenVPN process to trigger a restart after return from sleep"; }; }; in { imports = [ (mkRemovedOptionModule [ "services" "openvpn" "enable" ] "") ]; ###### interface options = { services.openvpn.servers = mkOption { default = { }; example = literalExpression '' { server = { config = ''' # Simplest server configuration: https://community.openvpn.net/openvpn/wiki/StaticKeyMiniHowto # server : dev tun ifconfig 10.8.0.1 10.8.0.2 secret /root/static.key '''; up = "ip route add ..."; down = "ip route del ..."; }; client = { config = ''' client remote vpn.example.org dev tun proto tcp-client port 8080 ca /root/.vpn/ca.crt cert /root/.vpn/alice.crt key /root/.vpn/alice.key '''; up = "echo nameserver $nameserver | ''${pkgs.openresolv}/sbin/resolvconf -m 0 -a $dev"; down = "''${pkgs.openresolv}/sbin/resolvconf -d $dev"; }; } ''; description = lib.mdDoc '' Each attribute of this option defines a systemd service that runs an OpenVPN instance. These can be OpenVPN servers or clients. The name of each systemd service is `openvpn-«name».service`, where «name» is the corresponding attribute name. ''; type = with types; attrsOf (submodule { options = { config = mkOption { type = types.lines; description = lib.mdDoc '' Configuration of this OpenVPN instance. See {manpage}`openvpn(8)` for details. To import an external config file, use the following definition: `config = "config /path/to/config.ovpn"` ''; }; up = mkOption { default = ""; type = types.lines; description = lib.mdDoc '' Shell commands executed when the instance is starting. ''; }; down = mkOption { default = ""; type = types.lines; description = lib.mdDoc '' Shell commands executed when the instance is shutting down. ''; }; autoStart = mkOption { default = true; type = types.bool; description = lib.mdDoc "Whether this OpenVPN instance should be started automatically."; }; updateResolvConf = mkOption { default = false; type = types.bool; description = lib.mdDoc '' Use the script from the update-resolv-conf package to automatically update resolv.conf with the DNS information provided by openvpn. The script will be run after the "up" commands and before the "down" commands. ''; }; authUserPass = mkOption { default = null; description = lib.mdDoc '' This option can be used to store the username / password credentials with the "auth-user-pass" authentication method. WARNING: Using this option will put the credentials WORLD-READABLE in the Nix store! ''; type = types.nullOr (types.submodule { options = { username = mkOption { description = lib.mdDoc "The username to store inside the credentials file."; type = types.str; }; password = mkOption { description = lib.mdDoc "The password to store inside the credentials file."; type = types.str; }; }; }); }; }; }); }; services.openvpn.restartAfterSleep = mkOption { default = true; type = types.bool; description = lib.mdDoc "Whether OpenVPN client should be restarted after sleep."; }; }; ###### implementation config = mkIf (cfg.servers != { }) { systemd.services = (listToAttrs (mapAttrsFlatten (name: value: nameValuePair "openvpn-${name}" (makeOpenVPNJob value name)) cfg.servers)) // restartService; environment.systemPackages = [ openvpn ]; boot.kernelModules = [ "tun" ]; }; }