nixpkgs/nixos/modules/system/boot/initrd-openvpn.nix
2021-10-04 12:47:20 +02:00

82 lines
2.1 KiB
Nix

{ config, lib, pkgs, ... }:
with lib;
let
cfg = config.boot.initrd.network.openvpn;
in
{
options = {
boot.initrd.network.openvpn.enable = mkOption {
type = types.bool;
default = false;
description = ''
Starts an OpenVPN client during initrd boot. It can be used to e.g.
remotely accessing the SSH service controlled by
<option>boot.initrd.network.ssh</option> or other network services
included. Service is killed when stage-1 boot is finished.
'';
};
boot.initrd.network.openvpn.configuration = mkOption {
type = types.path; # Same type as boot.initrd.secrets
description = ''
The configuration file for OpenVPN.
<warning>
<para>
Unless your bootloader supports initrd secrets, this configuration
is stored insecurely in the global Nix store.
</para>
</warning>
'';
example = literalExpression "./configuration.ovpn";
};
};
config = mkIf (config.boot.initrd.network.enable && cfg.enable) {
assertions = [
{
assertion = cfg.configuration != null;
message = "You should specify a configuration for initrd OpenVPN";
}
];
# Add kernel modules needed for OpenVPN
boot.initrd.kernelModules = [ "tun" "tap" ];
# Add openvpn and ip binaries to the initrd
# The shared libraries are required for DNS resolution
boot.initrd.extraUtilsCommands = ''
copy_bin_and_libs ${pkgs.openvpn}/bin/openvpn
copy_bin_and_libs ${pkgs.iproute2}/bin/ip
cp -pv ${pkgs.glibc}/lib/libresolv.so.2 $out/lib
cp -pv ${pkgs.glibc}/lib/libnss_dns.so.2 $out/lib
'';
boot.initrd.secrets = {
"/etc/initrd.ovpn" = cfg.configuration;
};
# openvpn --version would exit with 1 instead of 0
boot.initrd.extraUtilsCommandsTest = ''
$out/bin/openvpn --show-gateway
'';
# Add `iproute /bin/ip` to the config, to ensure that openvpn
# is able to set the routes
boot.initrd.network.postCommands = ''
(cat /etc/initrd.ovpn; echo -e '\niproute /bin/ip') | \
openvpn /dev/stdin &
'';
};
}