nixpkgs/nixos/modules/config/fanout.nix
2023-10-21 17:31:14 -03:00

50 lines
1.3 KiB
Nix

{ config, lib, pkgs, ... }:
let
cfg = config.services.fanout;
mknodCmds = n: lib.lists.imap0 (i: s:
"mknod /dev/fanout${builtins.toString i} c $MAJOR ${builtins.toString i}"
) (lib.lists.replicate n "");
in
{
options.services.fanout = {
enable = lib.mkEnableOption (lib.mdDoc "fanout");
fanoutDevices = lib.mkOption {
type = lib.types.int;
default = 1;
description = "Number of /dev/fanout devices";
};
bufferSize = lib.mkOption {
type = lib.types.int;
default = 16384;
description = "Size of /dev/fanout buffer in bytes";
};
};
config = lib.mkIf cfg.enable {
boot.extraModulePackages = [ config.boot.kernelPackages.fanout.out ];
boot.kernelModules = [ "fanout" ];
boot.extraModprobeConfig = ''
options fanout buffersize=${builtins.toString cfg.bufferSize}
'';
systemd.services.fanout = {
description = "Bring up /dev/fanout devices";
script = ''
MAJOR=$(${pkgs.gnugrep}/bin/grep fanout /proc/devices | ${pkgs.gawk}/bin/awk '{print $1}')
${lib.strings.concatLines (mknodCmds cfg.fanoutDevices)}
'';
wantedBy = [ "multi-user.target" ];
serviceConfig = {
Type = "oneshot";
User = "root";
RemainAfterExit = "yes";
Restart = "no";
};
};
};
}