Add a module for setting sysctl parameters

This adds an option ‘boot.kernel.sysctl’ and generates a file
/etc/sysctl/nixos.conf read by systemd-sysctl.service.
This commit is contained in:
Eelco Dolstra 2013-03-02 19:53:48 +01:00
parent ec2378f07b
commit 080bf5614f
2 changed files with 59 additions and 0 deletions

58
modules/config/sysctl.nix Normal file
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@ -0,0 +1,58 @@
{ config, pkgs, ... }:
with pkgs.lib;
let
sysctlOption = mkOptionType {
name = "sysctl option value";
check = x: builtins.isBool x || builtins.isString x || builtins.isInt x;
merge = xs: last xs; # FIXME: hacky way to allow overriding in configuration.nix.
};
in
{
options = {
boot.kernel.sysctl = mkOption {
default = {};
example = {
"net.ipv4.tcp_syncookies" = false;
"vm.swappiness" = 60;
};
type = types.attrsOf sysctlOption;
description = ''
Runtime parameters of the Linux kernel, as set by
<citerefentry><refentrytitle>sysctl</refentrytitle>
<manvolnum>8</manvolnum></citerefentry>. Note that sysctl
parameters names must be enclosed in quotes
(e.g. <literal>"vm.swappiness"</literal> instead of
<literal>vm.swappiness</literal>). The value of each parameter
may be a string, integer or Boolean.
'';
};
};
config = {
environment.etc."sysctl.d/nixos.conf".text =
concatStrings (mapAttrsToList (n: v: "${n}=${if v == false then "0" else toString v}\n") config.boot.kernel.sysctl);
systemd.services.systemd-sysctl =
{ description = "Apply Kernel Variables";
before = [ "sysinit.target" "shutdown.target" ];
wantedBy = [ "sysinit.target" "multi-user.target" ];
restartTriggers = [ config.environment.etc."sysctl.d/nixos.conf".source ];
serviceConfig = {
Type = "oneshot";
RemainAfterExit = true;
ExecStart = "${config.systemd.package}/lib/systemd/systemd-sysctl";
};
};
};
}

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@ -10,6 +10,7 @@
./config/pulseaudio.nix
./config/shells.nix
./config/swap.nix
./config/sysctl.nix
./config/system-path.nix
./config/timezone.nix
./config/unix-odbc-drivers.nix