124 lines
3.5 KiB
Nix
124 lines
3.5 KiB
Nix
{ config, pkgs, utils, ... }:
|
||
|
||
with pkgs.lib;
|
||
with utils;
|
||
|
||
{
|
||
|
||
###### interface
|
||
|
||
options = {
|
||
|
||
swapDevices = mkOption {
|
||
default = [];
|
||
example = [
|
||
{ device = "/dev/hda7"; }
|
||
{ device = "/var/swapfile"; }
|
||
{ label = "bigswap"; }
|
||
];
|
||
description = ''
|
||
The swap devices and swap files. These must have been
|
||
initialised using <command>mkswap</command>. Each element
|
||
should be an attribute set specifying either the path of the
|
||
swap device or file (<literal>device</literal>) or the label
|
||
of the swap device (<literal>label</literal>, see
|
||
<command>mkswap -L</command>). Using a label is
|
||
recommended.
|
||
'';
|
||
|
||
type = types.listOf types.optionSet;
|
||
|
||
options = {config, options, ...}: {
|
||
|
||
options = {
|
||
|
||
device = mkOption {
|
||
example = "/dev/sda3";
|
||
type = types.uniq types.string;
|
||
description = "Path of the device.";
|
||
};
|
||
|
||
label = mkOption {
|
||
example = "swap";
|
||
type = types.uniq types.string;
|
||
description = ''
|
||
Label of the device. Can be used instead of <varname>device</varname>.
|
||
'';
|
||
};
|
||
|
||
size = mkOption {
|
||
default = null;
|
||
example = 2048;
|
||
type = types.nullOr types.int;
|
||
description = ''
|
||
If this option is set, ‘device’ is interpreted as the
|
||
path of a swapfile that will be created automatically
|
||
with the indicated size (in megabytes) if it doesn't
|
||
exist.
|
||
'';
|
||
};
|
||
|
||
priority = mkOption {
|
||
default = null;
|
||
example = 2048;
|
||
type = types.nullOr types.int;
|
||
description = ''
|
||
Specify the priority of the swap device. Priority is a value between 0 and 32767.
|
||
Higher numbers indicate higher priority.
|
||
null lets the kernel choose a priority, which will show up as a negative value.
|
||
'';
|
||
};
|
||
|
||
};
|
||
|
||
config = {
|
||
device =
|
||
if options.label.isDefined then
|
||
"/dev/disk/by-label/${config.label}"
|
||
else
|
||
mkNotdef;
|
||
};
|
||
|
||
};
|
||
|
||
};
|
||
|
||
};
|
||
|
||
config = mkIf ((length config.swapDevices) != 0) {
|
||
|
||
system.requiredKernelConfig = with config.lib.kernelConfig; [
|
||
(isYes "SWAP")
|
||
];
|
||
|
||
# Create missing swapfiles.
|
||
# FIXME: support changing the size of existing swapfiles.
|
||
systemd.services =
|
||
let
|
||
|
||
createSwapDevice = sw:
|
||
assert sw.device != "";
|
||
let device' = escapeSystemdPath sw.device; in
|
||
nameValuePair "mkswap-${escapeSystemdPath sw.device}"
|
||
{ description = "Initialisation of Swapfile ${sw.device}";
|
||
wantedBy = [ "${device'}.swap" ];
|
||
before = [ "${device'}.swap" ];
|
||
path = [ pkgs.utillinux ];
|
||
script =
|
||
''
|
||
if [ ! -e "${sw.device}" ]; then
|
||
fallocate -l ${toString sw.size}M "${sw.device}" ||
|
||
dd if=/dev/zero of="${sw.device}" bs=1M count=${toString sw.size}
|
||
mkswap ${sw.device}
|
||
fi
|
||
'';
|
||
unitConfig.RequiresMountsFor = [ "${dirOf sw.device}" ];
|
||
unitConfig.DefaultDependencies = false; # needed to prevent a cycle
|
||
serviceConfig.Type = "oneshot";
|
||
};
|
||
|
||
in listToAttrs (map createSwapDevice (filter (sw: sw.size != null) config.swapDevices));
|
||
|
||
};
|
||
|
||
}
|