selfhostblocks/modules/blocks/zfs.nix
2026-03-14 23:27:23 +01:00

129 lines
4 KiB
Nix

{
config,
pkgs,
lib,
...
}:
let
cfg = config.shb.zfs;
in
{
options.shb.zfs = {
defaultPoolName = lib.mkOption {
type = lib.types.nullOr lib.types.str;
default = null;
description = "ZFS pool name datasets should be created on if no pool name is given in the dataset.";
};
datasets = lib.mkOption {
description = ''
ZFS Datasets.
Each entry in the attrset will be created and mounted in the given path.
The attrset name is the dataset name.
This block implements the following contracts:
- mount
'';
default = { };
example = lib.literalExpression ''
shb.zfs."safe/postgresql".path = "/var/lib/postgresql";
'';
type = lib.types.attrsOf (
lib.types.submodule {
options = {
enable = lib.mkEnableOption "shb.zfs.datasets";
poolName = lib.mkOption {
type = lib.types.nullOr lib.types.str;
default = null;
description = "ZFS pool name this dataset should be created on. Overrides the defaultPoolName.";
};
path = lib.mkOption {
type = lib.types.str;
description = "Path this dataset should be mounted on. If the string 'none' is given, the dataset will not be mounted.";
};
mode = lib.mkOption {
type = lib.types.nullOr lib.types.str;
description = "If non null, unix mode to apply to the dataset root folder.";
default = null;
example = "ug=rwx,g+s";
};
owner = lib.mkOption {
type = lib.types.nullOr lib.types.str;
description = "If non null, unix user to apply to the dataset root folder.";
default = null;
example = "syncthing";
};
group = lib.mkOption {
type = lib.types.nullOr lib.types.str;
description = "If non null, unix group to apply to the dataset root folder.";
default = null;
example = "syncthing";
};
defaultACLs = lib.mkOption {
type = lib.types.nullOr lib.types.str;
description = ''
If non null, default ACL to set on the dataset root folder.
Executes "setfacl -d -m $acl $path"
'';
default = null;
example = "g:syncthing:rwX";
};
};
}
);
};
};
config = {
assertions = [
{
assertion =
lib.any (x: x.poolName == null) (lib.mapAttrsToList (n: v: v) cfg.datasets)
-> cfg.defaultPoolName != null;
message = "Cannot have both datasets.poolName and defaultPoolName set to null";
}
];
system.activationScripts = lib.mapAttrs' (
name: cfg':
let
dataset = (if cfg'.poolName != null then cfg'.poolName else cfg.defaultPoolName) + "/" + name;
in
lib.attrsets.nameValuePair "zfsCreate-${name}" {
text = ''
${pkgs.zfs}/bin/zfs list ${dataset} > /dev/null 2>&1 \
|| ${pkgs.zfs}/bin/zfs create \
-o mountpoint=none \
${dataset} || :
[ "$(${pkgs.zfs}/bin/zfs get -H mountpoint -o value ${dataset})" = ${cfg'.path} ] \
|| ${pkgs.zfs}/bin/zfs set \
mountpoint="${cfg'.path}" \
${dataset}
''
+ lib.optionalString (cfg'.path != "none" && cfg'.mode != null) ''
chmod "${cfg'.mode}" "${cfg'.path}"
''
+ lib.optionalString (cfg'.path != "none" && cfg'.owner != null) ''
chown "${cfg'.owner}" "${cfg'.path}"
''
+ lib.optionalString (cfg'.path != "none" && cfg'.group != null) ''
chown :"${cfg'.group}" "${cfg'.path}"
''
+ lib.optionalString (cfg'.path != "none" && cfg'.defaultACLs != null) ''
${pkgs.acl}/bin/setfacl -d -m "${cfg'.defaultACLs}" "${cfg'.path}"
'';
}
) cfg.datasets;
};
}