nix-config/modules/nixos-modules/impermanence.nix

241 lines
8.3 KiB
Nix

{
config,
lib,
...
}: {
options.storage = let
datasetSubmodule = {name, ...}: {
# TODO: we need to figure out what options a dataset can have in zfs
};
impermanenceDatasetSubmodules = [
datasetSubmodule
({...}: let
pathPermissions = {
read = lib.mkEnableOption "should the path have read permissions";
write = lib.mkEnableOption "should the path have read permissions";
execute = lib.mkEnableOption "should the path have read permissions";
};
pathTypeSubmodule = {name, ...}: {
options = {
enable = lib.mkOption {
type = lib.types.bool;
default = true;
};
owner = {
user = lib.mkOption {
type = lib.types.str;
default = "nouser";
};
permissions = pathPermissions;
};
group = {
group = lib.mkOption {
type = lib.types.str;
default = "nogroup";
};
permissions = pathPermissions;
};
other = {
permissions = pathPermissions;
};
};
};
in {
options = {
files = lib.types.mkOption {
type = lib.types.attrsOf (lib.types.submodule pathTypeSubmodule);
default = {};
};
directories = {
type = lib.types.attrsOf (lib.types.submodule pathTypeSubmodule);
default = {};
};
};
})
];
in {
zfs = {
# TODO: enable option implementation
enable = lib.mkEnableOption "Should zfs be enabled on this system.";
notifications = {
enable = lib.mkEnableOption "are notifications enabled";
host = lib.mkOption {
type = lib.types.str;
description = "what is the host that we are going to send the email to";
};
port = lib.mkOption {
type = lib.types.port;
description = "what port is the host using to receive mail on";
};
to = lib.mkOption {
type = lib.types.str;
description = "what account is the email going to be sent to";
};
user = lib.mkOption {
type = lib.types.str;
description = "what user is the email going to be set from";
};
tokenFile = lib.mkOption {
type = lib.types.str;
description = "file containing the password to be used by msmtp for notifications";
};
};
# TODO: we need options to configure zfs pools
# we should have warnings when the configured pool is missing drives after activation
# TODO: implementation of this
# TODO: validations that we have at least one boot drive
pool = let
deviceType =
lib.types.coercedTo lib.types.str (device: {
device = device;
boot = false;
}) {
device = lib.mkOption {
type = lib.types.str;
};
boot = lib.mkEnableOption "should this device be a boot device";
};
in {
encryption = lib.mkEnableOption "Should encryption be enabled on this pool.";
vdevs = lib.mkOption {
type = lib.types.listOf deviceType;
default = [];
};
cache = lib.mkOption {
type = lib.types.attrsOf deviceType;
};
};
# TODO:create the root dataset automatically
# TODO: dataset option that is a submodule that adds datasets to the system
# warnings for when a dataset was created in the past on a system but it is now missing some of the options defined for it
datasets = lib.types.attrsOf (lib.types.submodule datasetSubmodule);
};
impermanence = {
enable = lib.mkEnableOption "should impermanence be enabled for this system";
# TODO: enable option implementation
# TODO: assertion that zfs needs to be enabled when impermanence is enabled
# TODO: datasets option that is a submodule that will be used to define what datasets to add to the storage system
# We should by default create the `local`, `local/system/nix`, `local/system/root`, `persist` `persist/system/root`, and `persist/system/var/log` datasets
# We should also create datasets for systemd modules that have have impermanence enabled for them
datasets = lib.types.attrsOf (lib.types.submodule impermanenceDatasetSubmodules);
# TODO: this should just live under home-manager.users.<user>.storage.impermanence
home-manager = lib.types.attrsOf (lib.types.submodule ({name, ...}: {
enable = lib.mkEnableOption "should impermanence be enabled for this user";
# We should by default create the `local/home/${name}`, and `persist/home/${name}` datasets
datasets = lib.types.attrsOf (lib.types.submodule impermanenceDatasetSubmodules);
}));
};
# TODO: we should have an impermanence module for home manager that proxies its values namespaced to the user down here that matches the same interface
# TODO: we should have a way of enabling impermanence for a systemd config
# these should have an option to put their folder into their own dataset (this needs to support private vs non private)
# options for features that can be added to the dataset
};
options.host.impermanence.enable = lib.mkEnableOption "are we going to use impermanence on this device";
config = lib.mkMerge [
{
assertions = [
{
assertion = !(config.host.impermanence.enable && !config.host.storage.enable);
message = ''
Disko storage must be enabled to use impermanence.
'';
}
];
}
(
lib.mkIf config.host.impermanence.enable {
assertions = [
{
assertion = config.host.impermanence.enable && config.host.storage.enable;
message = "Impermanence can not be used without managed host storage.";
}
];
# fixes issues with /var/lib/private not having the correct permissions https://github.com/nix-community/impermanence/issues/254
system.activationScripts."createPersistentStorageDirs".deps = ["var-lib-private-permissions" "users" "groups"];
system.activationScripts = {
"var-lib-private-permissions" = {
deps = ["specialfs"];
text = ''
mkdir -p /persist/system/root/var/lib/private
chmod 0700 /persist/system/root/var/lib/private
'';
};
};
programs.fuse.userAllowOther = true;
boot.initrd.postResumeCommands = lib.mkAfter ''
zfs rollback -r rpool/local/system/root@blank
'';
fileSystems = {
"/".neededForBoot = true;
"/persist/system/root".neededForBoot = true;
"/persist/system/var/log".neededForBoot = true;
};
host.storage.pool.extraDatasets = {
# persist datasets are datasets that contain information that we would like to keep around
"persist" = {
type = "zfs_fs";
options.canmount = "off";
options = {
"com.sun:auto-snapshot" = "true";
};
};
# this is where root data actually lives
"persist/system/root" = {
type = "zfs_fs";
mountpoint = "/persist/system/root";
};
"persist/system/var/log" = {
type = "zfs_fs";
mountpoint = "/persist/system/var/log";
# logs should be append only so we shouldn't need to snapshot them
options = {
"com.sun:auto-snapshot" = "false";
};
};
};
environment.persistence."/persist/system/var/log" = {
enable = true;
hideMounts = true;
directories = [
"/var/log"
];
};
environment.persistence."/persist/system/root" = {
enable = true;
hideMounts = true;
directories = [
"/var/lib/nixos"
"/var/lib/systemd/coredump"
];
files = [
"/etc/machine-id"
];
};
# TODO: this should live in leylas home manager configuration
security.sudo.extraConfig = "Defaults lecture=never";
}
)
];
}