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

134 lines
4.7 KiB
Nix

{
config,
lib,
...
}: {
# options.storage = {
# zfs = {
# # TODO: enable option
# # when this option is enabled we need to configure and enable disko things
# # TODO: we need some way of managing notifications
# # TODO: we need options to configure zfs pools
# # we should have warnings when the configured pool is missing drives
# # 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
# # TODO: pools and datasets need to be passed to disko
# };
# impermanence = {
# # TODO: enable option
# # 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
# # Then we should make a dataset for user folders local and persist
# # We should also create datasets for systemd modules that have have impermanence enabled for them
# # we need to figure out what options a dataset can have in zfs
# };
# # 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";
}
)
];
}