nixos-servers/nixos-modules/backups.nix

129 lines
4 KiB
Nix

{ pkgs, lib, config, ... }:
let
cfg = config.lab.backups;
beforeEverything = pkgs.writeShellScriptBin "beforeEverything" ''
if [ -d "${cfg.snapshotLocation}" ]; then
${pkgs.btrfs-progs}/bin/btrfs subvolume delete ${cfg.snapshotLocation}
fi
${pkgs.btrfs-progs}/bin/btrfs subvolume snapshot -r ${cfg.subvolumeLocation} ${cfg.snapshotLocation}
'';
borgmaticConfig = pkgs.writeTextFile {
name = "borgmatic-config.yaml";
text = lib.generators.toYAML { } {
source_directories = [ cfg.snapshotLocation ];
repositories = [
{
path = cfg.repoLocation;
label = "nfs";
}
{
path = "ssh://s6969ym3@s6969ym3.repo.borgbase.com/./repo";
label = "borgbase";
}
];
exclude_patterns = [ "${cfg.snapshotLocation}/media" ];
ssh_command = "${pkgs.openssh}/bin/ssh -i ${config.age.secrets."borgbase.pem".path} -o StrictHostKeychecking=no";
keep_daily = 7;
keep_weekly = 4;
keep_monthly = 12;
keep_yearly = -1;
encryption_passcommand = "${pkgs.coreutils}/bin/cat ${config.age.secrets."borg_passphrase".path}";
before_everything = [ "${beforeEverything}/bin/beforeEverything" ];
postgresql_databases = [
{
name = "nextcloud";
hostname = "lewis.dmz";
username = "nextcloud";
password = "\${NEXTCLOUD_DATABASE_PASSWORD}";
format = "tar";
}
];
};
};
in
{
options.lab.backups = {
enable = lib.mkOption {
default = false;
type = lib.types.bool;
description = ''
Whether to enable backups of persistent data on this machine.
'';
};
repoLocation = lib.mkOption {
default = "${config.lab.storage.dataMountPoint}/backups/nfs.borg";
type = lib.types.str;
description = ''
Location of the Borg repository to back up to.
'';
};
subvolumeLocation = lib.mkOption {
default = "${config.lab.storage.dataMountPoint}/nfs";
type = lib.types.str;
description = ''
Location of the btrfs subvolume holding the data.
'';
};
snapshotLocation = lib.mkOption {
default = "${config.lab.storage.dataMountPoint}/snapshot-nfs";
type = lib.types.str;
description = ''
Location to (temporary) create a snapshot of the subvolume.
'';
};
};
config = lib.mkIf cfg.enable {
environment.systemPackages = with pkgs; [ borgbackup postgresql ];
# Converted from:
# https://github.com/borgmatic-collective/borgmatic/tree/84823dfb912db650936e3492f6ead7e0e0d32a0f/sample/systemd
systemd.services.borgmatic = {
description = "borgmatic backup";
wants = [ "network-online.target" ];
after = [ "network-online.target" ];
unitConfig.ConditionACPower = true;
preStart = "${pkgs.coreutils}/bin/sleep 10s";
path = with pkgs; [ postgresql ];
serviceConfig = {
Type = "oneshot";
Nice = 19;
CPUSchedulingPolicy = "batch";
IOSchedulingClass = "best-effort";
IOSchedulingPriority = 7;
IOWeight = 100;
Restart = "no";
LogRateLimitIntervalSec = 0;
EnvironmentFile = config.age.secrets."database_passwords.env".path;
Environment = "BORG_PASSPHRASE_FILE=${config.age.secrets."borg_passphrase".path}";
};
script = "${pkgs.systemd}/bin/systemd-inhibit --who=\"borgmatic\" --what=\"sleep:shutdown\" --why=\"Prevent interrupting scheduled backup\" ${pkgs.borgmatic}/bin/borgmatic --verbosity -2 --syslog-verbosity 1 -c ${borgmaticConfig}";
};
systemd.timers.borgmatic = {
description = "Run borgmatic backup";
wantedBy = [ "timers.target" ];
timerConfig = {
OnCalendar = "*-*-* 3:00:00";
Persistent = true;
RandomizedDelaySec = "1h";
};
};
age.secrets = {
"database_passwords.env".file = ../secrets/database_passwords.env.age;
"borg_passphrase".file = ../secrets/borg_passphrase.age;
"borgbase.pem".file = ../secrets/borgbase.pem.age;
};
};
}