Files
nix-files/hosts/modules/services/rsync-net/default.nix

101 lines
3.7 KiB
Nix

{ config, lib, pkgs, ... }:
let
cfg = config.sane.services.rsync-net;
sane-backup-rsync-net = pkgs.static-nix-shell.mkBash {
pname = "sane-backup-rsync-net";
pkgs = [
"nettools"
"openssh"
"rsync"
"sane-scripts.vpn"
];
srcRoot = ./.;
};
in
{
options = with lib; {
sane.services.rsync-net.enable = mkEnableOption "periodically backup data to rsync.net";
sane.services.rsync-net.dirs = mkOption {
type = types.listOf types.str;
description = ''
list of directories to upload to rsync.net.
note that this module does NOT add any encryption to the files (layer that yourself).
'';
default = lib.optionals config.sane.persist.enable [
"/nix/persist/private" #< XXX: make sure to do the encrypted version, not /mnt/persist/private!
];
};
};
config = lib.mkIf cfg.enable {
systemd.services.rsync-net = {
description = "backup files to rsync.net";
serviceConfig.ExecStart = "${lib.getExe sane-backup-rsync-net} ${lib.escapeShellArgs cfg.dirs}";
serviceConfig.Type = "simple";
serviceConfig.Restart = "no";
serviceConfig.User = "colin";
serviceConfig.AmbientCapabilities = [
# needs to be able to read files owned by any user
"CAP_DAC_READ_SEARCH"
];
serviceConfig.RestrictNetworkInterfaces = [
# strictly forbid sending traffic over any non ethernet/wifi interface,
# because i don't want this e.g. consuming all my cellular data.
# TODO: test this. i don't know that the moby kernel/systemd actually supports these options
"lo" # for DNS
"eth0"
"wlan0"
];
# hardening
serviceConfig.CapabilityBoundingSet = [ "CAP_DAC_READ_SEARCH" ];
serviceConfig.ReadWritePaths = builtins.map (d: "${d}/zzz-rsync-net") cfg.dirs;
serviceConfig.ReadOnlyPaths = cfg.dirs;
serviceConfig.RestrictAddressFamilies = "AF_INET AF_INET6";
serviceConfig.LockPersonality = true;
serviceConfig.MemoryDenyWriteExecute = true;
serviceConfig.NoNewPrivileges = true;
serviceConfig.PrivateDevices = true;
serviceConfig.PrivateMounts = true;
serviceConfig.PrivateTmp = true;
serviceConfig.ProcSubset = "pid";
serviceConfig.ProtectClock = true;
serviceConfig.ProtectControlGroups = true;
serviceConfig.ProtectHome = true;
serviceConfig.ProtectHostname = true;
serviceConfig.ProtectKernelLogs = true;
serviceConfig.ProtectKernelModules = true;
serviceConfig.ProtectKernelTunables = true;
serviceConfig.ProtectProc = "invisible";
serviceConfig.ProtectSystem = "strict";
serviceConfig.RemoveIPC = true;
serviceConfig.RestrictFileSystems = "@basic-api @common-block @temporary";
serviceConfig.RestrictNamespaces = true;
serviceConfig.RestrictSUIDSGID = true;
serviceConfig.SystemCallArchitectures = "native";
serviceConfig.SystemCallFilter = [
"@system-service"
"~@chown"
"~@cpu-emulation"
"~@keyring"
"~@setuid"
];
# hardening exceptions:
serviceConfig.PrivateUsers = false; #< CAP_DAC_READ_SEARCH in the root namespace means we can't do any user namespacing
# serviceConfig.NoNewPrivileges = false; #< bwrap'd dac_read_search
# serviceConfig.PrivateDevices = false; #< passt/pasta
# serviceConfig.RestrictNamespaces = false; #< bwrap
# serviceConfig.RestrictAddressFamilies = "AF_UNIX AF_INET AF_INET6 AF_NETLINK"; #< AF_NETLINK is for passt/pasta
};
systemd.timers.rsync-net = {
wantedBy = [ "multi-user.target" ];
timerConfig = {
# run 2x daily; at 11:00:00, 23:00:00
OnCalendar = "11,23:00:00";
};
};
};
}