nixpkgs/nixos/modules/services/torrent/transmission.nix

157 lines
5.8 KiB
Nix

{ config, lib, pkgs, ... }:
with lib;
let
cfg = config.services.transmission;
apparmor = config.security.apparmor.enable;
homeDir = "/var/lib/transmission";
downloadDir = "${homeDir}/Downloads";
incompleteDir = "${homeDir}/.incomplete";
settingsDir = "${homeDir}/.config/transmission-daemon";
settingsFile = "${settingsDir}/settings.json";
# Strings must be quoted, ints and bools must not (for settings.json).
toOption = x:
if x == true then "true"
else if x == false then "false"
else if isInt x then toString x
else toString ''\"${x}\"'';
# All lines in settings.json end with a ',' (comma), except for the last
# line. This is standard JSON. But a comma can also appear *inside* some
# fields, notably the "rpc-whitelist" field. This is difficult to handle in
# sed so we simply ignore it and say that if you want to change the option at
# the last line of settings.json, you have to do it manually. At this time of
# writing, the last option is "utp-enable":true.
attrsToSedArgs = as:
concatStrings (concatLists (mapAttrsToList (name: value:
#map (x: '' -e 's=\(\"${name}\":\)[^,]*\(.*\)=\1 ${toOption x}\2=' '') # breaks if comma inside value field
map (x: '' -e 's=\(\"${name}\":\).*=\1 ${toOption x},=' '') # always append ',' (breaks last line in settings.json)
(if isList value then value else [value]))
as));
# for users in group "transmission" to have access to torrents
fullSettings = cfg.settings // { umask = 2; };
in
{
options = {
services.transmission = {
enable = mkOption {
type = types.uniq types.bool;
default = false;
description = ''
Whether or not to enable the headless Transmission BitTorrent daemon.
Transmission daemon can be controlled via the RPC interface using
transmission-remote or the WebUI (http://localhost:9091/ by default).
Torrents are downloaded to ${homeDir}/Downloads/ by default and are
accessible to users in the "transmission" group.
'';
};
settings = mkOption {
type = types.attrs;
default =
{
download-dir = downloadDir;
incomplete-dir = incompleteDir;
incomplete-dir-enabled = true;
};
example =
{
download-dir = "/srv/torrents/";
incomplete-dir = "/srv/torrents/.incomplete/";
incomplete-dir-enabled = true;
rpc-whitelist = "127.0.0.1,192.168.*.*";
};
description = ''
Attribute set whos fields overwrites fields in settings.json (each
time the service starts). String values must be quoted, integer and
boolean values must not.
See https://trac.transmissionbt.com/wiki/EditConfigFiles for
documentation and/or look at ${settingsFile}.
'';
};
port = mkOption {
type = types.uniq types.int;
default = 9091;
description = "TCP port number to run the RPC/web interface.";
};
};
};
config = mkIf cfg.enable {
systemd.services.transmission = {
description = "Transmission BitTorrent Service";
after = [ "network.target" ] ++ optional apparmor "apparmor.service";
requires = mkIf apparmor [ "apparmor.service" ];
wantedBy = [ "multi-user.target" ];
# 1) Only the "transmission" user and group have access to torrents.
# 2) Optionally update/force specific fields into the configuration file.
serviceConfig.ExecStartPre = ''
${pkgs.stdenv.shell} -c "chmod 770 ${homeDir} && mkdir -p ${settingsDir} ${downloadDir} ${incompleteDir} && ${pkgs.transmission}/bin/transmission-daemon -d |& sed ${attrsToSedArgs fullSettings} > ${settingsFile}.tmp && mv ${settingsFile}.tmp ${settingsFile}"
'';
serviceConfig.ExecStart = "${pkgs.transmission}/bin/transmission-daemon -f --port ${toString config.services.transmission.port}";
serviceConfig.ExecReload = "${pkgs.coreutils}/bin/kill -HUP $MAINPID";
serviceConfig.User = "transmission";
# NOTE: transmission has an internal umask that also must be set (in settings.json)
serviceConfig.UMask = "0002";
};
# It's useful to have transmission in path, e.g. for remote control
environment.systemPackages = [ pkgs.transmission ];
users.extraGroups.transmission.gid = config.ids.gids.transmission;
users.extraUsers.transmission = {
group = "transmission";
uid = config.ids.uids.transmission;
description = "Transmission BitTorrent user";
home = homeDir;
createHome = true;
};
# AppArmor profile
security.apparmor.profiles = mkIf apparmor [
(pkgs.writeText "apparmor-transmission-daemon" ''
#include <tunables/global>
${pkgs.transmission}/bin/transmission-daemon {
#include <abstractions/base>
#include <abstractions/nameservice>
${pkgs.glibc}/lib/*.so mr,
${pkgs.libevent}/lib/libevent*.so* mr,
${pkgs.curl}/lib/libcurl*.so* mr,
${pkgs.openssl}/lib/libssl*.so* mr,
${pkgs.openssl}/lib/libcrypto*.so* mr,
${pkgs.zlib}/lib/libz*.so* mr,
${pkgs.libssh2}/lib/libssh2*.so* mr,
${pkgs.systemd}/lib/libsystemd*.so* mr,
${pkgs.xz}/lib/liblzma*.so* mr,
${pkgs.libgcrypt}/lib/libgcrypt*.so* mr,
${pkgs.libgpgerror}/lib/libgpg-error*.so* mr,
@{PROC}/sys/kernel/random/uuid r,
@{PROC}/sys/vm/overcommit_memory r,
${pkgs.transmission}/share/transmission/** r,
owner ${settingsDir}/** rw,
${fullSettings.download-dir}/** rw,
${optionalString fullSettings.incomplete-dir-enabled ''
${fullSettings.incomplete-dir}/** rw,
''}
}
'')
];
};
}