nixpkgs/nixos/modules/services/networking/syncthing.nix
Félix Baylac-Jacqué ff8f2928ee
nixos/syncthing.nix: Sandbox the systemd service.
Using systemd sandboxing features to harden the syncthing service.
2020-01-20 21:48:48 +01:00

527 lines
16 KiB
Nix

{ config, lib, pkgs, ... }:
with lib;
let
cfg = config.services.syncthing;
defaultUser = "syncthing";
devices = mapAttrsToList (name: device: {
deviceID = device.id;
inherit (device) name addresses introducer;
}) cfg.declarative.devices;
folders = mapAttrsToList ( _: folder: {
inherit (folder) path id label type;
devices = map (device: { deviceId = cfg.declarative.devices.${device}.id; }) folder.devices;
rescanIntervalS = folder.rescanInterval;
fsWatcherEnabled = folder.watch;
fsWatcherDelayS = folder.watchDelay;
ignorePerms = folder.ignorePerms;
versioning = folder.versioning;
}) (filterAttrs (
_: folder:
folder.enable
) cfg.declarative.folders);
# get the api key by parsing the config.xml
getApiKey = pkgs.writers.writeDash "getAPIKey" ''
${pkgs.libxml2}/bin/xmllint \
--xpath 'string(configuration/gui/apikey)'\
${cfg.configDir}/config.xml
'';
updateConfig = pkgs.writers.writeDash "merge-syncthing-config" ''
set -efu
# wait for syncthing port to open
until ${pkgs.curl}/bin/curl -Ss ${cfg.guiAddress} -o /dev/null; do
sleep 1
done
API_KEY=$(${getApiKey})
OLD_CFG=$(${pkgs.curl}/bin/curl -Ss \
-H "X-API-Key: $API_KEY" \
${cfg.guiAddress}/rest/system/config)
# generate the new config by merging with the nixos config options
NEW_CFG=$(echo "$OLD_CFG" | ${pkgs.jq}/bin/jq -s '.[] as $in | $in * {
"devices": (${builtins.toJSON devices}${optionalString (! cfg.declarative.overrideDevices) " + $in.devices"}),
"folders": (${builtins.toJSON folders}${optionalString (! cfg.declarative.overrideFolders) " + $in.folders"})
}')
# POST the new config to syncthing
echo "$NEW_CFG" | ${pkgs.curl}/bin/curl -Ss \
-H "X-API-Key: $API_KEY" \
${cfg.guiAddress}/rest/system/config -d @-
# restart syncthing after sending the new config
${pkgs.curl}/bin/curl -Ss \
-H "X-API-Key: $API_KEY" \
-X POST \
${cfg.guiAddress}/rest/system/restart
'';
in {
###### interface
options = {
services.syncthing = {
enable = mkEnableOption ''
Syncthing - the self-hosted open-source alternative
to Dropbox and Bittorrent Sync. Initial interface will be
available on http://127.0.0.1:8384/.
'';
declarative = {
cert = mkOption {
type = types.nullOr types.str;
default = null;
description = ''
Path to users cert.pem file, will be copied into the syncthing's
<literal>configDir</literal>
'';
};
key = mkOption {
type = types.nullOr types.str;
default = null;
description = ''
Path to users key.pem file, will be copied into the syncthing's
<literal>configDir</literal>
'';
};
overrideDevices = mkOption {
type = types.bool;
default = true;
description = ''
Whether to delete the devices which are not configured via the
<literal>declarative.devices</literal> option.
If set to false, devices added via the webinterface will
persist but will have to be deleted manually.
'';
};
devices = mkOption {
default = {};
description = ''
Peers/devices which syncthing should communicate with.
'';
example = {
bigbox = {
id = "7CFNTQM-IMTJBHJ-3UWRDIU-ZGQJFR6-VCXZ3NB-XUH3KZO-N52ITXR-LAIYUAU";
addresses = [ "tcp://192.168.0.10:51820" ];
};
};
type = types.attrsOf (types.submodule ({ name, ... }: {
options = {
name = mkOption {
type = types.str;
default = name;
description = ''
Name of the device
'';
};
addresses = mkOption {
type = types.listOf types.str;
default = [];
description = ''
The addresses used to connect to the device.
If this is let empty, dynamic configuration is attempted
'';
};
id = mkOption {
type = types.str;
description = ''
The id of the other peer, this is mandatory. It's documented at
https://docs.syncthing.net/dev/device-ids.html
'';
};
introducer = mkOption {
type = types.bool;
default = false;
description = ''
If the device should act as an introducer and be allowed
to add folders on this computer.
'';
};
};
}));
};
overrideFolders = mkOption {
type = types.bool;
default = true;
description = ''
Whether to delete the folders which are not configured via the
<literal>declarative.folders</literal> option.
If set to false, folders added via the webinterface will persist
but will have to be deleted manually.
'';
};
folders = mkOption {
default = {};
description = ''
folders which should be shared by syncthing.
'';
example = {
"/home/user/sync" = {
id = "syncme";
devices = [ "bigbox" ];
};
};
type = types.attrsOf (types.submodule ({ name, ... }: {
options = {
enable = mkOption {
type = types.bool;
default = true;
description = ''
share this folder.
This option is useful when you want to define all folders
in one place, but not every machine should share all folders.
'';
};
path = mkOption {
type = types.str;
default = name;
description = ''
The path to the folder which should be shared.
'';
};
id = mkOption {
type = types.str;
default = name;
description = ''
The id of the folder. Must be the same on all devices.
'';
};
label = mkOption {
type = types.str;
default = name;
description = ''
The label of the folder.
'';
};
devices = mkOption {
type = types.listOf types.str;
default = [];
description = ''
The devices this folder should be shared with. Must be defined
in the <literal>declarative.devices</literal> attribute.
'';
};
versioning = mkOption {
default = null;
description = ''
How to keep changed/deleted files with syncthing.
There are 4 different types of versioning with different parameters.
See https://docs.syncthing.net/users/versioning.html
'';
example = [
{
versioning = {
type = "simple";
params.keep = "10";
};
}
{
versioning = {
type = "trashcan";
params.cleanoutDays = "1000";
};
}
{
versioning = {
type = "staggered";
params = {
cleanInterval = "3600";
maxAge = "31536000";
versionsPath = "/syncthing/backup";
};
};
}
{
versioning = {
type = "external";
params.versionsPath = pkgs.writers.writeBash "backup" ''
folderpath="$1"
filepath="$2"
rm -rf "$folderpath/$filepath"
'';
};
}
];
type = with types; nullOr (submodule {
options = {
type = mkOption {
type = enum [ "external" "simple" "staggered" "trashcan" ];
description = ''
Type of versioning.
See https://docs.syncthing.net/users/versioning.html
'';
};
params = mkOption {
type = attrsOf (either str path);
description = ''
Parameters for versioning. Structure depends on versioning.type.
See https://docs.syncthing.net/users/versioning.html
'';
};
};
});
};
rescanInterval = mkOption {
type = types.int;
default = 3600;
description = ''
How often the folders should be rescaned for changes.
'';
};
type = mkOption {
type = types.enum [ "sendreceive" "sendonly" "receiveonly" ];
default = "sendreceive";
description = ''
Whether to send only changes from this folder, only receive them
or propagate both.
'';
};
watch = mkOption {
type = types.bool;
default = true;
description = ''
Whether the folder should be watched for changes by inotify.
'';
};
watchDelay = mkOption {
type = types.int;
default = 10;
description = ''
The delay after an inotify event is triggered.
'';
};
ignorePerms = mkOption {
type = types.bool;
default = true;
description = ''
Whether to propagate permission changes.
'';
};
};
}));
};
};
guiAddress = mkOption {
type = types.str;
default = "127.0.0.1:8384";
description = ''
Address to serve the GUI.
'';
};
systemService = mkOption {
type = types.bool;
default = true;
description = "Auto launch Syncthing as a system service.";
};
user = mkOption {
type = types.str;
default = defaultUser;
description = ''
Syncthing will be run under this user (user will be created if it doesn't exist.
This can be your user name).
'';
};
group = mkOption {
type = types.str;
default = defaultUser;
description = ''
Syncthing will be run under this group (group will not be created if it doesn't exist.
This can be your user name).
'';
};
all_proxy = mkOption {
type = with types; nullOr str;
default = null;
example = "socks5://address.com:1234";
description = ''
Overwrites all_proxy environment variable for the syncthing process to
the given value. This is normaly used to let relay client connect
through SOCKS5 proxy server.
'';
};
dataDir = mkOption {
type = types.path;
default = "/var/lib/syncthing";
description = ''
Path where synced directories will exist.
'';
};
configDir = mkOption {
type = types.path;
description = ''
Path where the settings and keys will exist.
'';
default =
let
nixos = config.system.stateVersion;
cond = versionAtLeast nixos "19.03";
in cfg.dataDir + (optionalString cond "/.config/syncthing");
};
openDefaultPorts = mkOption {
type = types.bool;
default = false;
example = literalExample "true";
description = ''
Open the default ports in the firewall:
- TCP 22000 for transfers
- UDP 21027 for discovery
If multiple users are running syncthing on this machine, you will need to manually open a set of ports for each instance and leave this disabled.
Alternatively, if are running only a single instance on this machine using the default ports, enable this.
'';
};
package = mkOption {
type = types.package;
default = pkgs.syncthing;
defaultText = "pkgs.syncthing";
example = literalExample "pkgs.syncthing";
description = ''
Syncthing package to use.
'';
};
};
};
imports = [
(mkRemovedOptionModule ["services" "syncthing" "useInotify"] ''
This option was removed because syncthing now has the inotify functionality included under the name "fswatcher".
It can be enabled on a per-folder basis through the webinterface.
'')
];
###### implementation
config = mkIf cfg.enable {
networking.firewall = mkIf cfg.openDefaultPorts {
allowedTCPPorts = [ 22000 ];
allowedUDPPorts = [ 21027 ];
};
systemd.packages = [ pkgs.syncthing ];
users.users = mkIf (cfg.systemService && cfg.user == defaultUser) {
${defaultUser} =
{ group = cfg.group;
home = cfg.dataDir;
createHome = true;
uid = config.ids.uids.syncthing;
description = "Syncthing daemon user";
};
};
users.groups = mkIf (cfg.systemService && cfg.group == defaultUser) {
${defaultUser}.gid =
config.ids.gids.syncthing;
};
systemd.services = {
syncthing = mkIf cfg.systemService {
description = "Syncthing service";
after = [ "network.target" ];
environment = {
STNORESTART = "yes";
STNOUPGRADE = "yes";
inherit (cfg) all_proxy;
} // config.networking.proxy.envVars;
wantedBy = [ "multi-user.target" ];
serviceConfig = {
Restart = "on-failure";
SuccessExitStatus = "2 3 4";
RestartForceExitStatus="3 4";
User = cfg.user;
Group = cfg.group;
ExecStartPre = mkIf (cfg.declarative.cert != null || cfg.declarative.key != null)
"+${pkgs.writers.writeBash "syncthing-copy-keys" ''
install -dm700 -o ${cfg.user} -g ${cfg.group} ${cfg.configDir}
${optionalString (cfg.declarative.cert != null) ''
install -Dm400 -o ${cfg.user} -g ${cfg.group} ${toString cfg.declarative.cert} ${cfg.configDir}/cert.pem
''}
${optionalString (cfg.declarative.key != null) ''
install -Dm400 -o ${cfg.user} -g ${cfg.group} ${toString cfg.declarative.key} ${cfg.configDir}/key.pem
''}
''}"
;
ExecStart = ''
${cfg.package}/bin/syncthing \
-no-browser \
-gui-address=${cfg.guiAddress} \
-home=${cfg.configDir}
'';
MemoryDenyWriteExecute = true;
NoNewPrivileges = true;
PrivateDevices = true;
PrivateMounts = true;
PrivateTmp = true;
PrivateUsers = true;
ProtectControlGroups = true;
ProtectHostname = true;
ProtectKernelModules = true;
ProtectKernelTunables = true;
RestrictNamespaces = true;
RestrictRealtime = true;
RestrictSUIDSGID = true;
CapabilityBoundingSet = [
"~CAP_SYS_PTRACE" "~CAP_SYS_ADMIN"
"~CAP_SETGID" "~CAP_SETUID" "~CAP_SETPCAP"
"~CAP_SYS_TIME" "~CAP_KILL"
];
};
};
syncthing-init = mkIf (
cfg.declarative.devices != {} || cfg.declarative.folders != {}
) {
after = [ "syncthing.service" ];
wantedBy = [ "multi-user.target" ];
serviceConfig = {
User = cfg.user;
RemainAfterExit = true;
Type = "oneshot";
ExecStart = updateConfig;
};
};
syncthing-resume = {
wantedBy = [ "suspend.target" ];
};
};
};
}