nixpkgs/nixos/modules/services/web-servers/uwsgi.nix
2021-01-25 14:05:39 +01:00

232 lines
7.3 KiB
Nix

{ config, lib, pkgs, ... }:
with lib;
let
cfg = config.services.uwsgi;
isEmperor = cfg.instance.type == "emperor";
imperialPowers =
[
# spawn other user processes
"CAP_SETUID" "CAP_SETGID"
"CAP_SYS_CHROOT"
# transfer capabilities
"CAP_SETPCAP"
# create other user sockets
"CAP_CHOWN"
];
buildCfg = name: c:
let
plugins =
if any (n: !any (m: m == n) cfg.plugins) (c.plugins or [])
then throw "`plugins` attribute in uWSGI configuration contains plugins not in config.services.uwsgi.plugins"
else c.plugins or cfg.plugins;
hasPython = v: filter (n: n == "python${v}") plugins != [];
hasPython2 = hasPython "2";
hasPython3 = hasPython "3";
python =
if hasPython2 && hasPython3 then
throw "`plugins` attribute in uWSGI configuration shouldn't contain both python2 and python3"
else if hasPython2 then cfg.package.python2
else if hasPython3 then cfg.package.python3
else null;
pythonEnv = python.withPackages (c.pythonPackages or (self: []));
uwsgiCfg = {
uwsgi =
if c.type == "normal"
then {
inherit plugins;
} // removeAttrs c [ "type" "pythonPackages" ]
// optionalAttrs (python != null) {
pyhome = "${pythonEnv}";
env =
# Argh, uwsgi expects list of key-values there instead of a dictionary.
let env' = c.env or [];
getPath =
x: if hasPrefix "PATH=" x
then substring (stringLength "PATH=") (stringLength x) x
else null;
oldPaths = filter (x: x != null) (map getPath env');
in env' ++ [ "PATH=${optionalString (oldPaths != []) "${last oldPaths}:"}${pythonEnv}/bin" ];
}
else if isEmperor
then {
emperor = if builtins.typeOf c.vassals != "set" then c.vassals
else pkgs.buildEnv {
name = "vassals";
paths = mapAttrsToList buildCfg c.vassals;
};
} // removeAttrs c [ "type" "vassals" ]
else throw "`type` attribute in uWSGI configuration should be either 'normal' or 'emperor'";
};
in pkgs.writeTextDir "${name}.json" (builtins.toJSON uwsgiCfg);
in {
options = {
services.uwsgi = {
enable = mkOption {
type = types.bool;
default = false;
description = "Enable uWSGI";
};
runDir = mkOption {
type = types.path;
default = "/run/uwsgi";
description = "Where uWSGI communication sockets can live";
};
package = mkOption {
type = types.package;
internal = true;
};
instance = mkOption {
type = with types; let
valueType = nullOr (oneOf [
bool
int
float
str
(lazyAttrsOf valueType)
(listOf valueType)
(mkOptionType {
name = "function";
description = "function";
check = x: isFunction x;
merge = mergeOneOption;
})
]) // {
description = "Json value or lambda";
emptyValue.value = {};
};
in valueType;
default = {
type = "normal";
};
example = literalExample ''
{
type = "emperor";
vassals = {
moin = {
type = "normal";
pythonPackages = self: with self; [ moinmoin ];
socket = "${config.services.uwsgi.runDir}/uwsgi.sock";
};
};
}
'';
description = ''
uWSGI configuration. It awaits an attribute <literal>type</literal> inside which can be either
<literal>normal</literal> or <literal>emperor</literal>.
For <literal>normal</literal> mode you can specify <literal>pythonPackages</literal> as a function
from libraries set into a list of libraries. <literal>pythonpath</literal> will be set accordingly.
For <literal>emperor</literal> mode, you should use <literal>vassals</literal> attribute
which should be either a set of names and configurations or a path to a directory.
Other attributes will be used in configuration file as-is. Notice that you can redefine
<literal>plugins</literal> setting here.
'';
};
plugins = mkOption {
type = types.listOf types.str;
default = [];
description = "Plugins used with uWSGI";
};
user = mkOption {
type = types.str;
default = "uwsgi";
description = "User account under which uWSGI runs.";
};
group = mkOption {
type = types.str;
default = "uwsgi";
description = "Group account under which uWSGI runs.";
};
capabilities = mkOption {
type = types.listOf types.str;
apply = caps: caps ++ optionals isEmperor imperialPowers;
default = [ ];
example = literalExample ''
[
"CAP_NET_BIND_SERVICE" # bind on ports <1024
"CAP_NET_RAW" # open raw sockets
]
'';
description = ''
Grant capabilities to the uWSGI instance. See the
<literal>capabilities(7)</literal> for available values.
<note>
<para>
uWSGI runs as an unprivileged user (even as Emperor) with the minimal
capabilities required. This option can be used to add fine-grained
permissions without running the service as root.
</para>
<para>
When in Emperor mode, any capability to be inherited by a vassal must
be specified again in the vassal configuration using <literal>cap</literal>.
See the uWSGI <link
xlink:href="https://uwsgi-docs.readthedocs.io/en/latest/Capabilities.html">docs</link>
for more information.
</para>
</note>
'';
};
};
};
config = mkIf cfg.enable {
systemd.tmpfiles.rules = optional (cfg.runDir != "/run/uwsgi") ''
d ${cfg.runDir} 775 ${cfg.user} ${cfg.group}
'';
systemd.services.uwsgi = {
wantedBy = [ "multi-user.target" ];
serviceConfig = {
User = cfg.user;
Group = cfg.group;
Type = "notify";
ExecStart = "${cfg.package}/bin/uwsgi --json ${buildCfg "server" cfg.instance}/server.json";
ExecReload = "${pkgs.coreutils}/bin/kill -HUP $MAINPID";
ExecStop = "${pkgs.coreutils}/bin/kill -INT $MAINPID";
NotifyAccess = "main";
KillSignal = "SIGQUIT";
AmbientCapabilities = cfg.capabilities;
CapabilityBoundingSet = cfg.capabilities;
RuntimeDirectory = mkIf (cfg.runDir == "/run/uwsgi") "uwsgi";
};
};
users.users = optionalAttrs (cfg.user == "uwsgi") {
uwsgi = {
group = cfg.group;
uid = config.ids.uids.uwsgi;
};
};
users.groups = optionalAttrs (cfg.group == "uwsgi") {
uwsgi.gid = config.ids.gids.uwsgi;
};
services.uwsgi.package = pkgs.uwsgi.override {
inherit (cfg) plugins;
};
};
}