nixpkgs-suyu/nixos/modules/services/networking/haproxy.nix
Hugo Geoffroy c784d3ab76 nixos/haproxy: add reloading support, use upstream service hardening
Refactor the systemd service definition for the haproxy reverse proxy,
using the upstream systemd service definition. This allows the service
to be reloaded on changes, preserving existing server state, and adds
some hardening options.
2020-05-31 22:35:27 +02:00

112 lines
3.2 KiB
Nix

{ config, lib, pkgs, ... }:
let
cfg = config.services.haproxy;
haproxyCfg = pkgs.writeText "haproxy.conf" ''
global
# needed for hot-reload to work without dropping packets in multi-worker mode
stats socket /run/haproxy/haproxy.sock mode 600 expose-fd listeners level user
${cfg.config}
'';
in
with lib;
{
options = {
services.haproxy = {
enable = mkOption {
type = types.bool;
default = false;
description = ''
Whether to enable HAProxy, the reliable, high performance TCP/HTTP
load balancer.
'';
};
user = mkOption {
type = types.str;
default = "haproxy";
description = "User account under which haproxy runs.";
};
group = mkOption {
type = types.str;
default = "haproxy";
description = "Group account under which haproxy runs.";
};
config = mkOption {
type = types.nullOr types.lines;
default = null;
description = ''
Contents of the HAProxy configuration file,
<filename>haproxy.conf</filename>.
'';
};
};
};
config = mkIf cfg.enable {
assertions = [{
assertion = cfg.config != null;
message = "You must provide services.haproxy.config.";
}];
# configuration file indirection is needed to support reloading
environment.etc."haproxy.cfg".source = haproxyCfg;
systemd.services.haproxy = {
description = "HAProxy";
after = [ "network.target" ];
wantedBy = [ "multi-user.target" ];
serviceConfig = {
User = cfg.user;
Group = cfg.group;
Type = "notify";
ExecStartPre = [
# when the master process receives USR2, it reloads itself using exec(argv[0]),
# so we create a symlink there and update it before reloading
"${pkgs.coreutils}/bin/ln -sf ${pkgs.haproxy}/sbin/haproxy /run/haproxy/haproxy"
# when running the config test, don't be quiet so we can see what goes wrong
"/run/haproxy/haproxy -c -f ${haproxyCfg}"
];
ExecStart = "/run/haproxy/haproxy -Ws -f /etc/haproxy.cfg -p /run/haproxy/haproxy.pid";
# support reloading
ExecReload = [
"${pkgs.haproxy}/sbin/haproxy -c -f ${haproxyCfg}"
"${pkgs.coreutils}/bin/ln -sf ${pkgs.haproxy}/sbin/haproxy /run/haproxy/haproxy"
"${pkgs.coreutils}/bin/kill -USR2 $MAINPID"
];
KillMode = "mixed";
SuccessExitStatus = "143";
Restart = "always";
RuntimeDirectory = "haproxy";
# upstream hardening options
NoNewPrivileges = true;
ProtectHome = true;
ProtectSystem = "strict";
ProtectKernelTunables = true;
ProtectKernelModules = true;
ProtectControlGroups = true;
SystemCallFilter= "~@cpu-emulation @keyring @module @obsolete @raw-io @reboot @swap @sync";
# needed in case we bind to port < 1024
AmbientCapabilities = "CAP_NET_BIND_SERVICE";
};
};
users.users = optionalAttrs (cfg.user == "haproxy") {
haproxy = {
group = cfg.group;
isSystemUser = true;
};
};
users.groups = optionalAttrs (cfg.group == "haproxy") {
haproxy = {};
};
};
}