nixpkgs/nixos/modules/services/logging/logcheck.nix
2022-11-10 09:30:00 +01:00

236 lines
6.4 KiB
Nix

{ config, lib, pkgs, ... }:
with lib;
let
cfg = config.services.logcheck;
defaultRules = pkgs.runCommand "logcheck-default-rules" { preferLocalBuild = true; } ''
cp -prd ${pkgs.logcheck}/etc/logcheck $out
chmod u+w $out
rm -r $out/logcheck.*
'';
rulesDir = pkgs.symlinkJoin
{ name = "logcheck-rules-dir";
paths = ([ defaultRules ] ++ cfg.extraRulesDirs);
};
configFile = pkgs.writeText "logcheck.conf" cfg.config;
logFiles = pkgs.writeText "logcheck.logfiles" cfg.files;
flags = "-r ${rulesDir} -c ${configFile} -L ${logFiles} -${levelFlag} -m ${cfg.mailTo}";
levelFlag = getAttrFromPath [cfg.level]
{ paranoid = "p";
server = "s";
workstation = "w";
};
cronJob = ''
@reboot logcheck env PATH=/run/wrappers/bin:$PATH nice -n10 ${pkgs.logcheck}/sbin/logcheck -R ${flags}
2 ${cfg.timeOfDay} * * * logcheck env PATH=/run/wrappers/bin:$PATH nice -n10 ${pkgs.logcheck}/sbin/logcheck ${flags}
'';
writeIgnoreRule = name: {level, regex, ...}:
pkgs.writeTextFile
{ inherit name;
destination = "/ignore.d.${level}/${name}";
text = ''
^\w{3} [ :[:digit:]]{11} [._[:alnum:]-]+ ${regex}
'';
};
writeIgnoreCronRule = name: {level, user, regex, cmdline, ...}:
let escapeRegex = escape (stringToCharacters "\\[]{}()^$?*+|.");
cmdline_ = builtins.unsafeDiscardStringContext cmdline;
re = if regex != "" then regex else if cmdline_ == "" then ".*" else escapeRegex cmdline_;
in writeIgnoreRule "cron-${name}" {
inherit level;
regex = ''
(/usr/bin/)?cron\[[0-9]+\]: \(${user}\) CMD \(${re}\)$
'';
};
levelOption = mkOption {
default = "server";
type = types.enum [ "workstation" "server" "paranoid" ];
description = lib.mdDoc ''
Set the logcheck level.
'';
};
ignoreOptions = {
options = {
level = levelOption;
regex = mkOption {
default = "";
type = types.str;
description = lib.mdDoc ''
Regex specifying which log lines to ignore.
'';
};
};
};
ignoreCronOptions = {
options = {
user = mkOption {
default = "root";
type = types.str;
description = lib.mdDoc ''
User that runs the cronjob.
'';
};
cmdline = mkOption {
default = "";
type = types.str;
description = lib.mdDoc ''
Command line for the cron job. Will be turned into a regex for the logcheck ignore rule.
'';
};
timeArgs = mkOption {
default = null;
type = types.nullOr (types.str);
example = "02 06 * * *";
description = lib.mdDoc ''
"min hr dom mon dow" crontab time args, to auto-create a cronjob too.
Leave at null to not do this and just add a logcheck ignore rule.
'';
};
};
};
in
{
options = {
services.logcheck = {
enable = mkEnableOption (lib.mdDoc "logcheck cron job");
user = mkOption {
default = "logcheck";
type = types.str;
description = lib.mdDoc ''
Username for the logcheck user.
'';
};
timeOfDay = mkOption {
default = "*";
example = "6";
type = types.str;
description = lib.mdDoc ''
Time of day to run logcheck. A logcheck will be scheduled at xx:02 each day.
Leave default (*) to run every hour. Of course when nothing special was logged,
logcheck will be silent.
'';
};
mailTo = mkOption {
default = "root";
example = "you@domain.com";
type = types.str;
description = lib.mdDoc ''
Email address to send reports to.
'';
};
level = mkOption {
default = "server";
type = types.str;
description = lib.mdDoc ''
Set the logcheck level. Either "workstation", "server", or "paranoid".
'';
};
config = mkOption {
default = "FQDN=1";
type = types.lines;
description = lib.mdDoc ''
Config options that you would like in logcheck.conf.
'';
};
files = mkOption {
default = [ "/var/log/messages" ];
type = types.listOf types.path;
example = [ "/var/log/messages" "/var/log/mail" ];
description = lib.mdDoc ''
Which log files to check.
'';
};
extraRulesDirs = mkOption {
default = [];
example = [ "/etc/logcheck" ];
type = types.listOf types.path;
description = lib.mdDoc ''
Directories with extra rules.
'';
};
ignore = mkOption {
default = {};
description = lib.mdDoc ''
This option defines extra ignore rules.
'';
type = with types; attrsOf (submodule ignoreOptions);
};
ignoreCron = mkOption {
default = {};
description = lib.mdDoc ''
This option defines extra ignore rules for cronjobs.
'';
type = with types; attrsOf (submodule ignoreCronOptions);
};
extraGroups = mkOption {
default = [];
type = types.listOf types.str;
example = [ "postdrop" "mongodb" ];
description = lib.mdDoc ''
Extra groups for the logcheck user, for example to be able to use sendmail,
or to access certain log files.
'';
};
};
};
config = mkIf cfg.enable {
services.logcheck.extraRulesDirs =
mapAttrsToList writeIgnoreRule cfg.ignore
++ mapAttrsToList writeIgnoreCronRule cfg.ignoreCron;
users.users = optionalAttrs (cfg.user == "logcheck") {
logcheck = {
group = "logcheck";
isSystemUser = true;
shell = "/bin/sh";
description = "Logcheck user account";
extraGroups = cfg.extraGroups;
};
};
users.groups = optionalAttrs (cfg.user == "logcheck") {
logcheck = {};
};
system.activationScripts.logcheck = ''
mkdir -m 700 -p /var/{lib,lock}/logcheck
chown ${cfg.user} /var/{lib,lock}/logcheck
'';
services.cron.systemCronJobs =
let withTime = name: {timeArgs, ...}: timeArgs != null;
mkCron = name: {user, cmdline, timeArgs, ...}: ''
${timeArgs} ${user} ${cmdline}
'';
in mapAttrsToList mkCron (filterAttrs withTime cfg.ignoreCron)
++ [ cronJob ];
};
}