nixpkgs/nixos/modules/services/monitoring/nagios.nix
2021-08-08 12:00:00 +00:00

213 lines
6.7 KiB
Nix

# Nagios system/network monitoring daemon.
{ config, lib, pkgs, ... }:
with lib;
let
cfg = config.services.nagios;
nagiosState = "/var/lib/nagios";
nagiosLogDir = "/var/log/nagios";
urlPath = "/nagios";
nagiosObjectDefs = cfg.objectDefs;
nagiosObjectDefsDir = pkgs.runCommand "nagios-objects" {
inherit nagiosObjectDefs;
preferLocalBuild = true;
} "mkdir -p $out; ln -s $nagiosObjectDefs $out/";
nagiosCfgFile = let
default = {
log_file="${nagiosLogDir}/current";
log_archive_path="${nagiosLogDir}/archive";
status_file="${nagiosState}/status.dat";
object_cache_file="${nagiosState}/objects.cache";
temp_file="${nagiosState}/nagios.tmp";
lock_file="/run/nagios.lock";
state_retention_file="${nagiosState}/retention.dat";
query_socket="${nagiosState}/nagios.qh";
check_result_path="${nagiosState}";
command_file="${nagiosState}/nagios.cmd";
cfg_dir="${nagiosObjectDefsDir}";
nagios_user="nagios";
nagios_group="nagios";
illegal_macro_output_chars="`~$&|'\"<>";
retain_state_information="1";
};
lines = mapAttrsToList (key: value: "${key}=${value}") (default // cfg.extraConfig);
content = concatStringsSep "\n" lines;
file = pkgs.writeText "nagios.cfg" content;
validated = pkgs.runCommand "nagios-checked.cfg" {preferLocalBuild=true;} ''
cp ${file} nagios.cfg
# nagios checks the existence of /var/lib/nagios, but
# it does not exists in the build sandbox, so we fake it
mkdir lib
lib=$(readlink -f lib)
sed -i s@=${nagiosState}@=$lib@ nagios.cfg
${pkgs.nagios}/bin/nagios -v nagios.cfg && cp ${file} $out
'';
defaultCfgFile = if cfg.validateConfig then validated else file;
in
if cfg.mainConfigFile == null then defaultCfgFile else cfg.mainConfigFile;
# Plain configuration for the Nagios web-interface with no
# authentication.
nagiosCGICfgFile = pkgs.writeText "nagios.cgi.conf"
''
main_config_file=${cfg.mainConfigFile}
use_authentication=0
url_html_path=${urlPath}
'';
extraHttpdConfig =
''
ScriptAlias ${urlPath}/cgi-bin ${pkgs.nagios}/sbin
<Directory "${pkgs.nagios}/sbin">
Options ExecCGI
Require all granted
SetEnv NAGIOS_CGI_CONFIG ${cfg.cgiConfigFile}
</Directory>
Alias ${urlPath} ${pkgs.nagios}/share
<Directory "${pkgs.nagios}/share">
Options None
Require all granted
</Directory>
'';
in
{
imports = [
(mkRemovedOptionModule [ "services" "nagios" "urlPath" ] "The urlPath option has been removed as it is hard coded to /nagios in the nagios package.")
];
meta.maintainers = with lib.maintainers; [ symphorien ];
options = {
services.nagios = {
enable = mkEnableOption "<link xlink:href='http://www.nagios.org/'>Nagios</link> to monitor your system or network.";
objectDefs = mkOption {
description = "
A list of Nagios object configuration files that must define
the hosts, host groups, services and contacts for the
network that you want Nagios to monitor.
";
type = types.listOf types.path;
example = literalExample "[ ./objects.cfg ]";
};
plugins = mkOption {
type = types.listOf types.package;
default = with pkgs; [ monitoring-plugins ssmtp mailutils ];
defaultText = "[pkgs.monitoring-plugins pkgs.ssmtp pkgs.mailutils]";
description = "
Packages to be added to the Nagios <envar>PATH</envar>.
Typically used to add plugins, but can be anything.
";
};
mainConfigFile = mkOption {
type = types.nullOr types.package;
default = null;
description = "
If non-null, overrides the main configuration file of Nagios.
";
};
extraConfig = mkOption {
type = types.attrsOf types.str;
example = {
debug_level = "-1";
debug_file = "/var/log/nagios/debug.log";
};
default = {};
description = "Configuration to add to /etc/nagios.cfg";
};
validateConfig = mkOption {
type = types.bool;
default = pkgs.stdenv.hostPlatform == pkgs.stdenv.buildPlatform;
description = "if true, the syntax of the nagios configuration file is checked at build time";
};
cgiConfigFile = mkOption {
type = types.package;
default = nagiosCGICfgFile;
defaultText = "nagiosCGICfgFile";
description = "
Derivation for the configuration file of Nagios CGI scripts
that can be used in web servers for running the Nagios web interface.
";
};
enableWebInterface = mkOption {
type = types.bool;
default = false;
description = "
Whether to enable the Nagios web interface. You should also
enable Apache (<option>services.httpd.enable</option>).
";
};
virtualHost = mkOption {
type = types.submodule (import ../web-servers/apache-httpd/vhost-options.nix);
example = literalExample ''
{ hostName = "example.org";
adminAddr = "webmaster@example.org";
enableSSL = true;
sslServerCert = "/var/lib/acme/example.org/full.pem";
sslServerKey = "/var/lib/acme/example.org/key.pem";
}
'';
description = ''
Apache configuration can be done by adapting <option>services.httpd.virtualHosts</option>.
See <xref linkend="opt-services.httpd.virtualHosts"/> for further information.
'';
};
};
};
config = mkIf cfg.enable {
users.users.nagios = {
description = "Nagios user ";
uid = config.ids.uids.nagios;
home = nagiosState;
group = "nagios";
};
users.groups.nagios = { };
# This isn't needed, it's just so that the user can type "nagiostats
# -c /etc/nagios.cfg".
environment.etc."nagios.cfg".source = nagiosCfgFile;
environment.systemPackages = [ pkgs.nagios ];
systemd.services.nagios = {
description = "Nagios monitoring daemon";
path = [ pkgs.nagios ] ++ cfg.plugins;
wantedBy = [ "multi-user.target" ];
after = [ "network.target" ];
restartTriggers = [ nagiosCfgFile ];
serviceConfig = {
User = "nagios";
Group = "nagios";
Restart = "always";
RestartSec = 2;
LogsDirectory = "nagios";
StateDirectory = "nagios";
ExecStart = "${pkgs.nagios}/bin/nagios /etc/nagios.cfg";
};
};
services.httpd.virtualHosts = optionalAttrs cfg.enableWebInterface {
${cfg.virtualHost.hostName} = mkMerge [ cfg.virtualHost { extraConfig = extraHttpdConfig; } ];
};
};
}