nixpkgs/nixos/modules/services/monitoring/prometheus/alertmanager.nix
2020-04-13 18:39:51 +02:00

188 lines
6.2 KiB
Nix

{ config, pkgs, lib, ... }:
with lib;
let
cfg = config.services.prometheus.alertmanager;
mkConfigFile = pkgs.writeText "alertmanager.yml" (builtins.toJSON cfg.configuration);
checkedConfig = file: pkgs.runCommand "checked-config" { buildInputs = [ cfg.package ]; } ''
ln -s ${file} $out
amtool check-config $out
'';
alertmanagerYml = let
yml = if cfg.configText != null then
pkgs.writeText "alertmanager.yml" cfg.configText
else mkConfigFile;
in checkedConfig yml;
cmdlineArgs = cfg.extraFlags ++ [
"--config.file /tmp/alert-manager-substituted.yaml"
"--web.listen-address ${cfg.listenAddress}:${toString cfg.port}"
"--log.level ${cfg.logLevel}"
"--storage.path /var/lib/alertmanager"
(toString (map (peer: "--cluster.peer ${peer}:9094") cfg.clusterPeers))
] ++ (optional (cfg.webExternalUrl != null)
"--web.external-url ${cfg.webExternalUrl}"
) ++ (optional (cfg.logFormat != null)
"--log.format ${cfg.logFormat}"
);
in {
imports = [
(mkRemovedOptionModule [ "services" "prometheus" "alertmanager" "user" ] "The alertmanager service is now using systemd's DynamicUser mechanism which obviates a user setting.")
(mkRemovedOptionModule [ "services" "prometheus" "alertmanager" "group" ] "The alertmanager service is now using systemd's DynamicUser mechanism which obviates a group setting.")
(mkRemovedOptionModule [ "services" "prometheus" "alertmanagerURL" ] ''
Due to incompatibility, the alertmanagerURL option has been removed,
please use 'services.prometheus2.alertmanagers' instead.
'')
];
options = {
services.prometheus.alertmanager = {
enable = mkEnableOption "Prometheus Alertmanager";
package = mkOption {
type = types.package;
default = pkgs.prometheus-alertmanager;
defaultText = "pkgs.alertmanager";
description = ''
Package that should be used for alertmanager.
'';
};
configuration = mkOption {
type = types.nullOr types.attrs;
default = null;
description = ''
Alertmanager configuration as nix attribute set.
'';
};
configText = mkOption {
type = types.nullOr types.lines;
default = null;
description = ''
Alertmanager configuration as YAML text. If non-null, this option
defines the text that is written to alertmanager.yml. If null, the
contents of alertmanager.yml is generated from the structured config
options.
'';
};
logFormat = mkOption {
type = types.nullOr types.str;
default = null;
description = ''
If set use a syslog logger or JSON logging.
'';
};
logLevel = mkOption {
type = types.enum ["debug" "info" "warn" "error" "fatal"];
default = "warn";
description = ''
Only log messages with the given severity or above.
'';
};
webExternalUrl = mkOption {
type = types.nullOr types.str;
default = null;
description = ''
The URL under which Alertmanager is externally reachable (for example, if Alertmanager is served via a reverse proxy).
Used for generating relative and absolute links back to Alertmanager itself.
If the URL has a path portion, it will be used to prefix all HTTP endoints served by Alertmanager.
If omitted, relevant URL components will be derived automatically.
'';
};
listenAddress = mkOption {
type = types.str;
default = "";
description = ''
Address to listen on for the web interface and API. Empty string will listen on all interfaces.
"localhost" will listen on 127.0.0.1 (but not ::1).
'';
};
port = mkOption {
type = types.int;
default = 9093;
description = ''
Port to listen on for the web interface and API.
'';
};
openFirewall = mkOption {
type = types.bool;
default = false;
description = ''
Open port in firewall for incoming connections.
'';
};
clusterPeers = mkOption {
type = types.listOf types.str;
default = [];
description = ''
Initial peers for HA cluster.
'';
};
extraFlags = mkOption {
type = types.listOf types.str;
default = [];
description = ''
Extra commandline options when launching the Alertmanager.
'';
};
environmentFile = mkOption {
type = types.nullOr types.path;
default = null;
example = "/root/alertmanager.env";
description = ''
File to load as environment file. Environment variables
from this file will be interpolated into the config file
using envsubst with this syntax:
<literal>$ENVIRONMENT ''${VARIABLE}</literal>
'';
};
};
};
config = mkMerge [
(mkIf cfg.enable {
assertions = singleton {
assertion = cfg.configuration != null || cfg.configText != null;
message = "Can not enable alertmanager without a configuration. "
+ "Set either the `configuration` or `configText` attribute.";
};
})
(mkIf cfg.enable {
networking.firewall.allowedTCPPorts = optional cfg.openFirewall cfg.port;
systemd.services.alertmanager = {
wantedBy = [ "multi-user.target" ];
after = [ "network-online.target" ];
preStart = ''
${lib.getBin pkgs.envsubst}/bin/envsubst -o "/tmp/alert-manager-substituted.yaml" \
-i "${alertmanagerYml}"
'';
serviceConfig = {
Restart = "always";
StateDirectory = "alertmanager";
DynamicUser = true; # implies PrivateTmp
EnvironmentFile = lib.mkIf (cfg.environmentFile != null) cfg.environmentFile;
WorkingDirectory = "/tmp";
ExecStart = "${cfg.package}/bin/alertmanager" +
optionalString (length cmdlineArgs != 0) (" \\\n " +
concatStringsSep " \\\n " cmdlineArgs);
ExecReload = "${pkgs.coreutils}/bin/kill -HUP $MAINPID";
};
};
})
];
}