nixos/prometheus/pushgateway: add module and test

This commit is contained in:
Bas van Dijk 2019-04-15 23:46:25 +02:00
parent 888f32f32f
commit d1940beb3a
3 changed files with 207 additions and 7 deletions

View file

@ -491,6 +491,7 @@
./services/monitoring/prometheus/default.nix
./services/monitoring/prometheus/alertmanager.nix
./services/monitoring/prometheus/exporters.nix
./services/monitoring/prometheus/pushgateway.nix
./services/monitoring/riemann.nix
./services/monitoring/riemann-dash.nix
./services/monitoring/riemann-tools.nix

View file

@ -0,0 +1,166 @@
{ config, pkgs, lib, ... }:
with lib;
let
cfg = config.services.prometheus.pushgateway;
cmdlineArgs =
opt "web.listen-address" cfg.web.listen-address
++ opt "web.telemetry-path" cfg.web.telemetry-path
++ opt "web.external-url" cfg.web.external-url
++ opt "web.route-prefix" cfg.web.route-prefix
++ optional cfg.persistMetrics ''--persistence.file="/var/lib/${cfg.stateDir}/metrics"''
++ opt "persistence.interval" cfg.persistence.interval
++ opt "log.level" cfg.log.level
++ opt "log.format" cfg.log.format
++ cfg.extraFlags;
opt = k : v : optional (v != null) ''--${k}="${v}"'';
in {
options = {
services.prometheus.pushgateway = {
enable = mkEnableOption "Prometheus Pushgateway";
package = mkOption {
type = types.package;
default = pkgs.prometheus-pushgateway;
defaultText = "pkgs.prometheus-pushgateway";
description = ''
Package that should be used for the prometheus pushgateway.
'';
};
web.listen-address = mkOption {
type = types.nullOr types.str;
default = null;
description = ''
Address to listen on for the web interface, API and telemetry.
<literal>null</literal> will default to <literal>:9091</literal>.
'';
};
web.telemetry-path = mkOption {
type = types.nullOr types.str;
default = null;
description = ''
Path under which to expose metrics.
<literal>null</literal> will default to <literal>/metrics</literal>.
'';
};
web.external-url = mkOption {
type = types.nullOr types.str;
default = null;
description = ''
The URL under which Pushgateway is externally reachable.
'';
};
web.route-prefix = mkOption {
type = types.nullOr types.str;
default = null;
description = ''
Prefix for the internal routes of web endpoints.
Defaults to the path of
<option>services.prometheus.pushgateway.web.external-url</option>.
'';
};
persistence.interval = mkOption {
type = types.nullOr types.str;
default = null;
example = "10m";
description = ''
The minimum interval at which to write out the persistence file.
<literal>null</literal> will default to <literal>5m</literal>.
'';
};
log.level = mkOption {
type = types.nullOr (types.enum ["debug" "info" "warn" "error" "fatal"]);
default = null;
description = ''
Only log messages with the given severity or above.
<literal>null</literal> will default to <literal>info</literal>.
'';
};
log.format = mkOption {
type = types.nullOr types.str;
default = null;
example = "logger:syslog?appname=bob&local=7";
description = ''
Set the log target and format.
<literal>null</literal> will default to <literal>logger:stderr</literal>.
'';
};
extraFlags = mkOption {
type = types.listOf types.str;
default = [];
description = ''
Extra commandline options when launching the Pushgateway.
'';
};
persistMetrics = mkOption {
type = types.bool;
default = false;
description = ''
Whether to persist metrics to a file.
When enabled metrics will be saved to a file called
<literal>metrics</literal> in the directory
<literal>/var/lib/pushgateway</literal>. The directory below
<literal>/var/lib</literal> can be set using
<option>services.prometheus.pushgateway.stateDir</option>.
'';
};
stateDir = mkOption {
type = types.str;
default = "pushgateway";
description = ''
Directory below <literal>/var/lib</literal> to store metrics.
This directory will be created automatically using systemd's
StateDirectory mechanism when
<option>services.prometheus.pushgateway.persistMetrics</option>
is enabled.
'';
};
};
};
config = mkIf cfg.enable {
assertions = [
{
assertion = !hasPrefix "/" cfg.stateDir;
message =
"The option services.prometheus.pushgateway.stateDir" +
" shouldn't be an absolute directory." +
" It should be a directory relative to /var/lib.";
}
];
systemd.services.pushgateway = {
wantedBy = [ "multi-user.target" ];
after = [ "network.target" ];
serviceConfig = {
Restart = "always";
DynamicUser = true;
ExecStart = "${cfg.package}/bin/pushgateway" +
optionalString (length cmdlineArgs != 0) (" \\\n " +
concatStringsSep " \\\n " cmdlineArgs);
StateDirectory = if cfg.persistMetrics then cfg.stateDir else null;
};
};
};
}

View file

@ -3,15 +3,29 @@ import ./make-test.nix {
nodes = {
one = { pkgs, ... }: {
environment.systemPackages = [ pkgs.jq ];
services.prometheus2 = {
enable = true;
scrapeConfigs = [{
job_name = "prometheus";
static_configs = [{
targets = [ "127.0.0.1:9090" ];
labels = { instance = "localhost"; };
}];
}];
scrapeConfigs = [
{
job_name = "prometheus";
static_configs = [
{
targets = [ "127.0.0.1:9090" ];
labels = { instance = "localhost"; };
}
];
}
{
job_name = "pushgateway";
scrape_interval = "1s";
static_configs = [
{
targets = [ "127.0.0.1:9091" ];
}
];
}
];
rules = [
''
groups:
@ -22,6 +36,12 @@ import ./make-test.nix {
''
];
};
services.prometheus.pushgateway = {
enable = true;
persistMetrics = true;
persistence.interval = "1s";
stateDir = "prometheus-pushgateway";
};
};
};
@ -30,5 +50,18 @@ import ./make-test.nix {
$one->waitForUnit("prometheus2.service");
$one->waitForOpenPort(9090);
$one->succeed("curl -s http://127.0.0.1:9090/metrics");
# Let's test if pushing a metric to the pushgateway succeeds
# and whether that metric gets ingested by prometheus.
$one->waitForUnit("pushgateway.service");
$one->succeed(
"echo 'some_metric 3.14' | " .
"curl --data-binary \@- http://127.0.0.1:9091/metrics/job/some_job");
$one->waitUntilSucceeds(
"curl -sf 'http://127.0.0.1:9090/api/v1/query?query=some_metric' " .
"| jq '.data.result[0].value[1]' | grep '\"3.14\"'");
# Let's test if the pushgateway persists metrics to the configured location.
$one->waitUntilSucceeds("test -e /var/lib/prometheus-pushgateway/metrics");
'';
}