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Mojolicious::Plugin::Prometheus - Mojolicious Plugin


# Mojolicious

# Mojolicious::Lite
plugin 'Prometheus';

# Mojolicious::Lite, with custom response buckets (seconds)
plugin 'Prometheus' => { response_buckets => [qw/4 5 6/] };

# You can add your own route to do access control
my $under = app->routes->under('/secret' =>sub {
  my $c = shift;
  return 1 if $c->req->url->to_abs->userinfo eq 'Bender:rocks';
  $c->render(text => 'Authentication required!', status => 401);
  return undef;
plugin Prometheus => {route => $under};


Mojolicious::Plugin::Prometheus is a Mojolicious plugin that exports Prometheus metrics from Mojolicious.

Hooks are also installed to measure requests response time and count requests based on method and HTTP return code.



Create further instrumentation into your application by using this helper which gives access to the Net::Prometheus object. See Net::Prometheus for usage.


Mojolicious::Plugin::Prometheus inherits all methods from Mojolicious::Plugin and implements the following new ones.


$plugin->register($app, \%config);

Register plugin in Mojolicious application.

%config can have:

  • route

    Mojolicious::Routes::Route object to attach the metrics to, defaults to generating a new one for '/'.

    Default: /

  • path

    The path to mount the exporter.

    Default: /metrics

  • prometheus

    Override the Net::Prometheus object. The default is a new singleton instance of Net::Prometheus.

  • namespace, subsystem

    These will be prefixed to the metrics exported.

  • request_buckets

    Override buckets for request sizes histogram.

    Default: (1, 50, 100, 1_000, 10_000, 50_000, 100_000, 500_000, 1_000_000)

  • response_buckets

    Override buckets for response sizes histogram.

    Default: (5, 50, 100, 1_000, 10_000, 50_000, 100_000, 500_000, 1_000_000)

  • duration_buckets

    Override buckets for request duration histogram.

    Default: (0.005, 0.01, 0.025, 0.05, 0.075, 0.1, 0.25, 0.5, 0.75, 1.0, 2.5, 5.0, 7.5, 10) (actually see Net::Prometheus)

  • shm_key

    Key used for shared memory access between workers, see $key in IPc::ShareLite for details.


In addition to exposing the default process metrics that Net::Prometheus already expose this plugin will also expose

  • http_requests_total, request counter partitioned over HTTP method and HTTP response code
  • http_request_duration_seconds, request duration histogram partitioned over HTTP method
  • http_request_size_bytes, request size histogram partitioned over HTTP method
  • http_response_size_bytes, response size histogram partitioned over HTTP method


Vidar Tyldum

(the IPC::ShareLite parts of this code is shamelessly stolen from Mojolicious::Plugin::Status written by Sebastian Riedel and mangled into something that works for me)


Copyright (C) 2018, Vidar Tyldum

This program is free software, you can redistribute it and/or modify it under the terms of the Artistic License version 2.0.