Rob N ★

NAME

Prometheus::Tiny - A tiny Prometheus client

SYNOPSIS

    use Prometheus::Tiny;

    my $prom = Prometheus::Tiny->new;
    $prom->set('some_metric', 5, { some_label => "aaa" });
    print $prom->format;

DESCRIPTION

Prometheus::Tiny is a minimal metrics client for the Prometheus time-series database.

It does the following things differently to Net::Prometheus:

  • No setup. You don't need to pre-declare metrics to get something useful.

  • Labels are passed in a hash. Positional parameters get awkward.

  • No inbuilt collectors, PSGI apps, etc. Just the metrics.

  • Doesn't know anything about different metric types. You get what you ask for.

These could all be pros or cons, depending on what you need. For me, I needed a compact base that I could back on a shared memory region. See Prometheus::Tiny::Shared for that!

CONSTRUCTOR

new

    my $prom = Prometheus::Tiny->new

METHODS

set

    $prom->set($name, $value, { labels })

Set the value for the named metric. The labels hashref is optional.

add

    $prom->add($name, $amount, { labels })

Add the given amount to the already-stored value (or 0 if it doesn't exist). The labels hashref is optional.

inc

    $prom->inc($name, { labels })

A shortcut for

    $prom->add($name, 1, { labels })

dec

    $prom->dec($name, { labels })

A shortcut for

    $prom->add($name, -1, { labels })

declare

    $prom->declare($name, help => $help, type => $type)

"Declare" a metric by setting its help text or type.

format

    my $metrics = $prom->format

Output the stored metrics, values, help text and types in the Prometheus exposition format.

psgi

    use Plack::Builder
    builder {
      mount "/metrics" => $prom->psgi;
    };

Returns a simple PSGI app that, when hooked up to a web server and called, will return formatted metrics for Prometheus. This is little more than a wrapper around format, namely:

    sub app {
      my $env = shift;
      return [ 200, [ 'Content-Type' => 'text/plain' ], [ $prom->format ] ];
    }

This is just a convenience; if you already have a web server or you want to ship metrics via some other means (eg the Node Exporter's textfile collector), just use format.

SUPPORT

Bugs / Feature Requests

Please report any bugs or feature requests through the issue tracker at https://github.com/robn/Prometheus-Tiny/issues. You will be notified automatically of any progress on your issue.

Source Code

This is open source software. The code repository is available for public review and contribution under the terms of the license.

https://github.com/robn/Prometheus-Tiny

  git clone https://github.com/robn/Prometheus-Tiny.git

AUTHORS

  • Rob N ★ <robn@robn.io>

COPYRIGHT AND LICENSE

This software is copyright (c) 2017 by Rob N ★

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.