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 <http://prometheus.io/>
       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;
           my $prom = Promethus::Tiny->new(default_labels => { my_label => "frob" });

       If you pass a "default_labels" key to the constructor, these labels will be included in
       every metric created on this object.

METHODS

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

       Set the value for the named metric. The labels hashref is optional. The timestamp
       (milliseconds since epoch) is optional, but requires labels to be provided to use. An
       empty hashref will work in the case of no labels.

       Trying to set a metric to a non-numeric value will emit a warning and the metric will be
       set to zero.

   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.

       Trying to add a non-numeric value to a metric will emit a warning and 0 will be added
       instead (this will still create the metric if it didn't exist, and will update timestamps
       etc).

   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 })

   clear
           $prom->clear;

       Remove all stored metric values. Metric metadata (set by "declare") is preserved.

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

       Record a histogram observation. The labels hashref is optional.

       You should declare your metric beforehand, using the "buckets" key to set the buckets you
       want to use. If you don't, the following buckets will be used.

           [ 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 ]

   enum_set
           $prom->enum_set($name, $value, { labels }, [timestamp])

       Set an enum value for the named metric. The labels hashref is optiona. The timestamp is
       optional.

       You should declare your metric beforehand, using the "enum" key to set the label to use
       for the enum value, and the "enum_values" key to list the possible values for the enum.

   declare
           $prom->declare($name, help => $help, type => $type, buckets => [...])

       "Declare" a metric by associating metadata with it. Valid keys are:

       "help"
           Text describing the metric. This will appear in the formatted output sent to
           Prometheus.

       "type"
           Type of the metric, typically "gauge" or "counter".

       "buckets"
           For "histogram" metrics, an arrayref of the buckets to use. See "histogram_observe".

       "enum"
           For "enum" metrics, the name of the label to use for the enum value. See "enum_set".

       "enum_values"
           For "enum" metrics, the possible values the enum can take. See "enum_set".

       Declaring a already-declared metric will work, but only if the metadata keys and values
       match the previous call. If not, "declare" will throw an exception.

   format
           my $metrics = $prom->format

       Output the stored metrics, values, help text and types in the Prometheus exposition format
       <https://github.com/prometheus/docs/blob/master/content/docs/instrumenting/exposition_formats.md>.

   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>

CONTRIBUTORS

       •   ben hengst <ben.hengst@dreamhost.com>

       •   Danijel Tasov <data@consol.de>

       •   Michael McClimon <michael@mcclimon.org>

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.