class GitLab::Exporter::PrometheusMetrics
Prometheus metrics container
Provides a simple API to `add` metrics and then turn them `to_s` which will just dump all the metrics in prometheus format
The add method also can take any arbitrary amount of labels in a `key: value` format.
Public Class Methods
clear_descriptions()
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# File lib/gitlab_exporter/prometheus.rb, line 28 def clear_descriptions @metric_descriptions = {} end
describe(name, description)
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# File lib/gitlab_exporter/prometheus.rb, line 19 def describe(name, description) @metric_descriptions ||= {} @metric_descriptions[name] = description end
description(name)
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# File lib/gitlab_exporter/prometheus.rb, line 24 def description(name) @metric_descriptions && @metric_descriptions[name] end
new(include_timestamp: true)
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# File lib/gitlab_exporter/prometheus.rb, line 12 def initialize(include_timestamp: true) @metrics = Hash.new { |h, k| h[k] = [] } @quantiles = Hash.new { |h, k| h[k] = [] } @include_timestamp = include_timestamp end
Public Instance Methods
add(name, value, quantile = false, **labels)
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# File lib/gitlab_exporter/prometheus.rb, line 33 def add(name, value, quantile = false, **labels) fail "value '#{value}' must be a number" unless value.is_a?(Numeric) if quantile @quantiles[{ name: name, labels: labels }] << value else @metrics[name] << { value: value, labels: labels, timestamp: (Time.now.to_f * 1000).to_i } end self end
to_s()
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# File lib/gitlab_exporter/prometheus.rb, line 45 def to_s add_quantiles_to_metrics buffer = "" @metrics.each do |name, measurements| buffer << "# HELP #{name} #{self.class.description(name)}\n" if self.class.description(name) measurements.each do |measurement| buffer << name.to_s labels = (measurement[:labels] || {}).map { |label, value| "#{label}=\"#{value}\"" }.join(",") buffer << "{#{labels}}" unless labels.empty? buffer << " #{measurement[:value]}" buffer << " #{measurement[:timestamp]}" if @include_timestamp buffer << "\n" end end buffer end
Private Instance Methods
add_quantiles_to_metrics()
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# File lib/gitlab_exporter/prometheus.rb, line 66 def add_quantiles_to_metrics @quantiles.each do |data, measurements| estimator = Quantile::Estimator.new measurements.each do |value| estimator.observe(value) end estimator.invariants.each do |invariant| data[:labels][:quantile] = "#{(invariant.quantile * 100).to_i}th" add(data[:name], estimator.query(invariant.quantile), **data[:labels]) end end end