# frozen_string_literal: true require "benchmark" require "rack" require "prometheus/client" require "prometheus/middleware/exporter" require "sidekiq" require "sidekiq/api" require "webrick" begin require "sidekiq/ent" rescue LoadError end module SidekiqPrometheus class << self # @return [Hash] Preset labels applied to every registered metric attr_accessor :preset_labels # @return [Hash{Symbol => Array}] Custom labels applied to specific metrics attr_accessor :custom_labels # @return [Array] Custom metrics that will be registered on setup. # @example # [ # { # name: :metric_name, # type: :prometheus_metric_type, # docstring: 'Description of the metric', # preset_labels : { label: 'value' }, # } # ] # @note Each element of the array is a hash and must have the required keys: `:name`, `:type`, and `:docstring`. # The values for `:name` and `:type` should be symbols and `:docstring` should be a string. # `preset_labels` is optional and, if used, must be a hash of labels that will be included on every instance of this metric. attr_accessor :custom_metrics # @return [Boolean] Setting to control enabling/disabling GC metrics. Default: true attr_accessor :gc_metrics_enabled # @return [Boolean] Setting to control enabling/disabling global metrics. Default: true attr_accessor :global_metrics_enabled # @return [Boolean] Setting to control enabling/disabling periodic metrics. Default: true attr_accessor :periodic_metrics_enabled # @return [Integer] Interval in seconds to record metrics. Default: 30 attr_accessor :periodic_reporting_interval # @return [Boolean] Setting to control enabling/disabling the metrics server. Default: true attr_accessor :metrics_server_enabled # @return [String] Host on which the metrics server will listen. Default: localhost attr_accessor :metrics_host # @return [Integer] Port on which the metrics server will listen. Default: 9357 attr_accessor :metrics_port # @return [Boolean] When set to false will silence the metric server access logs. Default: true attr_accessor :metrics_server_logger_enabled # Override the default Prometheus::Client # @return [Prometheus::Client] attr_writer :client # Orverride the default Prometheus Metric Registry # @return [Prometheus::Client::Registry] attr_writer :registry # @private attr_writer :setup_complete end self.gc_metrics_enabled = true self.periodic_metrics_enabled = true self.global_metrics_enabled = true self.periodic_reporting_interval = 30 self.metrics_server_enabled = true self.metrics_host = "localhost" self.metrics_port = 9359 self.metrics_server_logger_enabled = true self.custom_labels = {} self.custom_metrics = [] module_function ## # @return Prometheus::Client def client @client ||= Prometheus::Client end ## # Configure SidekiqPrometheus and setup for reporting # @example # SidekiqPrometheus.configure do |config| # config.preset_labels = { service: 'images_api' } # config.custom_labels = { sidekiq_job_count: [:custom_label_1, :custom_label_2] } } # config.gc_metrics_enabled = true # end def configure yield self setup end # Helper method for +gc_metrics_enabled+ configuration setting # @return [Boolean] defaults to true def gc_metrics_enabled? gc_metrics_enabled end ## # Helper method for +global_metrics_enabled+ configuration setting # Requires +Sidekiq::Enterprise+ as it uses the leader election functionality # @return [Boolean] defaults to true if +Sidekiq::Enterprise+ is available def global_metrics_enabled? Object.const_defined?("Sidekiq::Enterprise") && global_metrics_enabled end ## # Helper method for +periodic_metrics_enabled+ configuration setting # Requires +Sidekiq::Enterprise+ as it uses the leader election functionality # @return [Boolean] defaults to true if +Sidekiq::Enterprise+ is available def periodic_metrics_enabled? periodic_metrics_enabled end ## # Helper method for +metrics_server_enabled+ configuration setting # @return [Boolean] defaults to true def metrics_server_enabled? metrics_server_enabled end ## # Helper method for +metrics_server_logger_enabled+ configuration setting # @return [Boolean] defaults to true def metrics_server_logger_enabled? metrics_server_logger_enabled end ## # Get a metric from the registry # @param metric [Symbol] name of metric to fetch # @return [Prometheus::Client::Metric] def [](metric) registry.get(metric.to_sym) end class << self alias_method :configure!, :configure alias_method :get, :[] end ## # Prometheus client metric registry # @return [Prometheus::Client::Registry] def registry @registry ||= client::Registry.new end ## # Register custom metrics # Internal method called by +setup+. This method should not be called from application code in most cases. def register_custom_metrics return if custom_metrics.empty? raise SidekiqPrometheus::Error, "custom_metrics is not an array." unless custom_metrics.is_a?(Array) SidekiqPrometheus::Metrics.register_metrics(custom_metrics) end ## # register metrics and instrument sidekiq def setup return false if @setup_complete SidekiqPrometheus::Metrics.register_sidekiq_job_metrics SidekiqPrometheus::Metrics.register_sidekiq_gc_metric if gc_metrics_enabled? SidekiqPrometheus::Metrics.register_sidekiq_worker_gc_metrics if gc_metrics_enabled? && periodic_metrics_enabled? register_custom_metrics sidekiq_setup self.setup_complete = true end ## # Add Prometheus instrumentation to sidekiq def sidekiq_setup Sidekiq.configure_server do |config| config.server_middleware do |chain| chain.add SidekiqPrometheus::JobMetrics end if periodic_metrics_enabled? config.on(:startup) { SidekiqPrometheus::PeriodicMetrics.reporter(config).start } config.on(:shutdown) { SidekiqPrometheus::PeriodicMetrics.reporter(config).stop } end if metrics_server_enabled? config.on(:startup) { SidekiqPrometheus.metrics_server } config.on(:shutdown) { SidekiqPrometheus.metrics_server.kill } end end end ## # Start a new Prometheus exporter in a new thread. # Will listen on SidekiqPrometheus.metrics_host and # SidekiqPrometheus.metrics_port def metrics_server opts = { Port: SidekiqPrometheus.metrics_port, Host: SidekiqPrometheus.metrics_host } unless metrics_server_logger_enabled? opts[:Logger] = WEBrick::Log.new("/dev/null") opts[:AccessLog] = [] end @_metrics_server ||= Thread.new do Rack::Handler::WEBrick.run( Rack::Builder.new { use Prometheus::Middleware::Exporter, registry: SidekiqPrometheus.registry run ->(_) { [301, {"Location" => "/metrics"}, []] } }, **opts ) end end end class SidekiqPrometheus::Error < StandardError; end require "sidekiq_prometheus/job_metrics" require "sidekiq_prometheus/metrics" require "sidekiq_prometheus/periodic_metrics" require "sidekiq_prometheus/version"