Rails のログを構造化するやつ

log_subscriber.rb

module MyApp
  class LogSubscriber < ActiveSupport::LogSubscriber
    INTERNAL_PARAMS = %w(controller action format _method only_path)
    IGNORE_PAYLOAD_NAMES = ["SCHEMA", "EXPLAIN"]

    class << self
      attr_accessor :logger
    end

    def registry
      Thread.current[:myapp_log_subscriber_registry] ||= {}
    end

    def reset_registry
      reg = registry.dup
      registry.clear
      reg
    end

    def render_bind(column, value)
      if column
        if column.binary?
          # This specifically deals with the PG adapter that casts bytea columns into a Hash.
          value = value[:value] if value.is_a?(Hash)
          value = value ? "<#{value.bytesize} bytes of binary data>" : "<NULL binary data>"
        end

        [column.name, value]
      else
        [nil, value]
      end
    end

    def sql(event)
      payload = event.payload
      return if IGNORE_PAYLOAD_NAMES.include?(payload[:name])

      query = {}
      query[:sql] = payload[:sql]
      query[:binds] = payload[:binds].map { |col, v| render_bind(col, v) }
      query[:name] = payload[:name]
      query[:duration] = event.duration

      (registry[:queries] ||= []) << query
    end

    def process_action(event)
      payload = event.payload

      registry[:method] = payload[:method]
      registry[:path] = payload[:path]
      registry[:format] = payload[:format]
      registry[:params] = payload[:params].except(*INTERNAL_PARAMS)
      registry[:controller] = payload[:controller]
      registry[:action] = payload[:action]
      registry[:status] = payload[:status]
      registry[:view_runtime] = payload[:view_runtime]
      registry[:db_runtime] = payload[:db_runtime]

      info reset_registry
    end

    def logger
      MyApp::LogSubscriber.logger.presence || Rails.logger
    end
  end
end

MyApp::LogSubscriber.attach_to :action_controller
MyApp::LogSubscriber.attach_to :active_record