out_color_stdout.rb

/*
 * Place here: ~/.rvm/gems/ruby-2.4.1/gems/fluentd-1.6.0/lib/fluent/plugin/out_color_stdout.rb
 * Run this: gem install awesome_print
 */

require 'fluent/plugin/output'
require 'awesome_print'

module Fluent::Plugin
  class StdoutOutput < Output
    Fluent::Plugin.register_output('color_stdout', self)

    helpers :inject, :formatter, :compat_parameters

    DEFAULT_LINE_FORMAT_TYPE = 'stdout'
    DEFAULT_FORMAT_TYPE = 'json'

    config_section :buffer do
      config_set_default :chunk_keys, ['tag']
      config_set_default :flush_at_shutdown, true
      config_set_default :chunk_limit_size, 10 * 1024
    end

    config_section :format do
      config_set_default :@type, DEFAULT_LINE_FORMAT_TYPE
      config_set_default :output_type, DEFAULT_FORMAT_TYPE
    end

    def prefer_buffered_processing
      false
    end

    def multi_workers_ready?
      true
    end

    attr_accessor :formatter

    def configure(conf)
      compat_parameters_convert(conf, :inject, :formatter)

      super

      @formatter = formatter_create
    end

    def process(tag, es)
      es = inject_values_to_event_stream(tag, es)
      es.each {|time,record|
        $log.write(format(tag, time, record))
      }
      $log.flush
    end

    def color(level)
      {
        "error" => :red,
        "warning" => :yellow,
        "success" => :green,
        "info" => :blue,
        "debug" => :gray,
        "trace" => :to_s,
      }[level] || :to_s
    end

    def format(tag, time, record)
      record = inject_values_to_record(tag, time, record)
      col = color(record['level'])
      @formatter.format(tag, time, record).chomp.send(col) + "\n"
    end

    def write(chunk)
      chunk.write_to($log)
    end
  end
end