ADD TO GEMFILE
gem 'logstash-logger'

ADD TO <environment>.rb
  config.logstash.type = :file
  config.logstash.path = "log/logstash_#{Rails.env}.log"

IF U HAVE SIDEKIQ ADD TO ADD TO <environment>.rb
Sidekiq.configure_server do
  Sidekiq::Logging.logger = LogStashLogger.new(type: :file,
                                               path: "log/logstash_sidekiq_#{Rails.env}.log",
                                               sync: true)
  Sidekiq::Logging.logger.level = Logger::INFO
  Rails.logger = Sidekiq::Logging.logger
end

READ HOW TO ADD CUSTOM FIELDS HERE https://github.com/dwbutler/logstash-logger#custom-log-fields