Rails Log Silencer Rack Middleware

After enabling debug logging on some Rails apps at work, I found the logs were getting filled up by health checks. So I wrote this simple rack middleware to silence the logs:

# lib/log_silencer.rb
class LogSilencer
  def initialize(app, opts = {})
    @silenced = opts.delete(:silenced)
    @app = app
  end

  def call(env)
    if env['X-SILENCE-LOGGER'] || @silenced.match(env['PATH_INFO'])
      Rails.logger.silence do
        @app.call(env)
      end
    else
      @app.call(env)
    end
  end
end

I was inspired by a stackoverflow answer, but wanted to improve on it. It's configured with the following in the config/application.rb:

# config/application.rb
require 'log_silencer'
config.middleware.insert_before Rails::Rack::Logger,
  LogSilencer,
  silenced: /^\/options/

The silenced: key takes a RegEx to match on the path. In this case, I want to silence any requests to a /options path.

The #silence method on logger is a Rails addition. So if you're using Rails 4+ you have to make sure to use the ActiveSupport::Logger logger.

Donald Plummer's Blog

Rails Log Silencer Rack Middleware