grape_logging

Installation

Add this line to your application's Gemfile:

gem 'grape_logging'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install grape_logging

Basic Usage

Include the middleware in your api

class MyAPI < Grape::API
  use GrapeLogging::Middleware::RequestLogger, logger: logger
end

Features

Log Format

With the default configuration you will get nice log message

[2015-04-16 12:52:12 +0200] INFO -- 200 -- total=2.06 db=0.36 -- PATCH /your_app/endpoint params={"some_param"=>{"value_1"=>"123", "value_2"=>"456"}}

If you prefer some other format I strongly encourage you to do pull request with new formatter class ;)

You can change the formatter like so

class MyAPI < Grape::API
  use GrapeLogging::Middleware::RequestLogger, logger: logger, format: MyFormatter.new
end

Customising What Is Logged

You can include logging of other parts of the request / response cycle by including subclasses of GrapeLogging::Loggers::Base

class MyAPI < Grape::API
  use GrapeLogging::Middleware::RequestLogger,
    logger: logger,
    include: [ GrapeLogging::Loggers::Response.new,
               GrapeLogging::Loggers::DatabaseTime.new,
               GrapeLogging::Loggers::FilterParameters.new ]
end

The FilterParameters logger will filter out sensitive parameters from your logs. If mounted inside rails, will use the Rails.application.config.filter_parameters by default. Otherwise, you must specify a list of keys to filter out.

Logging to file and STDOUT

You can to file and STDOUT at the same time, you just need to assign new logger

log_file = File.open('path/to/your/logfile.log', 'a')
log_file.sync = true
logger Logger.new GrapeLogging::MultiIO.new(STDOUT, log_file)

Logging via Rails instrumentation

You can choose to not pass the logger to grape_logging but instead send logs to Rails instrumentation in order to let Rails and its configured Logger do the log job, for example. First, config grape_logging, like that:

class MyAPI < Grape::API
  use GrapeLogging::Middleware::RequestLogger,
    instrumentation_key: 'grape_key',
    include: [ GrapeLogging::Loggers::Response.new,
               GrapeLogging::Loggers::DatabaseTime.new,
               GrapeLogging::Loggers::FilterParameters.new ]
end

and then add an initializer in your Rails project:

# config/initializers/instrumentation.rb

# Subscribe to grape request and log with Rails.logger
ActiveSupport::Notifications.subscribe('grape_key') do |name, starts, ends, notification_id, payload|
  Rails.logger.info payload
end

The idea come from here: https://gist.github.com/teamon/e8ae16ffb0cb447e5b49

There's some advantages to use this method:

• You could use a logger that does not implement the formatter=.
  Defaults Rails 3 (ActiveSupport::BufferedLogger) does not implement it.
  The Logging gem (https://github.com/TwP/logging) does not implement it neither.

• If you use a logger that already format logs (as the Logging gem), the logs will be formatted by your logger.

Logging exceptions

If you want to log exceptions you can do it like this

class MyAPI < Grape::API
  rescue_from :all do |e|
    MyAPI.logger.error e
    #do here whatever you originally planned to do :)
  end
end

Development

After checking out the repo, run bin/setup to install dependencies. Then, run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release to create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

1. Fork it ( https://github.com/aserafin/grape_logging/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request