Loga

Description

Loga defines a single log format, logger and middleware logger to faciliate log aggregation.

It provides:

Rack logger middleware to log HTTP requests
Ruby logger

Installation

Add this line to your application's Gemfile:

gem 'loga', git: '[email protected]:FundingCircle/loga.git'

And then execute:

$ bundle

Usage

Loga integrates well with Rails and Sinatra frameworks. It also works in projects using plain Ruby.

Rails applications

In Rails applications initialization and middleware insertion is catered by the Railtie.

# config/environments/production.rb
...
config.loga.configure do |loga|
  # See configuration section
end
...

Ruby and Sinatra/Rack applications

In Ruby applications Loga must be required and configured.

# .../initializers/loga.rb
require 'loga'

Loga.configure do |loga|
  # See configuration section
end
Loga.initialize!

Log requests in Rack applications with Loga middleware.

RequestId and Logger must be inserted early in the middleware chain.

# config.ru
use Loga::Rack::RequestId
use Loga::Rack::Logger, Loga.logger

user Marketplace
run Sinatra::Application

Configuration

Option	Type	Default	Description
host	String	nil	Service hostname. When nil the hostname is computed with `Socket.gethostname`
service_version	String/Symbol	:git	Service version is embedded in every message. When Symbol the version is computed with a strategy.
service_name	String	nil	Service name is embedded in every message
device	IO	nil	The device the logger writes to
sync	Boolean	true	Sync IO
level	Symbol	:info	The level to logger logs at
enabled	Boolean	true	Enable/Disable Loga in Rails

Sample output

# Anywhere in your application
Loga.logger.info('Hello World')

//GELF Output
{
  "version":           "1.1",
  "host":              "example.com",
  "short_message":     "Hello World",
  "timestamp":         1450150205.123,
  "level":             6,
  "_service.name":     "marketplace",
  "_service.version":  "v1.0.0",
  "_tags":             ""
}

Event types

Middleware augment payload with the type key to label events.

event type	description	middleware
request	HTTP request and response	Rack

Caveat

Loga formats timestamps in seconds since UNIX epoch with 3 decimal places for milliseconds. Which is in accordance with GELF 1.1 specification.

Road Map

Consult the milestones.

Contributing

Overview

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

Running tests

This project uses appraisal to run tests against different versions of dependencies (e.g. Rails, Sinatra).

Once you have run bundle, you can install the test dependencies with bundle exec appraisal install.

Run all tests with bundle exec appraisal rspec.

You can run tests for one appraisal with bundle exec appraisal appraisal-name rspec.

With Rack applications prepend RACK_ENV to switch between environments RACK_ENV=production bundle exec appraisal rspec

Refer to the Appraisals file for a complete lists of appraisals.