Ougai

A JSON logger is compatible with bunyan for Node.js

Installation

Add this line to your application’s Gemfile:

gem 'ougai'

And then execute:

$ bundle

Or install it yourself as:

$ gem install ougai

Usage

Ougai::Logger is sub-class of original Logger in Ruby.

require 'rubygems'
require 'ougai'

logger = Ougai::Logger.new(STDOUT)

log only a message

logger.info('Information!')

{"name":"main","hostname":"mint","pid":14607,"level":30,"time":"2016-10-16T22:26:48.835+09:00","v":0,"msg":"Information!"}

log only a data

logger.info({
  msg: 'Request', method: 'GET', path: '/login',
  format: 'html', controller: 'LoginController',
  action: 'new', status: 200
})
logger.debug(user: { name: 'Taro', age: 19 })

{"name":"main","hostname":"mint","pid":9044,"level":30,"time":"2016-10-28T17:58:53.668+09:00","v":0,"msg":"Request","method":"GET","path":"/login","format":"html","controller":"LoginController","action":"new","status":200}
{"name":"main","hostname":"mint","pid":9044,"level":20,"time":"2016-10-28T17:58:53.668+09:00","v":0,"msg":"No message","user":{"name":"Taro","age":19}}

If a data does not contain msg field, msg is set default_message attribute value of a Logger. its default is ‘No message’.

logger.default_message = 'User dump'
logger.debug(user: { name: 'Taro', age: 19 })

{"name":"main","hostname":"mint","pid":9303,"level":20,"time":"2016-10-28T18:03:50.118+09:00","v":0,"msg":"User dump","user":{"name":"Taro","age":19}}

log only an exception

begin
  raise StandardError, 'some error'
rescue =&gt; ex
  logger.error(ex)
end

{"name":"main","hostname":"mint","pid":4422,"level":50,"time":"2016-10-22T13:05:02.989+09:00","v":0,"msg":"some error","err":{"name":"StandardError","message":"some error","stack":"main.rb:24:in `'"}}

log with a message and custom data

logger.debug('Debugging', data_id: 1, data_flag: true)
logger.debug('Debug!', custom_data: { id: 1, name: 'something' })

{"name":"main","hostname":"mint","pid":14607,"level":20,"time":"2016-10-16T22:26:48.836+09:00","v":0,"msg":"Debugging","custom_data":{"id":1,"name":"something"}}
{"name":"main","hostname":"mint","pid":14607,"level":20,"time":"2016-10-16T22:26:48.836+09:00","v":0,"msg":"Debug!","data_id":1,"data_flag":true}

log with a message and an exception

begin
  raise StandardError, 'fatal error'
rescue =&gt; ex
  logger.fatal('Unexpected!', ex)
end

{"name":"main","hostname":"mint","pid":14607,"level":60,"time":"2016-10-16T22:26:48.836+09:00","v":0,"msg":"Unexpected!","err":{"name":"StandardError","message":"fatal error","stack":"main.rb:12:in `'"}}

log with an exception and custom data

begin
  raise StandardError, 'some error'
rescue =&gt; ex
  logger.error(ex, error_id: 999)
end

{"name":"main","hostname":"mint","pid":13962,"level":50,"time":"2016-10-28T23:44:52.144+09:00","v":0,"error_id":999,"err":{"name":"StandardError","message":"some error","stack":"main.rb:40:in `'"}}

log with a message, an exception and custom data

begin
  1 / 0
rescue =&gt; ex
  logger.error('Caught error', ex, reason: 'zero spec')
end

{"name":"main","hostname":"mint","pid":14607,"level":50,"time":"2016-10-16T22:26:48.836+09:00","v":0,"msg":"Caught error","err":{"name":"ZeroDivisionError","message":"divided by 0","stack":"main.rb:18:in `/'\n ...'"},"reason":"zero spec"}

View log by node-bunyan

Install bunyan via NPM

$ npm install -g bunyan

Pass a log file to command bunyan

$ bunyan output.log
[2016-10-16T22:26:48.835+09:00]  INFO: main/14607 on mint: Info message!
[2016-10-16T22:26:48.836+09:00] DEBUG: main/14607 on mint: Debugging (data_id=1, data_flag=true)
[2016-10-16T22:26:48.836+09:00] DEBUG: main/14607 on mint: Debug!
    custom_data: {
      "id": 1,
      "name": "something"
    }
[2016-10-16T22:26:48.836+09:00] FATAL: main/14607 on mint: Unexpected!
    main.rb:12:in `'
[2016-10-16T22:26:48.836+09:00] ERROR: main/14607 on mint: Caught error (reason="z
    main.rb:18:in `/'
      main.rb:18:in `'

License

MIT

Modules

Classes