Class: LunaPark::Notifiers::Log

Inherits:
Object
  • Object
show all
Includes:
Extensions::SeverityLevels
Defined in:
lib/luna_park/notifiers/log.rb,
lib/luna_park/notifiers/log/formatters.rb

Overview

Developers need a tool to help them analyze the application. Mostly they use loggers that display messages in files or in STDOUT. But if you have a lot of microservices, analyzing the logs stored in files on different servers can be a problem. You can use some real-time error tracking and debugging tools such as Bugsnag, Rollbar, etc.

Notifiers are an abstraction that breaks the dependency on a particular implementation of a developer’s tool. Current notifier implement abstraction over ruby logger.

For example output to log file message at json format

# Define logger and output destination file or STDOUT\STDERR
logger   = Logger.new('./log/app.log')

# Set output format and minimum level output level
notifier = LunaPark::Notifiers::Logger.new(logger: logger, format: :json, min_lvl: :debug)
notifier.info 'Answer to the Ultimate Question of Life, the Universe and Everything', hint: '21 * 2'

And you will get to ‘./log/app.log’

I, [2020-06-13T21:53:00.824304 #37992]  INFO -- : {"message":"Answer to the Ultimate Question of Life,
the Universe and Everything","details":{"hint":"21 * 2"}}

Defined Under Namespace

Modules: Formatters

Constant Summary

Constants included from Extensions::SeverityLevels

Extensions::SeverityLevels::LEVELS

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Extensions::SeverityLevels

#debug, #error, #fatal, #info, #min_lvl, #min_lvl=, #unknown, #warning

Constructor Details

#initialize(logger: nil, format: nil, formatter: nil, min_lvl: :debug) ⇒ Log

Create new log notifier

Parameters:

  • logger (defaults to: nil) —

    • Logger which used for output all notify see #logger

  • formatter (defaults to: nil) —

    • Log messages formatter see #formatter

  • format (defaults to: nil) —

    • Formatter name. Deprecated and will be removed in a future version

  • min_lvl (defaults to: :debug) —

    • What level should a message be for it to be processed by a notifier



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# File 'lib/luna_park/notifiers/log.rb', line 65

def initialize(logger: nil, format: nil, formatter: nil, min_lvl: :debug)
  @logger      = logger || self.class.default_logger
  @formatter   = formatter || Formatters::SINGLE
  # @todo Remove format param in the future version
  unless format.nil?
    @formatter = formatter_by_name(format)
    warn 'warn [DEPRECATION] `format` parameter is deprecated, use `formatter` instead'
  end
  self.min_lvl = min_lvl
end

Instance Attribute Details

#formatter ⇒ Object (readonly)

Callable object to format log messages.

pretty_formatter = ->(klass, message, details) { “#klass - #message - #details” } notifier = LunaPark::Notifiers::Log.new(formatter: pretty_formatter) notifier.info(‘You hear’, dog: ‘wow’, cats: ‘mow’, timmy: ‘mow’)

> I, [2022-09-29T10:51:15.753646 #28763] INFO – : String - You hear - :cats=>{:chloe=>“mow”, :timmy=>“mow”}



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# File 'lib/luna_park/notifiers/log.rb', line 39

def formatter
  @formatter
end

#logger ⇒ Object (readonly)

Logger which used for output all notify. Should be instance of Logger class. You can define it in two ways.

  • On class class Stderr < LunaPark::Notifier::Log

    logger Logger.new('example.log')

    end

    stderr = Stderr.new stderr.logger # => #<Logger:0x000056445e1e2118 … @filename=“example.log”…

Or in the initialize of the instance

  • On instance stderr = LunaPark::Notifier::Log.new(logger: Logger.new(STDERR)) stderr.logger # => #<Logger:0x000056445e1e2118 … @filename=“example.log”…

At default value is Logger.new(STDOUT)



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# File 'lib/luna_park/notifiers/log.rb', line 57

def logger
  @logger
end

Class Method Details

.default_logger ⇒ Object 



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# File 'lib/luna_park/notifiers/log.rb', line 92

def default_logger
  @default_logger ||= Logger.new(STDOUT)
end

.logger(val) ⇒ Object 



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# File 'lib/luna_park/notifiers/log.rb', line 88

def logger(val)
  @default_logger = val
end

Instance Method Details

#post(msg, lvl: :error, **details) ⇒ Object

Send a notification to the log.

Parameters:

  • msg —

    • Message object, usual String or Exception

  • lvl (Symbol) (defaults to: :error) —

    • Level of current message, can be :debug, :info, :warning, :error, :fatal or :unknown

  • details (Hash) —

    • Any another details for current message



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# File 'lib/luna_park/notifiers/log.rb', line 81

def post(msg, lvl: :error, **details)
  severity = severity(lvl)
  message  = serialize(msg, details)
  logger.add severity, message
end