Class: Logtail::Logger

Inherits:
Logger
  • Object
show all
Defined in:
lib/logtail/logger.rb

Overview

The Logtail Logger behaves exactly like the standard Ruby ‘::Logger`, except that it supports a transparent API for logging structured data and events.

Examples:

Basic logging

logger.info "Payment rejected for customer #{customer_id}"

Logging an event

logger.info "Payment rejected", payment_rejected: {customer_id: customer_id, amount: 100}

Defined Under Namespace

Classes: AugmentedFormatter, Formatter, JSONFormatter, MessageOnlyFormatter, PassThroughFormatter

Instance Method Summary collapse

Constructor Details

#initialize(*io_devices_and_loggers) ⇒ Logger

Creates a new Logtail::Logger instance where the passed argument is an IO device. That is, anything that responds to ‘#write` and `#close`.

Note, this method does not accept the same arguments as the standard Ruby ‘::Logger`. The Ruby `::Logger` accepts additional options controlling file rotation if the first argument is a file name. This is a design flaw that Logtail does not assume. Logging to a file, or multiple IO devices is demonstrated in the examples below.

Examples:

Logging to STDOUT

logger = Logtail::Logger.new(STDOUT)

Logging to the Logtail HTTP device

http_device = Logtail::LogDevices::HTTP.new("my-logtail-source-token")
logger = Logtail::Logger.new(http_device)

Logging to a file (with rotation)

file_device = Logger::LogDevice.new("path/to/file.log")
logger = Logtail::Logger.new(file_device)

Logging to a file and the Logtail HTTP device (multiple log devices)

http_device = Logtail::LogDevices::HTTP.new("my-logtail-source-token")
file_logger = ::Logger.new("path/to/file.log")
logger = Logtail::Logger.new(http_device, file_logger)


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# File 'lib/logtail/logger.rb', line 155

def initialize(*io_devices_and_loggers)
  if io_devices_and_loggers.size == 0
    raise ArgumentError.new("At least one IO device or Logger must be provided when " +
      "instantiating a Logtail::Logger. Ex: Logtail::Logger.new(STDOUT).")
  end

  @extra_loggers = io_devices_and_loggers[1..-1].collect do |obj|
    if is_a_logger?(obj)
      obj
    else
      self.class.new(obj)
    end
  end

  io_device = io_devices_and_loggers[0]

  super(io_device)

  # Ensure we sync STDOUT to avoid buffering
  if io_device.respond_to?(:"sync=")
    io_device.sync = true
  end

  # Set the default formatter. The formatter cannot be set during
  # initialization, and can be changed with #formatter=.
  if io_device.is_a?(LogDevices::HTTP)
    self.formatter = PassThroughFormatter.new
  elsif Config.instance.development? || Config.instance.test?
    self.formatter = MessageOnlyFormatter.new
  else
    self.formatter = JSONFormatter.new
  end

  self.level = environment_level

  after_initialize if respond_to?(:after_initialize)

  Logtail::Config.instance.debug { "Logtail::Logger instantiated, level: #{level}, formatter: #{formatter.class}" }

  @initialized = true

  at_exit { self.close }
end

Instance Method Details

#add(severity, message = nil, progname = nil, &block) ⇒ Object

Patch to ensure that the #level method is used instead of ‘@level`. This is required because of Rails’ monkey patching on Logger via ‘::LoggerSilence`.



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# File 'lib/logtail/logger.rb', line 226

def add(severity, message = nil, progname = nil, &block)
  return true if @logdev.nil? || (severity || UNKNOWN) < level

  @extra_loggers.each do |logger|
    logger.add(severity, message, progname, &block)
  end

  super
end

#formatter=(value) ⇒ Object

Note:

The formatter cannot be changed if you are using the HTTP logger backend.

Sets a new formatted on the logger.



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# File 'lib/logtail/logger.rb', line 202

def formatter=(value)
  if @initialized && @logdev && @logdev.dev.is_a?(Logtail::LogDevices::HTTP) && !value.is_a?(PassThroughFormatter)
    raise ArgumentError.new("The formatter cannot be changed when using the " +
      "Logtail::LogDevices::HTTP log device. The PassThroughFormatter must be used for proper " +
      "delivery.")
  end

  super
end

#level=(value) ⇒ Object 



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# File 'lib/logtail/logger.rb', line 212

def level=(value)
  if value.is_a?(Symbol)
    value = level_from_symbol(value)
  end
  super
end

#with_context(context, &block) ⇒ Object 



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# File 'lib/logtail/logger.rb', line 220

def with_context(context, &block)
  Logtail::CurrentContext.with(context, &block)
end