Class: Lumberjack::JsonDevice

Inherits:
Device
  • Object
show all
Defined in:
lib/lumberjack_json_device.rb

Overview

This Lumberjack device logs output to another device as JSON formatted text with one document per line.

The mapping parameter can be used to define the JSON data structure. To define the structure pass in a hash with key indicating the log entry field and the value indicating the JSON document key.

The standard entry fields are mapped with the following keys:

  • :time

  • :severity

  • :progname

  • :pid

  • :message

  • :tags

Any additional keys will be pulled from the tags. If any of the standard keys are missing or have a nil mapping, the entry field will not be included in the JSON output.

You can create a nested JSON structure by specifying an array as the JSON key.

Constant Summary collapse

DEFAULT_MAPPING = 
{
  time: true,
  severity: true,
  progname: true,
  pid: true,
  message: true,
  tags: true
}.freeze
DEFAULT_TIME_FORMAT = 
"%Y-%m-%dT%H:%M:%S.%6N%z"

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(stream_or_device, mapping: DEFAULT_MAPPING, formatter: nil, datetime_format: nil) ⇒ JsonDevice

Returns a new instance of JsonDevice.



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# File 'lib/lumberjack_json_device.rb', line 42

def initialize(stream_or_device, mapping: DEFAULT_MAPPING, formatter: nil, datetime_format: nil)
  @mutex = Mutex.new

  if stream_or_device.is_a?(Device)
    @device = stream_or_device
  else
    @device = Writer.new(stream_or_device)
  end

  self.mapping = mapping

  if formatter
    @formatter = formatter
  else
    @formatter = default_formatter
    datetime_format = DEFAULT_TIME_FORMAT if datetime_format.nil?
  end
  add_datetime_formatter!(datetime_format) unless datetime_format.nil?
end

Instance Attribute Details

#formatter ⇒ Object

Returns the value of attribute formatter.



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# File 'lib/lumberjack_json_device.rb', line 39

def formatter
  @formatter
end

#mapping ⇒ Object

Returns the value of attribute mapping.



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# File 'lib/lumberjack_json_device.rb', line 40

def mapping
  @mapping
end

Instance Method Details

#datetime_format ⇒ Object 



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# File 'lib/lumberjack_json_device.rb', line 73

def datetime_format
  @datetime_format
end

#datetime_format=(format) ⇒ Object

Set the datetime format for the log timestamp.



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# File 'lib/lumberjack_json_device.rb', line 78

def datetime_format=(format)
  add_datetime_formatter!(format)
end

#entry_as_json(entry) ⇒ Object

Convert a Lumberjack::LogEntry to a Hash using the specified field mapping.



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# File 'lib/lumberjack_json_device.rb', line 115

def entry_as_json(entry)
  data = {}
  set_attribute(data, @time_key, entry.time) unless @time_key.nil?
  set_attribute(data, @severity_key, entry.severity_label) unless @severity_key.nil?
  set_attribute(data, @progname_key, entry.progname) unless @progname_key.nil?
  set_attribute(data, @pid_key, entry.pid) unless @pid_key.nil?
  set_attribute(data, @message_key, entry.message) unless @message_key.nil?

  tags = entry.tags
  if @custom_keys.size > 0
    tags = (tags.nil? ? {} : tags.dup)
    @custom_keys.each do |name, key|
      set_attribute(data, key, tags.delete(name.to_s))
    end
  end

  unless @tags_key.nil?
    tags ||= {}
    set_attribute(data, @tags_key, tags)
  end

  data = @formatter.format(data) if @formatter
  data
end

#flush ⇒ Object 



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# File 'lib/lumberjack_json_device.rb', line 69

def flush
  @device.flush
end

#map(field_mapping) ⇒ Object 



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# File 'lib/lumberjack_json_device.rb', line 106

def map(field_mapping)
  new_mapping = {}
  field_mapping.each do |key, value|
    new_mapping[key.to_sym] = value
  end
  self.mapping = mapping.merge(new_mapping)
end

#write(entry) ⇒ Object 



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# File 'lib/lumberjack_json_device.rb', line 62

def write(entry)
  return if entry.message.nil? || entry.message == ""
  data = entry_as_json(entry)
  json = MultiJson.dump(data)
  @device.write(json)
end