Class: StatsD::Instrument::Environment

Inherits:
Object
  • Object
show all
Defined in:
lib/statsd/instrument/environment.rb

Overview

The environment module is used to detect, and initialize the environment in which this library is active. It will use different default values based on the environment.

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(env) ⇒ Environment

Returns a new instance of Environment.



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# File 'lib/statsd/instrument/environment.rb', line 57

def initialize(env)
  @env = env
end

Instance Attribute Details

#env ⇒ Object (readonly)

Returns the value of attribute env.



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# File 'lib/statsd/instrument/environment.rb', line 55

def env
  @env
end

Class Method Details

.default_backend ⇒ StatsD::Instrument::Backend

Instantiates a default backend for the current environment.

Returns:

See Also:



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# File 'lib/statsd/instrument/environment.rb', line 26

def default_backend
  case environment
  when 'production', 'staging'
    StatsD::Instrument::Backends::UDPBackend.new(from_env.statsd_addr, from_env.statsd_implementation)
  when 'test'
    StatsD::Instrument::Backends::NullBackend.new
  else
    StatsD::Instrument::Backends::LoggerBackend.new(StatsD.logger)
  end
end

.environment ⇒ String

Detects the current environment, either by asking Rails, or by inspecting environment variables.

  • Within a Rails application, Rails.env is used.
  • It will check the following environment variables in order: RAILS_ENV, RACK_ENV, ENV.
  • If none of these are set, it will return development

Returns:

  • (String) —

    The detected environment.



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# File 'lib/statsd/instrument/environment.rb', line 18

def environment
  from_env.environment
end

.from_env ⇒ Object 



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# File 'lib/statsd/instrument/environment.rb', line 7

def from_env
  @from_env ||= StatsD::Instrument::Environment.new(ENV)
end

.setup ⇒ void

This method returns an undefined value.

Sets default values for sample rate and logger.

  • Default sample rate is set to the value in the STATSD_SAMPLE_RATE environment variable, or 1.0 otherwise. See StatsD#default_sample_rate
  • StatsD#logger is set to a logger that send output to stderr.

If you are including this library inside a Rails environment, additional initialization will be done as part of the Railtie.



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# File 'lib/statsd/instrument/environment.rb', line 47

def setup
  StatsD.prefix = from_env.statsd_prefix
  StatsD.default_tags = from_env.statsd_default_tags
  StatsD.default_sample_rate = from_env.statsd_sample_rate
  StatsD.logger = Logger.new($stderr)
end

Instance Method Details

#client ⇒ Object 



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# File 'lib/statsd/instrument/environment.rb', line 98

def client
  if env.key?('STATSD_USE_NEW_CLIENT')
    default_client
  else
    StatsD::Instrument::LegacyClient.singleton
  end
end

#default_client ⇒ Object 



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# File 'lib/statsd/instrument/environment.rb', line 106

def default_client
  @default_client ||= StatsD::Instrument::Client.new(
    sink: default_sink_for_environment,
    datagram_builder_class: default_datagram_builder_class_for_implementation,
    default_sample_rate: statsd_sample_rate,
    prefix: statsd_prefix,
    default_tags: statsd_default_tags,
  )
end

#default_datagram_builder_class_for_implementation ⇒ Object 



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# File 'lib/statsd/instrument/environment.rb', line 116

def default_datagram_builder_class_for_implementation
  case statsd_implementation
  when 'statsd'
    StatsD::Instrument::StatsDDatagramBuilder
  when 'datadog', 'dogstatsd'
    StatsD::Instrument::DogStatsDDatagramBuilder
  else
    raise NotImplementedError, "No implementation for #{statsd_implementation}"
  end
end

#default_sink_for_environment ⇒ Object 



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# File 'lib/statsd/instrument/environment.rb', line 127

def default_sink_for_environment
  case environment
  when 'production', 'staging'
    StatsD::Instrument::UDPSink.for_addr(statsd_addr)
  when 'test'
    StatsD::Instrument::NullSink.new
  else
    StatsD::Instrument::LogSink.new(StatsD.logger)
  end
end

#environment ⇒ String

Detects the current environment, either by asking Rails, or by inspecting environment variables.

  • Within a Rails application, Rails.env is used.
  • It will check the following environment variables in order: RAILS_ENV, RACK_ENV, ENV.
  • If none of these are set, it will return development

Returns:

  • (String) —

    The detected environment.



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# File 'lib/statsd/instrument/environment.rb', line 68

def environment
  if env['STATSD_ENV']
    env['STATSD_ENV']
  elsif defined?(Rails) && Rails.respond_to?(:env)
    Rails.env.to_s
  else
    env['RAILS_ENV'] || env['RACK_ENV'] || env['ENV'] || 'development'
  end
end

#statsd_addr ⇒ Object 



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# File 'lib/statsd/instrument/environment.rb', line 90

def statsd_addr
  env.fetch('STATSD_ADDR', 'localhost:8125')
end

#statsd_default_tags ⇒ Object 



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# File 'lib/statsd/instrument/environment.rb', line 94

def statsd_default_tags
  env.key?('STATSD_DEFAULT_TAGS') ? env.fetch('STATSD_DEFAULT_TAGS').split(',') : nil
end

#statsd_implementation ⇒ Object 



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# File 'lib/statsd/instrument/environment.rb', line 78

def statsd_implementation
  env.fetch('STATSD_IMPLEMENTATION', 'datadog')
end

#statsd_prefix ⇒ Object 



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# File 'lib/statsd/instrument/environment.rb', line 86

def statsd_prefix
  env.fetch('STATSD_PREFIX', nil)
end

#statsd_sample_rate ⇒ Object 



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# File 'lib/statsd/instrument/environment.rb', line 82

def statsd_sample_rate
  env.fetch('STATSD_SAMPLE_RATE', 1.0).to_f
end