null_statsd

NullStatsd

NullStatsd is a Null Object Pattern implementation of a Statsd client, allowing for conveniently stubbed Statsd objects in your development and testing environments.

Installation

Add this line to your application's Gemfile:

gem 'null_statsd'

And then execute:

$ bundle

Or install it yourself as:

$ gem install null_statsd

Usage

Create a wrapper around your Statsd implementation:

module MyStatsd
  def self.new
    if ENV["STATSD_HOST"] && ENV["STATSD_PORT"]
      Statsd.new(ENV["STATSD_HOST"], ENV["STATSD_PORT"])
    else
      NullStatsd::Statsd.new(host: "fake.host", port: 1234, logger: Logger.new($stderr))
    end
  end
end

# or perhaps

if Rails.env.production? || Rails.env.staging?
  $statsd = Datadog::Statsd.new(ENV["DD_HOST"], ENV["DD_PORT"])
else
  $statsd = NullStatsd::Statsd.new(host: "fa.ke", port: 42, logger: Rails.logger)
end

Create an instance and use it as normal:

MyStatsd.new.increment(...)
$statsd.increment(...)

Notice that your statsd endpoint is not receiving data, but your logs are.

[NullStatsD host:42] Incrementing media.book.consumed with opts {"genre":"science_fiction"}
[NullStatsD host:42] Decrementing media.book.on_hand
[NullStatsD host:42] Recording timing info in book.checkout -> 0.512917 sec

Supported Calls

statsd = NullStatsd::Statsd.new(host: "a.co" port: 42, logger: Logger.new($stdout))
# => [NullStatsD a.co:42] Connecting to fake Statsd, pretending to be on fake.com:4242

statsd.increment "media.book.consumed", genre: "horror"
# => [NullStatsD a.co:42] Incrementing media.book.consumed with opts {"genre":"horror"}

statsd.decrement "media.book.on_hand", genre: "science fiction"
# => [NullStatsD a.co:42] Decrementing media.book.on_hand with opts {"genre":"science fiction"}

statsd.count "responses", 3
# => [NullStatsD a.co:42] Increasing responses by 3

statsd.gauge "media.book.return_time", 12, measurement: "days"
# => [NullStatsD a.co:42] Setting gauge media.book.return_time to 12 with opts {"measurement":"days"}

statsd.histogram "media.book.lent.hour", 42
# => [NullStatsD a.co:42] Logging histogram media.book.lent.hour -> 42

statsd.timing "book checkout", 94, tags: "speedy"
# => [NullStatsD a.co:42] Timing book checkout at 94 ms with opts {"tags":"speedy"}

statsd.set "media.book.lent", 10_000_000
# => [NullStatsD a.co:42] Setting media.book.lent to 10000000

statsd.service_check "door.locked", "ok"
# => [NullStatsD a.co:42] Service check door.locked: ok

statsd.event "Leak", "The library roof has a leak on the west end. Please take care"
# => [NullStatsD a.co:42] Event Leak: The library roof has a leak on the west end. Please take care

statsd.time("media.movie.consume") do
  Movie.new().watch
end
# => [NullStatsD a.co:42] Recording timing info in media.movie.consumed -> 12323.23 sec

statsd.close
# => [NullStatsD a.co:42] Close called

statsd.batch do |s|
  s.increment "foo.bar"
  s.increment "baz"
end
# This just executes the block, yielding the statsd instance to it.

Testing

rake spec

License

This gem is available as open source under the terms of the MIT License.

Contributing

Bug reports and pull requests are welcome on GitHub.