Subexec::Notifications

Instrumentation for Subexec commands using ActiveSupport::Notifications.

Read the full document documentation for ActiveSupport::Notifications first. All Subexec events can be subscribed to using the subexec.run key.

ActiveSupport::Notifications.subscribe('subexec.run') do |*args|
  # Your code here
end

The payload for events return the Subexec instance via the :sub key as well as the hostname of the machine running the command via the :hostname key. For example:

• :sub - Subexec object
• :hostname - The hostname of the machine as reported by Socket.gethostname.

ActiveSupport::Notifications.subscribe('subexec.run') do |*args|
  Subscribers::SubexecLibrato.new(*args)
end

module Subscribers
  class SubexecLibrato < Base

    def initialize(*args)
      @event = ActiveSupport::Notifications::Event.new(*args)
      process
    end

    def process
      sub = @event.payload[:sub]
      duration = @event.duration
      command = sub.command.split.first
      source = @event.payload[:hostname]
      Librato::Metrics.submit 'subexec.run' => {type: command, value: duration, source: source}
    end

  end
end

• Instrumenting Your Code With ActiveSupport Notifications
• Digging Deep with ActiveSupport::Notifications

The subexec-notifications gem is tested against ActiveSupport v3.x to v4.x. We run our tests on Travis CI in both Ruby 1.9 and 2.0. Check the .travis.yml file for the latest build information.

If you detect a problem, open up a github issue or fork the repo and help out. After you fork or clone the repository, the following commands will get you up and running on the test suite.

$ bundle install
$ bundle exec rake appraisal:setup
$ bundle exec rake appraisal test

We use the appraisal gem from Thoughtbot to help us generate the individual gemfiles for each ActiveSupport version and to run the tests locally against each generated Gemfile. The rake appraisal test command actually runs our test suite against all ActiveSupport versions in our Appraisal file. If you want to run the tests for a specific ActiveSupport version, use rake -T for a list. For example, the following command will run the tests for ActiveSupport v3.2 only.

$ bundle exec rake appraisal:v32 test

Our current build status is: