Class: Dumper::Agent

Inherits:
Object
  • Object
show all
Includes:
Utility::LoggingMethods
Defined in:
lib/dumper/agent.rb

Constant Summary collapse

API_VERSION = 
1

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Utility::LoggingMethods

#log, #log_last_error, #logger, #stdout_logger

Constructor Details

#initialize(options = {}) ⇒ Agent

Returns a new instance of Agent.



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# File 'lib/dumper/agent.rb', line 22

def initialize(options = {})
  log 'app_key is missing' if options[:app_key].blank?

  @stack = Dumper::Stack.new
  @api_base = options[:api_base] || 'http://dumper.io'
  @app_key = options[:app_key]
  @app_env = @stack.rails_env
  @app_name = ObjectSpace.each_object(Rails::Application).first.class.name.split("::").first
  logger.level = stdout_logger.level = options[:loglevel] if options[:loglevel]
end

Instance Attribute Details

#stack ⇒ Object (readonly)

Returns the value of attribute stack.



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# File 'lib/dumper/agent.rb', line 10

def stack
  @stack
end

Class Method Details

.start(options = {}) ⇒ Object 



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# File 'lib/dumper/agent.rb', line 13

def start(options = {})
  new(options).start
end

.start_if(options = {}) ⇒ Object 



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# File 'lib/dumper/agent.rb', line 17

def start_if(options = {})
  start(options) if yield
end

Instance Method Details

#api_request(method_name, options) ⇒ Object 



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# File 'lib/dumper/agent.rb', line 92

def api_request(method_name, options)
  uri = URI.parse("#{@api_base}/api/#{method_name}")
  http = Net::HTTP.new(uri.host, uri.port)
  if uri.is_a? URI::HTTPS
    http.use_ssl = true
    http.verify_mode = OpenSSL::SSL::VERIFY_NONE
  end
  request = Net::HTTP::Post.new(uri.request_uri)
  request['x-app-key'] = @app_key
  request['x-app-env'] = @app_env
  request['x-api-version'] = API_VERSION.to_s
  request['user-agent'] = "Dumper-RailsAgent/#{Dumper::VERSION} (ruby #{::RUBY_VERSION} #{::RUBY_PLATFORM} / rails #{Rails::VERSION::STRING})"
  if options[:params]
    request.set_form_data(options[:params])
  else
    # Without empty string, WEBrick would complain WEBrick::HTTPStatus::LengthRequired for empty POSTs
    request.body = options[:json] || ''
    request['Content-Type'] = 'application/octet-stream'
  end

  response = http.request(request)
  if response.code == '200'
    log response.body, :debug
    MultiJson.load(response.body).with_indifferent_access
  else
    log "******** ERROR on api: #{method_name}, resp code: #{response.code} ********", :error
    {} # return empty hash
  end
rescue
  log_last_error
  {} # return empty hash
end

#register_hash ⇒ Object 



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# File 'lib/dumper/agent.rb', line 83

def register_hash
  {
    :hostname => Socket.gethostname,
    :agent_version => Dumper::VERSION,
    :app_name => @app_name,
    :stack => @stack.to_hash,
  }
end

#start ⇒ Object 



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# File 'lib/dumper/agent.rb', line 33

def start
  return unless @stack.supported?
  log "stack: dispatcher = #{@stack.dispatcher}, framework = #{@stack.framework}, rackup = #{@stack.rackup}"

  @loop_thread = Thread.new { start_loop }
  @loop_thread[:name] = 'Loop Thread'
end

#start_loop ⇒ Object 



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# File 'lib/dumper/agent.rb', line 41

def start_loop
  sec = 1
  begin
    sec *= 2
    log "sleeping #{sec} seconds for agent/register", :debug
    sleep sec
    json = api_request('agent/register', :json => MultiJson.dump(register_hash))
  end until json[:status]

  return log("agent stopped: #{json.to_s}") if json[:status] == 'error'

  @token = json[:token]
  log "agent started as #{@token ? 'primary' : 'secondary'}"
  sleep 1.hour + rand(10) unless @token

  loop do
    json = api_request('agent/poll', :params => { :token => @token })

    if json[:status] == 'ok'
      # Promoted or demoted?
      if json[:token]
        @token = json[:token] # promote
      else
        @token = nil # demote
      end

      if json[:job]
        if pid = fork
          # Parent
          srand # Ruby 1.8.7 needs reseeding - http://bugs.ruby-lang.org/issues/4338
          Process.detach(pid)
        else
          # Child
          Dumper::Job.new(self, json[:job]).run_and_exit
        end
      end
    end

    sleep [ json[:interval].to_i, 60 ].max
  end
end