jobs: move ActiveJobLogSubscriber out of initializers

This is a class of its own, it doesn't need to be in the initializers.

app/lib/active_job/application_log_subscriber.rb

@@ -0,0 +1,80 @@
+require 'active_job/logging'
+require 'logstash-event'
+
+class ActiveJob::ApplicationLogSubscriber < ::ActiveJob::LogSubscriber
+  def enqueue(event)
+    process_event(event, 'enqueue')
+  end
+
+  def enqueue_at(event)
+    process_event(event, 'enqueue_at')
+  end
+
+  def perform(event)
+    process_event(event, 'perform')
+  end
+
+  def perform_start(event)
+    process_event(event, 'perform_start')
+  end
+
+  def log(data)
+    event = LogStash::Event.new(data)
+    event['message'] = "#{data[:job_class]}##{data[:job_id]} at #{data[:scheduled_at]}"
+    logger.send(Lograge.log_level, event.to_json)
+  end
+
+  def logger
+    Lograge.logger.presence || super
+  end
+
+  private
+
+  def process_event(event, type)
+    data = extract_metadata(event)
+    data.merge!(extract_exception(event))
+
+    case type
+    when 'enqueue_at'
+      data.merge!(extract_scheduled_at(event))
+    when 'perform'
+      data.merge!(extract_duration(event))
+    end
+
+    tags = ['job', type]
+    if data[:exception]
+      tags.push('exception')
+    end
+    data[:tags] = tags
+    data[:type] = 'tps'
+    data[:source] = ENV['SOURCE']
+
+    log(data)
+  end
+
+  def extract_metadata(event)
+    {
+      job_id: event.payload[:job].job_id,
+      queue_name: queue_name(event),
+      job_class: event.payload[:job].class.to_s,
+      job_args: args_info(event.payload[:job])
+    }
+  end
+
+  def extract_duration(event)
+    { duration: event.duration.to_f.round(2) }
+  end
+
+  def extract_exception(event)
+    event.payload.slice(:exception)
+  end
+
+  def extract_scheduled_at(event)
+    { scheduled_at: scheduled_at(event) }
+  end
+
+  # The default args_info makes a string. We need objects to turn into JSON.
+  def args_info(job)
+    job.arguments.map { |arg| arg.try(:to_global_id).try(:to_s) || arg }
+  end
+end