First few changes for the image diffs feature.

workers/image_diffs.py

@@ -0,0 +1,36 @@
+import logging
+import json
+
+from apscheduler.scheduler import Scheduler
+
+from data.queue import WorkQueue
+from endpoints.registry import process_image_changes
+
+
+logger = logging.getLogger(__name__)
+
+image_diff_queue = WorkQueue('imagediff')
+
+
+def process_work_items():
+  logger.debug('Getting work item from queue.')
+
+  item = imagediff.get()
+
+  if item:
+    logger.debug('Queue gave us some work: %s' % item.body)
+
+    request = json.loads(item.body)
+    process_image_changes(request['namepspace'], request['repository'],
+                          request['image_id'])
+  else:
+    logger.debug('No work today.')
+
+
+FORMAT = '%(asctime)-15s - %(levelname)s - %(pathname)s - %(funcName)s - %(message)s'
+logging.basicConfig(format=FORMAT, level=logging.DEBUG)
+
+sched = Scheduler()
+sched.start()
+
+sched.add_interval_job(process_work_items, seconds=10)