If the region controller can't reach its upstream boot resource URL to check for images to sync, an unhandled exception is raised and a big log stack trace gets dumped to maas-django.log. Instead, we should alert the admin that the boot resources URL can't be reached.
Here's the stack trace:
ERROR 2014-10-22 10:41:04,913 twisted Unhandled Error
Traceback (most recent call last):
File "/usr/lib/python2.7/threading.py", line 783, in __bootstrap
self.__bootstrap_inner()
File "/usr/lib/python2.7/threading.py", line 810, in __bootstrap_inner
self.run()
File "/usr/lib/python2.7/threading.py", line 763, in run
self.__target(*self.__args, **self.__kwargs)
--- <exception caught here> ---
File "/usr/lib/python2.7/dist-packages/twisted/python/threadpool.py", line 191, in _worker
result = context.call(ctx, function, *args, **kwargs)
File "/usr/lib/python2.7/dist-packages/twisted/python/context.py", line 118, in callWithContext
return self.currentContext().callWithContext(ctx, func, *args, **kw)
File "/usr/lib/python2.7/dist-packages/twisted/python/context.py", line 81, in callWithContext
return func(*args,**kw)
File "/usr/lib/python2.7/dist-packages/maasserver/utils/async.py", line 153, in call_within_transaction
return func(*args, **kwargs)
File "/usr/lib/python2.7/dist-packages/maasserver/bootsources.py", line 117, in _cache_boot_sources
image_descriptions = download_all_image_descriptions(sources)
File "/usr/lib/python2.7/dist-packages/provisioningserver/import_images/download_descriptions.py", line 187, in download_all_image_descriptions
source['url'], keyring=source.get('keyring', None))
File "/usr/lib/python2.7/dist-packages/provisioningserver/import_images/download_descriptions.py", line 178, in download_image_descriptions
dumper.sync(reader, rpath)
File "/usr/lib/python2.7/dist-packages/simplestreams/mirrors/__init__.py", line 82, in sync
content, payload = reader.read_json(path)
File "/usr/lib/python2.7/dist-packages/simplestreams/mirrors/__init__.py", line 39, in read_json
raw = self.source(path).read().decode('utf-8')
File "/usr/lib/python2.7/dist-packages/simplestreams/contentsource.py", line 143, in read
self.open()
File "/usr/lib/python2.7/dist-packages/simplestreams/contentsource.py", line 139, in open
self.fd = self._open()
File "/usr/lib/python2.7/dist-packages/simplestreams/contentsource.py", line 127, in _open
return opener(*oargs, offset=self.offset)
File "/usr/lib/python2.7/dist-packages/simplestreams/contentsource.py", line 302, in __init__
self.req = requests.get(url, stream=True, auth=auth, headers=headers)
File "/usr/lib/python2.7/dist-packages/requests/api.py", line 55, in get
return request('get', url, **kwargs)
File "/usr/lib/python2.7/dist-packages/requests/api.py", line 44, in request
return session.request(method=method, url=url, **kwargs)
File "/usr/lib/python2.7/dist-packages/requests/sessions.py", line 455, in request
resp = self.send(prep, **send_kwargs)
File "/usr/lib/python2.7/dist-packages/requests/sessions.py", line 558, in send
r = adapter.send(request, **kwargs)
File "/usr/lib/python2.7/dist-packages/requests/adapters.py", line 378, in send
raise ConnectionError(e)
requests.exceptions.ConnectionError: HTTPConnectionPool(host='192.168.201.2', port=80): Max retries exceeded with url: /MAAS/images-stream/streams/v1/index.json (Caused by <class 'socket.error'>: [Errno 110] Connection timed out)
Crash - so critical. Looks like a potential release blocker to me as well as this is an easy mistake to make.