exceptions get eaten during image register failures

[Vish Ishaya]

When image register fails, the underlying exception gets eaten because out of scope variables are being referenced in the error log.

2011-08-15 14:36:10,385 DEBUG nova.utils [-] Running cmd (subprocess): openssl enc -d -aes-128-cbc -in /tmp/tmpIHkMkG/image.encrypted -K 57fbea5c3e106e0e6aec2d89ef5171ea -iv 77f27e730c319a341782b091b97216a5 -out /tmp/tmpIHkMkG/image.tar.gz from (pid=16720) execute /home/ctoteam/nova/nova/utils.py:143Traceback (most recent call last): File "/usr/lib/python2.6/logging/__init__.py", line 776, in emit msg = self.format(record) File "/usr/lib/python2.6/logging/__init__.py", line 654, in format
    return fmt.format(record) File "/home/ctoteam/nova/nova/log.py", line 214, in format
    return logging.Formatter.format(self, record)
  File "/usr/lib/python2.6/logging/__init__.py", line 436, in format
    record.message = record.getMessage()
  File "/usr/lib/python2.6/logging/__init__.py", line 306, in getMessage
    msg = msg % self.args
KeyError: u'image_location'
Traceback (most recent call last):
  File "/usr/lib/python2.6/dist-packages/eventlet/hubs/poll.py", line 97, in wait
    readers.get(fileno, noop).cb(fileno)
  File "/home/ctoteam/nova/nova/image/s3.py", line 267, in delayed_create
    raise
TypeError: exceptions must be old-style classes or derived from BaseException, not NoneType
Removing descriptor: 6

[Vish Ishaya (vishvananda)]

Furthermore, it appears that now that we have an eventlet friendly-db library, we can't do db updates in exception handlers and reraise:

2011-08-15 16:43:30,086 ERROR nova.image.s3 [-] Failed to upload ttbb2/ttylinux-uec-i386-11.2_2.6.35-16_1.img.manifest.xml to /tmp/tmp7jXqlf
Traceback (most recent call last):
  File "/usr/lib/python2.6/dist-packages/eventlet/hubs/poll.py", line 97, in wait
    readers.get(fileno, noop).cb(fileno)
  File "/home/ctoteam/nova/nova/image/s3.py", line 271, in delayed_create
    raise
TypeError: exceptions must be old-style classes or derived from BaseException, not NoneType