def _command_return(self, uuid, returncode, message=None):
self.log.debug('returning code %s (uuid=%s)', str(returncode), uuid)
response = json.dumps(dict(returncode=returncode, message=message))
self.xen_store.write(XenStore.join(XenStore.GUEST_DATA, uuid),
response)
self.log.debug('removing command from queue (uuid=%s)', uuid)
self.xen_store.remove(XenStore.join(XenStore.HOST_DATA, uuid))
def __iter__(self):
try:
uuid_list = self.xen_store.dir(XenStore.HOST_DATA)
except XenStoreError as error:
if error.returncode == 1:
return
else:
raise
self.log.debug('got %d commands pending', len(uuid_list))
for uuid in uuid_list:
if uuid in self.pending:
self.log.debug('ignoring (uuid=%s), pending already', uuid)
continue
self.log.debug('reading (uuid=%s)', uuid)
try:
data = self.xen_store.read(
XenStore.join(XenStore.HOST_DATA, uuid))
except XenStoreError as error:
self.log.error('error reading (uuid=%s): %s', UUID, str(error))
continue
self.log.debug(repr(data))
try:
data = json.loads(''.join(s.rstrip()
for s in data.splitlines()))
except Exception as error:
self.log.error('error decoding (uuid=%s): %s',
uuid,
str(error),
exc_info=True)
continue
try:
class_name = data.pop('name')
except KeyError:
self.log.error('invalid object, name missing (uuid=%s)', uuid)
continue
try:
value = data.pop('value')
except KeyError:
self.log.error('invalid object, value missing (uuid=%s)', uuid)
continue
try:
command_class = Command._subclasses[class_name]
except KeyError:
self.log.warning('unsupported: %s (uuid=%s)', class_name, uuid)
self._command_return(
uuid, Command.RET_UNSUPPORTED,
'unsupported command: {0}'.format(class_name))
continue
try:
command = command_class(self, uuid, value)
except Exception as error:
self.log.exception()
continue
self.pending[command.uuid] = command
yield command
