[2.0rc1] Unable to connect to BMC causes a traceback

[Andres Rodriguez]

It seems that we were unable to connect to the BMC for a valid reason, unfortunately, this is causing a traceback that should not be there.

==> /var/log/maas/rackd.log <== [12/2819]
2016-07-08 10:50:34 [ClusterClient,client] Failed to refresh power state.
        Traceback (most recent call last):
          File "/usr/lib/python3/dist-packages/twisted/internet/defer.py", line 434, in errback
            self._startRunCallbacks(fail)
          File "/usr/lib/python3/dist-packages/twisted/internet/defer.py", line 501, in _startRunCallbacks
            self._runCallbacks()
          File "/usr/lib/python3/dist-packages/twisted/internet/defer.py", line 588, in _runCallbacks
            current.result = callback(current.result, *args, **kw)
          File "/usr/lib/python3/dist-packages/twisted/internet/defer.py", line 1184, in gotResult
            _inlineCallbacks(r, g, deferred)
        --- <exception caught here> ---
          File "/usr/lib/python3/dist-packages/twisted/internet/defer.py", line 1126, in _inlineCallbacks
            result = result.throwExceptionIntoGenerator(g)
          File "/usr/lib/python3/dist-packages/twisted/python/failure.py", line 389, in throwExceptionIntoGenerator
            return g.throw(self.type, self.value, self.tb)
          File "/usr/lib/python3/dist-packages/provisioningserver/power/query.py", line 97, in get_power_state
            raise exc_type(exc_value).with_traceback(exc_trace)
          File "/usr/lib/python3/dist-packages/provisioningserver/power/query.py", line 86, in get_power_state
            system_id, hostname, power_type, context)
          File "/usr/lib/python3/dist-packages/twisted/internet/defer.py", line 1128, in _inlineCallbacks
            result = g.send(result)
          File "/usr/lib/python3/dist-packages/provisioningserver/drivers/power/__init__.py", line 254, in query
            raise exc_info[0](exc_info[1]).with_traceback(exc_info[2])
          File "/usr/lib/python3/dist-packages/provisioningserver/drivers/power/__init__.py", line 244, in query
            self.power_query, system_id, context)
          File "/usr/lib/python3/dist-packages/twisted/python/threadpool.py", line 246, in inContext
            result = inContext.theWork()
          File "/usr/lib/python3/dist-packages/twisted/python/threadpool.py", line 262, in <lambda>
            inContext.theWork = lambda: context.call(ctx, func, *args, **kw)
          File "/usr/lib/python3/dist-packages/twisted/python/context.py", line 118, in callWithContext
            return self.currentContext().callWithContext(ctx, func, *args, **kw)
          File "/usr/lib/python3/dist-packages/twisted/python/context.py", line 81, in callWithContext
            return func(*args,**kw)
          File "/usr/lib/python3/dist-packages/provisioningserver/drivers/power/amt.py", line 430, in power_query
            amt_command = self._get_amt_command(ip_address, power_pass)
          File "/usr/lib/python3/dist-packages/provisioningserver/drivers/power/amt.py", line 352, in _get_amt_command
            'exception')(error_info.get('message'))
        provisioningserver.drivers.power.PowerConnError: Could not connect to BMC. Check BMC configuration and try again.

[Newell Jensen (newell-jensen)]

After discussing this with the MAAS team we have decided that we are going to add Debug logging for the rack controller in a future release which will take care of the issue of seeing this traceback in the logs. That is, it will only show when the rack is in Debug mode.