Xenapi disk resize broken by use of privsep code

[Bob Ball]

Patch I6c695c04ae586fec6adc354257638116277dda88 (https://review.openstack.org/#/c/552242/) moved disk resizing into privsep. Unforutunately "None" was passed as the expected return code, which is not understood by processutils.
Further, Tempest flavor resizing moves from m1.nano to m1.micro, both of which have root_gb=0 thus skipping the resize code - so Tempest didn't spot this error.

May 14 11:26:45 DevStackOSDomU nova-compute[15359]: Traceback (most recent call last):
May 14 11:26:45 DevStackOSDomU nova-compute[15359]: File "/usr/local/lib/python2.7/dist-packages/oslo_privsep/daemon.py", line 445, in loop
May 14 11:26:45 DevStackOSDomU nova-compute[15359]: reply = self._process_cmd(*msg)
May 14 11:26:45 DevStackOSDomU nova-compute[15359]: File "/usr/local/lib/python2.7/dist-packages/oslo_privsep/daemon.py", line 428, in _process_cmd
May 14 11:26:45 DevStackOSDomU nova-compute[15359]: ret = func(*f_args, **f_kwargs)
May 14 11:26:45 DevStackOSDomU nova-compute[15359]: File "/usr/local/lib/python2.7/dist-packages/oslo_privsep/priv_context.py", line 209, in _wrap
May 14 11:26:45 DevStackOSDomU nova-compute[15359]: return func(*args, **kwargs)
May 14 11:26:45 DevStackOSDomU nova-compute[15359]: File "/opt/stack/nova/nova/privsep/fs.py", line 152, in resize2fs
May 14 11:26:45 DevStackOSDomU nova-compute[15359]: unprivileged_resize2fs(image, check_exit_code=check_exit_code, size=size)
May 14 11:26:45 DevStackOSDomU nova-compute[15359]: File "/opt/stack/nova/nova/privsep/fs.py", line 162, in unprivileged_resize2fs
May 14 11:26:45 DevStackOSDomU nova-compute[15359]: processutils.execute(*cmd, check_exit_code=check_exit_code)
May 14 11:26:45 DevStackOSDomU nova-compute[15359]: File "/usr/local/lib/python2.7/dist-packages/oslo_concurrency/processutils.py", line 414, in execute
May 14 11:26:45 DevStackOSDomU nova-compute[15359]: if not ignore_exit_code and _returncode not in check_exit_code:
May 14 11:26:45 DevStackOSDomU nova-compute[15359]: TypeError: argument of type 'NoneType' is not iterable
May 14 11:26:45 DevStackOSDomU nova-compute[15359]: DEBUG oslo.privsep.daemon [None req-aad511d7-9f4a-450c-bf86-c4e948d7409b service nova] privsep: reply[140577558810448]: (5, 'exceptions.TypeError', ("argum
ent of type 'NoneType' is not iterable",)) {{(pid=16155) loop /usr/local/lib/python2.7/dist-packages/oslo_privsep/daemon.py:456}}

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/568318

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/568318
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=eec0fe59ff08285181ac6c74ffcc36348b692b69
Submitter: Zuul
Branch: master

commit eec0fe59ff08285181ac6c74ffcc36348b692b69
Author: Bob Ball <email address hidden>
Date: Mon May 14 16:27:56 2018 +0100

    XenAPI: Pass expected return codes to resize2fs

    None is not tolerated by ProcessUtils, therefore make sure that [0] is passed as the
    expected return code

    Change-Id: I7d6335633479dfd7715444ef4aefc85ed41b8fa3
    Closes-Bug: #1771137

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/nova 18.0.0.0b2 development milestone.