libvirt error when adding the os_command_line on non ami images

[Vladan Popovic]

qemu fails when booting an instance with the os_command_line on non ami images

----------------------------------------------------------------------------

Traceback (most recent call last):
  File "/usr/lib/python2.6/site-packages/nova/compute/manager.py", line 1066, in _build_instance
    set_access_ip=set_access_ip)
  File "/usr/lib/python2.6/site-packages/nova/compute/manager.py", line 360, in decorated_function
    return function(self, context, *args, **kwargs)
  File "/usr/lib/python2.6/site-packages/nova/compute/manager.py", line 1476, in _spawn
    LOG.exception(_('Instance failed to spawn'), instance=instance)
  File "/usr/lib/python2.6/site-packages/nova/openstack/common/excutils.py", line 68, in __exit__
    six.reraise(self.type_, self.value, self.tb)
  File "/usr/lib/python2.6/site-packages/nova/compute/manager.py", line 1473, in _spawn
    block_device_info)
  File "/usr/lib/python2.6/site-packages/nova/virt/libvirt/driver.py", line 2237, in spawn
    block_device_info)
  File "/usr/lib/python2.6/site-packages/nova/virt/libvirt/driver.py", line 3572, in _create_domain_and_network
    domain = self._create_domain(xml, instance=instance, power_on=power_on)
  File "/usr/lib/python2.6/site-packages/nova/virt/libvirt/driver.py", line 3513, in _create_domain
    domain.XMLDesc(0))
  File "/usr/lib/python2.6/site-packages/nova/openstack/common/excutils.py", line 68, in __exit__
    six.reraise(self.type_, self.value, self.tb)
  File "/usr/lib/python2.6/site-packages/nova/virt/libvirt/driver.py", line 3508, in _create_domain
    domain.createWithFlags(launch_flags)
  File "/usr/lib/python2.6/site-packages/eventlet/tpool.py", line 187, in doit
    result = proxy_call(self._autowrap, f, *args, **kwargs)
  File "/usr/lib/python2.6/site-packages/eventlet/tpool.py", line 147, in proxy_call
    rv = execute(f,*args,**kwargs)
  File "/usr/lib/python2.6/site-packages/eventlet/tpool.py", line 76, in tworker
    rv = meth(*args,**kwargs)
  File "/usr/lib64/python2.6/site-packages/libvirt.py", line 708, in createWithFlags
    if ret == -1: raise libvirtError ('virDomainCreateWithFlags() failed', dom=self)
libvirtError: internal error Process exited while reading console log output: char device redirected to /dev/pts/5
-append only allowed with -kernel option

----------------------------------------------------------------------------

Is this the correct behaviour or should the instance be booted with a log warning that the os_command_line isn't considered since it only applies to ami images in qemu?

The easiest and least painful solution I could think of is to move the code in the kernel_id check, but I don't know how that would affect other hypervisors. Any comments by people with greater experience with the other hypervisors are more than welcome.

[Stephen Gordon (sgordon)]

It's worth noting that neither the original blueprint [1] or the commit message for the patch [2] that added this functionality mention any restrictions around image type, though the behaviour is understandable it should have been noted for documentation etc.

[1] https://blueprints.launchpad.net/nova/+spec/enable-libvirt-driver-to-read-kernel-command-line-from-glance-image
[2] https://review.openstack.org/#/c/65028/

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/87329

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/87329
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=c6a6003a99c27c920ead194d5df6051800e8a9b4
Submitter: Jenkins
Branch: master

commit c6a6003a99c27c920ead194d5df6051800e8a9b4
Author: Vladan Popovic <email address hidden>
Date: Mon Apr 14 13:04:13 2014 -0400

    libvirt: Use os_command_line when kernel_id is set

    Patch Iad53c687053bdb5469baad4331ea55f428c170b0 breaks libvirt with
    "-append only allowed with -kernel option" when using images without an
    explicit boot kernel set because the -kernel option (kernel_id in nova)
    isn't supplied for those image types.

    This patch reads the os_command_line property from the image metadata
    only when using images with an explicit boot kernel set and ignores it
    otherwise.

    Closes-bug: 1300861

    Change-Id: I06c2d9930e0f36a0d7057b6a0f5c9c591caac43f