Change HTTPUnprocessableEntity to HTTPBadRequest

Change HTTPUnprocessableEntity to HTTPBadRequest, and use the
parameter 'explanation' in place of'detail' to show the correct
error message.
This patch fixes this bug.

Change-Id: I6dc2cbe29f24634138ba4c5255b0edd7b8ad6b0e
Closes-Bug: #1283876
_translate_from_glance() can cause an unnecessary HTTP request

After returning from a get() call to python-glanceclient, nova runs a
translation function on the returned Image to get the data it wants. Part of
this process is checking for an expected set of attributes, one of which is
the deletion time ('deleted_at'). However, if the image has not been deleted,
deleted_at key will not exist. This forces another call to glance to occur for
the same image. A similar problem exists for the checksum attribute, which does
not exist before an image is active. The fix here is to only consider
deleted_at and checksum if they are expected to be present.

Change-Id: I67b7dd16a94fe60d873c012f6bd246ab24500d5a
Closes-Bug: #1275173
Change NotFound to InstanceNotFound in server_diagnostics.py

According to the get() method in nova/compute/api.py,
the index() method in nova/api/openstack/compute/
contrib/server_diagnostics.py should catch the
InstanceNotFound, rather than the NotFound.
This patch just applies to V2 API, V3 API is already
catching InstanceNotFound.

Change-Id: I9e021837b9050dade9af4725a0712f260eac6f7a
Closes-bug: #1296662
Merge "Change HTTPUnprocessableEntity to HTTPBadRequest"
Merge "Change NotFound to InstanceNotFound in server_diagnostics.py"
Merge "_translate_from_glance() can cause an unnecessary HTTP request"
libvirt: pause mode is not supported by all drivers

Only KVM/Qemu drivers support the VIR_DOMAIN_START_PAUSED flag
Booting guests on other drivers with the above flag will make it fail.

Closes-Bug: 1301453
Change-Id: Ia98e018b686c4ec3c15fd1f6bcc78188f330fcef
Adding image multiple location support

Images now support multiple locations within its metadata and it may be
stored on more than one backend storage. Nova should add a layer to
transparently handle image preparing and removing for an instance by the
best approach/location, and it should allow administrators to configure
the image handler pipeline with the order who preferred to the layer.

Also, based on this structure we could implement particular sub-class in
relevant hypervisor layer with more advanced functions, such as CoW
making, snapshot capturing and etc. in future.

Implement bp: image-multiple-location
DocImpact

Change-Id: Idce8d21ae37bfdbb28a2567120a83d1061061904
Signed-off-by: Zhi Yan Liu <zhiyanl@cn.ibm.com>
Move libvirt RBD utilities to a new file

This will make it easier to share rbd-related code with
cinder and glance. Port the applicable unit tests over
from cinder.

Change-Id: I5bf08da87daf1d98f326f21cf33aba68aa830785
Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
enable cloning for rbd-backed ephemeral disks

Currently when using rbd as an image backend, nova downloads the
glance image to local disk and then copies it again into rbd. This
can be very slow for large images, and wastes bandwidth as well as
disk space.

When the glance image is stored in the same ceph cluster, the data is
being pulled out and pushed back in unnecessarily. Instead, create a
copy-on-write clone of the image. This is fast, and does not depend
on the size of the image. Instead of taking minutes, booting takes
seconds, and is not limited by the disk copy.

Add some rbd utility functions from cinder to support cloning and
let the rbd imagebackend rely on librbd instead of the rbd
command line tool for checking image existence.

Add an ImageHandler for rbd that does the cloning if an applicable
image location is available. If no such location is available, or rbd
is not configured for ephemeral disks, this handler does nothing, so
enable it by default.

blueprint rbd-clone-image-handler
Closes-bug: 1226351
Change-Id: I9b77a50206d0eda709df8356faaeeba35d232f22
Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
Signed-off-by: Zhi Yan Liu <zhiyanl@cn.ibm.com>
Use library instead of CLI to cleanup RBD volumes

'rbd list' CLI returns error code when there are no rbd volumes, which
causes problems during live migration of VMs with RBD backed ephemeral
volumes. It's safer to use the library that only raises an exception in
case of a real problem.

The only case where rbd CLI is still justified is import, which is
needed to correctly import sparse image files.

All code related to cleanup of RBD volumes is moved to rbd_utils.py,
this fixes a yo-yo problem with single-use methods scattered across 3
different files, and minimizes impact of this fix on imports in
imagebackend and utils.

Flake8 F401 in test_libvirt.py has to be ignored since flake8 doesn't
recognize use of an imported module in a @mock.patch decorator.

Change-Id: I92cd6b16fbd93b377fe47b15d22efbbf68d02513
Signed-off-by: Dmitry Borodaenko <dborodaenko@mirantis.com>