Add new ec2 volume db API calls

The existing API calls for the EC2 volume ID mappings only returned
the EC2 ID or the UUID, not the full mapping.  We really want APIs
that return the whole mapping for use with a nova object.  This patch
adds those APIs which will be used by the VolumeMapping nova object.

Change-Id: I86361a557254dbddeae2ea49e986add813e5a934
libvirt: Make `fakelibvirt.libvirtError` match

When test code uses `libvirtError`, it may refer to
`libvirt.libvirtError` or `fakelibvirt.libvirtError` depending on
whether `libvirt-python` is installed.

The existing code had incompatible `__init__` singatures between the
two, meaning that a test could pass locally but fail when run on
Jenkins.

The solution is to make `fakelibvirt.libvirtError` match libvirt 1.2.3
exactly.

A convenience function, `make_libvirtError`, is introduced so that
exceptions can still be created in one shot.

Change-Id: I5aaecc57504c4aea3c049610ef188978c25cfdc4
Closes-Bug: 1305186
Don't translate debug level logs in nova.volume

Our translation policy
(https://wiki.openstack.org/wiki/LoggingStandards#Log_Translation) calls
for not translating debug level logs. This is to help prioritize log
translation. Furthermore translation has a performance overhead, even if
the log isn't used (since nova doesn't support lazy translation yet).

Change-Id: Ib529afea4d1696d8905e2d533803562130950d83
Don't translate debug level logs in nova.api

Our translation policy
(https://wiki.openstack.org/wiki/LoggingStandards#Log_Translation) calls
for not translating debug level logs. This is to help prioritize log
translation. Furthermore translation has a performance overhead, even if
the log isn't used (since nova doesn't support lazy translation yet).

Change-Id: Ifb04bf41a47f485e8c668632d3a6ac51e02a16f8
Don't translate debug level logs in nova.cells

Our translation policy
(https://wiki.openstack.org/wiki/LoggingStandards#Log_Translation) calls
for not translating debug level logs. This is to help prioritize log
translation. Furthermore translation has a performance overhead, even if
the log isn't used (since nova doesn't support lazy translation yet).

Change-Id: Idb346d04f24cbbc19b6e41af6e4782ac1c49d3b8
Don't translate debug level logs in nova.conductor

Our translation policy
(https://wiki.openstack.org/wiki/LoggingStandards#Log_Translation) calls
for not translating debug level logs. This is to help prioritize log
translation. Furthermore translation has a performance overhead, even if
the log isn't used (since nova doesn't support lazy translation yet).

Change-Id: Id270b6c7e020679c3e2e3931300e82ea3489e942
Merge "Don't translate debug level logs in nova.volume"
Merge "Don't translate debug level logs in nova.api"
Merge "Don't translate debug level logs in nova.cells"
Merge "Don't translate debug level logs in nova.conductor"
Merge "Add new ec2 volume db API calls"
Merge "libvirt: Make `fakelibvirt.libvirtError` match"
Revert "Address the comments of the merged image handler patch"

This reverts commit 9e8513e6fe4bf8a8759ad0c1d71594f952d920ad.

Change-Id: I3cf8000a3e984c57441a226d3139acbf3e346825
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>
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>
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 a direct_fetch() method to the image backend, so backends like rbd
can make optimizations like this. Try to use direct_fetch() for the root
disk when it comes from an image, but fall back to fetch_to_raw() if
direct_fetch() fails.

Implements: blueprint rbd-clone-image-handler
Closes-Bug: 1226351
Change-Id: I9b77a50206d0eda709df8356faaeeba35d232f22
Co-Authored-By: Dmitry Borodaenko <dborodaenko@mirantis.com>
Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
Signed-off-by: Zhi Yan Liu <zhiyanl@cn.ibm.com>
Signed-off-by: Dmitry Borodaenko <dborodaenko@mirantis.com>