instance path wrongfully trimmed during cold migration

[Claudiu Belu]

During cold migration, the following happens:

1. source node stops the VMs, moves its file to a _revert path (\some\path\to\instance_000000be_revert), destroys the VM, and returns the _revert path as disk_info.
2. the destination node gets the disk_info. If it was configured not to move the VM storage (multiple CSVs cluster scenario), it will copy the files from the _revert path to a path without the ending _revert (\some\path\to\instance_000000be).

The issue is that string.rstrip function behaves in an unexpected way:

>>> "instance-000000be_revert".rstrip('_revert')
'instance-000000b'

This can lead to various errors.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/503562
Committed: https://git.openstack.org/cgit/openstack/compute-hyperv/commit/?id=e00240f5d7e2d8e385b8c0d6ea18ed9eddd6e5d1
Submitter: Jenkins
Branch: master

commit e00240f5d7e2d8e385b8c0d6ea18ed9eddd6e5d1
Author: Claudiu Belu <email address hidden>
Date: Wed Sep 13 11:31:12 2017 +0300

    Fixes cold migration path trimming issue

    During cold migration, the following steps happen:

    1. The source node will stop the VM, copy the VM files to a _revert path,
    destroy the VM, and return the _revert path as disk_info.
    2. The destination node will get that disk_info, and if it was configured
    not to move the storage (multiple CSVs cluster scenario), it will just
    copy the files to a path without the ending _revert.

    The issue is that rstrip can strip more characters than desired. It will
    remove all characters contained by "_revert" from the given path's ending.
    For example:

    "instance_000000be_revert".rstrip("_revert") => "instance_000000b"

    Change-Id: I784835800a961be4ba755a4d51edbc931eccdc57
    Closes-Bug: #1716862

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/pike
Review: https://review.openstack.org/504362

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/504362
Committed: https://git.openstack.org/cgit/openstack/compute-hyperv/commit/?id=4672aa051da6be9f4ff57457b59ff75ce344ce17
Submitter: Jenkins
Branch: stable/pike

commit 4672aa051da6be9f4ff57457b59ff75ce344ce17
Author: Claudiu Belu <email address hidden>
Date: Wed Sep 13 11:31:12 2017 +0300

    Fixes cold migration path trimming issue

    During cold migration, the following steps happen:

    1. The source node will stop the VM, copy the VM files to a _revert path,
    destroy the VM, and return the _revert path as disk_info.
    2. The destination node will get that disk_info, and if it was configured
    not to move the storage (multiple CSVs cluster scenario), it will just
    copy the files to a path without the ending _revert.

    The issue is that rstrip can strip more characters than desired. It will
    remove all characters contained by "_revert" from the given path's ending.
    For example:

    "instance_000000be_revert".rstrip("_revert") => "instance_000000b"

    Change-Id: I784835800a961be4ba755a4d51edbc931eccdc57
    Closes-Bug: #1716862
    (cherry picked from commit e00240f5d7e2d8e385b8c0d6ea18ed9eddd6e5d1)