Comment 9 for bug 1653261

Reviewed: https://review.openstack.org/415898
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=eda54b1ed73b0c102f4352e1522e34908dc7c17f
Submitter: Jenkins
Branch: master

commit eda54b1ed73b0c102f4352e1522e34908dc7c17f
Author: Matt Riedemann <email address hidden>
Date: Fri Dec 30 12:27:48 2016 -0500

    Handle unicode when dealing with duplicate flavors during online migrations

    In python 2.7 you can't cast unicode to str and you'll get a
    UnicodeEncodeError if you try. Since our exception messages are
    translated, they can contain unicode and if we hit a duplicate flavor
    exception while performing online flavor migrations it will break the
    migration and block any further migrations until resolved - which would
    require manual intervention.

    This patch fixes the bug so that we use six.text_type instead of str
    for logging the duplicate exception and adds a test to exhibit the bug
    and prove it's fixed.

    On a side note, it's curious that we don't delete the duplicate flavor
    from the main database during the online data migration, but it's also
    strange that you'd have duplicates in the API database because the
    Flavor.create() checks to see if all flavors have been migrated from
    the main DB to the API DB and if not you can't create new flavors in
    the API DB - so the only way to get the duplicates is either by inserting
    them into the API DB manually or perhaps some other kind of race issue.
    Anyway, that's not dealt with here.

    Change-Id: I3bdb1a8ca72c3e72ddc3bc5102cff8df18148617
    Partial-Bug: #1653261