Comment 5 for bug 1621200

Reviewed: https://review.openstack.org/367025
Committed: https://git.openstack.org/cgit/openstack/keystone/commit/?id=32328de6e37e1f9f55d563f8a55087dc7d6f46e1
Submitter: Jenkins
Branch: master

commit 32328de6e37e1f9f55d563f8a55087dc7d6f46e1
Author: Ronald De Rose <email address hidden>
Date: Wed Sep 7 23:51:09 2016 +0000

    Fixes password created_at errors due to the server_default

    Migration 002 sets the password created_at column to a TIMESTAMP type
    with a server_default=sql.func.now(). There are a couple problems
    that have been uncovered with this change:
    * We cannot guarantee that func.now() will generate a UTC timestamp.
    * For some older versions of MySQL, the default TIMESTAMP column will
    automatically be updated when other columns are updated:
    https://dev.mysql.com/doc/refman/5.5/en/timestamp-initialization.html

    This patch fixes the problem by recreating the password created_at
    column back to a DateTime type without a server_default:
    1) Drop and recreate the created_at column
    2) Update the created_at value
    3) Set the created_at column as not nullable

    Closes-Bug: #1621200
    Change-Id: Id5c607a777afb6565d66a336028eba796e3846b2