'DescribeInstances' in ec2 shows wrong image-message to instance booting from volumes

[wingwj]

'DescribeInstances' in ec2 shows the wrong image message('ami-00000002') to the instance booting from a volume:

n781dba539a84:~ # euca-describe-instances i-0000003a
RESERVATION r-mdcwadip c1c092e1c88f4027aeb203d50d63135b
INSTANCE i-0000003a ami-00000002 wjvm1 running None (c1c092e1c88f4027aeb203d50d63135b, n781dba57c996) 0 m1.small 2014-02-10T07:00:40.000Z nova 20.20.16.12 ebs
BLOCKDEVICE /dev/vda vol-0000000d false

More info can be found here: http://paste.openstack.org/show/64087/

--------------

The codes in ec2utils.py:

def glance_id_to_id(context, glance_id):
    """Convert a glance id to an internal (db) id."""
    if glance_id is None:
        return
    try:
        return db.s3_image_get_by_uuid(context, glance_id)['id']
    except exception.NotFound:
        return db.s3_image_create(context, glance_id)['id']

------

The image_ref (as glance_id in this function) of the instance booting from a volume, will be "", not None.
The protected codes above can't take efforts.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/72579

[Openstack Gerrit (openstack-gerrit)]

Reviewed: https://review.openstack.org/72579
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=f1b76971ba9f670b0ee916625318d65f18c3c4aa
Submitter: Jenkins
Branch: master

commit f1b76971ba9f670b0ee916625318d65f18c3c4aa
Author: wingwj <email address hidden>
Date: Tue Feb 11 15:53:44 2014 +0800

    DescribeInstances in ec2 shows wrong image-message

    If one instance boots from a volume,
    the value of 'image_id' by 'DescribeInstances' in ec2,
    will be a wrong number.

    The value of 'image_ref' for this type of instances, is '', not None.
    So the original protected codes can't take efforts.

    Change-Id: I8c5e1c626f2b7873e7720f3615db1ee1ec6c681a
    Closes-Bug: #1278696