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[Feodor Tersin <ftersin@xxxxxxxxxxxxxxxx>]

Public bug reported:

For EBS images AWS returns device names, volume sizes, delete on
termination flags in block device mapping structure.

$ euca-describe-images ami-d13845e1
IMAGE	ami-d13845e1	amazon/amzn-ami-hvm-2014.03.2.x86_64-ebs	amazon	available	public	x86_64	machine				ebs	hvm	xen
BLOCKDEVICEMAPPING	/dev/xvda	snap-d15cde24	8	true

The same in xml form:
            <blockDeviceMapping>
                <item>
                    <deviceName>/dev/xvda</deviceName>
                    <ebs>
                        <snapshotId>snap-d15cde24</snapshotId>
                        <volumeSize>8</volumeSize>
                        <deleteOnTermination>true</deleteOnTermination>
                        <volumeType>standard</volumeType>
                    </ebs>
                </item>
            </blockDeviceMapping>

But Nova didn't do it now:

$ euca-describe-images ami-0000000a
IMAGE	ami-0000000a	None (sn-in)	ef3ddd7aa4b24cda974200baef02730b	available	private		machine	aki-00000002	ari-00000003		instance-store		
BLOCKDEVICEMAPPING		snap-00000005

The same in xml form:
      <blockDeviceMapping>
        <item>
          <ebs>
            <snapshotId>snap-00000005</snapshotId>
          </ebs>
        </item>
      </blockDeviceMapping>

NB. In Grizzly device names and delete on termination flags was returned. It was changed by https://github.com/openstack/nova/commit/33e3d4c6b9e0b11500fe47d861110be1c1981572
Now these attributes are not stored in instance snapshots, so there is no way to output them.

Device name is most critical attribute. Because there is another one compatibility issue: Nova isn't able to adjust attributes of volume being created at instance launch stage. For example in AWS we can change volume size and delete on termination flag of a device by set new values in parameters of run instance command. To identify the device in image block device mapping we use device name. For example:
euca-run-instances ... -b /dev/vda=:100
runs an instance with vda device increased to 100 GB.
Thus if we haven't device names in images, we haven't a chance to fix this compatibility problem.

** Affects: nova
     Importance: Undecided
         Status: New

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https://bugs.launchpad.net/bugs/1370177

Title:
  Lack of EC2 image attributes for volume backed snapshot.

Status in OpenStack Compute (Nova):
  New

Bug description:
  For EBS images AWS returns device names, volume sizes, delete on
  termination flags in block device mapping structure.

  $ euca-describe-images ami-d13845e1
  IMAGE	ami-d13845e1	amazon/amzn-ami-hvm-2014.03.2.x86_64-ebs	amazon	available	public	x86_64	machine				ebs	hvm	xen
  BLOCKDEVICEMAPPING	/dev/xvda	snap-d15cde24	8	true

  The same in xml form:
              <blockDeviceMapping>
                  <item>
                      <deviceName>/dev/xvda</deviceName>
                      <ebs>
                          <snapshotId>snap-d15cde24</snapshotId>
                          <volumeSize>8</volumeSize>
                          <deleteOnTermination>true</deleteOnTermination>
                          <volumeType>standard</volumeType>
                      </ebs>
                  </item>
              </blockDeviceMapping>

  But Nova didn't do it now:

  $ euca-describe-images ami-0000000a
  IMAGE	ami-0000000a	None (sn-in)	ef3ddd7aa4b24cda974200baef02730b	available	private		machine	aki-00000002	ari-00000003		instance-store		
  BLOCKDEVICEMAPPING		snap-00000005

  The same in xml form:
        <blockDeviceMapping>
          <item>
            <ebs>
              <snapshotId>snap-00000005</snapshotId>
            </ebs>
          </item>
        </blockDeviceMapping>

  NB. In Grizzly device names and delete on termination flags was returned. It was changed by https://github.com/openstack/nova/commit/33e3d4c6b9e0b11500fe47d861110be1c1981572
  Now these attributes are not stored in instance snapshots, so there is no way to output them.

  Device name is most critical attribute. Because there is another one compatibility issue: Nova isn't able to adjust attributes of volume being created at instance launch stage. For example in AWS we can change volume size and delete on termination flag of a device by set new values in parameters of run instance command. To identify the device in image block device mapping we use device name. For example:
  euca-run-instances ... -b /dev/vda=:100
  runs an instance with vda device increased to 100 GB.
  Thus if we haven't device names in images, we haven't a chance to fix this compatibility problem.

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