can update image size to smaller number even though cannot create it like that in the first place

[Dafna Ron]

if you try to create an image from file using the --size and giving a smaller size the source image we would fail
but we can use glance image-update to change the file after we create it.
so wither we do not need the size check to begin with or both should fail.

create image from a file (since this is the only time we currently check the size)

glance image-create --name image_size_file --disk-format qcow2 --container-format bare --file /tmp/39f89a6a-7fbb-43c0-a5ea-19b271f51829

[root@opens-vdsb ~(keystone_admin)]# glance image-list
+--------------------------------------+------------------+-------------+------------------+------------+--------+
| ID | Name | Disk Format | Container Format | Size | Status |
+--------------------------------------+------------------+-------------+------------------+------------+--------+
| 23bf4915-9f83-4eb5-a7c2-702de4d825e7 | image_size_file | qcow2 | bare | 1440612352 | active |

[root@opens-XXXX ~(keystone_admin)]# glance image-update 23bf4915-9f83-4eb5-a7c2-702de4d825e7 --size 1
+------------------+--------------------------------------+
| Property | Value |
+------------------+--------------------------------------+
| checksum | 18b7d574b7a1f0093fefc5484d9fb68d |
| container_format | bare |
| created_at | 2013-09-04T15:47:55 |
| deleted | False |
| deleted_at | None |
| disk_format | qcow2 |
| id | 23bf4915-9f83-4eb5-a7c2-702de4d825e7 |
| is_public | False |
| min_disk | 0 |
| min_ram | 0 |
| name | image_size_file |
| owner | ad326a6c11a742c6bfdf4ad63be0c889 |
| protected | False |
| size | 1 |
| status | active |
| updated_at | 2013-09-04T15:49:26 |
+------------------+--------------------------------------+

[root@opens-vdsb ~(keystone_admin)]# glance image-list
+--------------------------------------+------------------+-------------+------------------+------------+--------+
| ID | Name | Disk Format | Container Format | Size | Status |
+--------------------------------------+------------------+-------------+------------------+------------+--------+
| 23bf4915-9f83-4eb5-a7c2-702de4d825e7 | image_size_file | qcow2 | bare | 1 | active |

[Feilong Wang (flwang)]

Admin is allowed to change the image size.