OpenStack Cinder "Copy Image to Volume"

Since OpenStack Havana release, Cinder has enforced a set of minimum features to avoid confusion of which driver features are supported by which OpenStack release. One of the required feature is "Copy Image to Volume". If your OpenStack instance is launched and booted from a volume, it'll be similar to AWS "Create Image (EBS AMI)" (ec2-create-image). This feature can be very useful when you like to modify the base image, create your customized image and upload it to Glance. Here's how you can achieve through OpenStack CLI:

1. Create a Cinder volume from a base image:

# glance image-list
# cinder create --image-id 2dfb6cd2-7a63-4c28-940e-b730969d3040 1

2. After modify the base image, create and upload the newly customized image to Glance:

# cinder list
+--------------------------------------+-----------+--------------+------+-------------+----------+-------------+
|                  ID                  |   Status  | Display Name | Size | Volume Type | Bootable | Attached to |
+--------------------------------------+-----------+--------------+------+-------------+----------+-------------+
| d7d2abfa-d882-45a3-ac80-ddb24631f666 | available |     None     |  1   |     None    |   true   |             |
+--------------------------------------+-----------+--------------+------+-------------+----------+-------------+

NOTE: By default the image disk format will be "raw". If your image disk format is not "raw", specify the --disk-format option.

# cinder upload-to-image d7d2abfa-d882-45a3-ac80-ddb24631f666 myCirrosImage --disk-format qcow2
+---------------------+--------------------------------------+
|       Property      |                Value                 |
+---------------------+--------------------------------------+
|   container_format  |                 bare                 |
|     disk_format     |                qcow2                 |
| display_description |                 None                 |
|          id         | d7d2abfa-d882-45a3-ac80-ddb24631f666 |
|       image_id      | 04ab89ab-e4e7-4389-bd46-e9e6aaf6de39 |
|      image_name     |            myCirrosImage             |
|         size        |                  1                   |
|        status       |              uploading               |
|      updated_at     |      2014-10-03T20:31:21.000000      |
|     volume_type     |                 None                 |
+---------------------+--------------------------------------+

3. It may take a while before the image is uploaded to Glance completely.

# glance image-list
+--------------------------------------+---------------+-------------+------------------+----------+--------+
| ID                                   | Name          | Disk Format | Container Format | Size     | Status |
+--------------------------------------+---------------+-------------+------------------+----------+--------+
| 2dfb6cd2-7a63-4c28-940e-b730969d3040 | cirros        | qcow2       | bare             | 13147648 | active |
| 04ab89ab-e4e7-4389-bd46-e9e6aaf6de39 | myCirrosImage | qcow2       | bare             |          | queued |
+--------------------------------------+---------------+-------------+------------------+----------+--------+

# glance image-list
+--------------------------------------+---------------+-------------+------------------+----------+--------+
| ID                                   | Name          | Disk Format | Container Format | Size     | Status |
+--------------------------------------+---------------+-------------+------------------+----------+--------+
| 2dfb6cd2-7a63-4c28-940e-b730969d3040 | cirros        | qcow2       | bare             | 13147648 | active |
| 04ab89ab-e4e7-4389-bd46-e9e6aaf6de39 | myCirrosImage | qcow2       | bare             | 38005440 | active |
+--------------------------------------+---------------+-------------+------------------+----------+--------+

NOTE: By default the uploaded image is private. If you are admin and would like to make the customized image public, use glance image-update:

# glance image-show 04ab89ab-e4e7-4389-bd46-e9e6aaf6de39 |grep is_public
| is_public        | False

# glance image-update 04ab89ab-e4e7-4389-bd46-e9e6aaf6de39 --is-public True

The default implementation of this feature is at:

https://github.com/openstack/cinder/blob/master/cinder/volume/driver.py

https://github.com/openstack/cinder/blob/master/cinder/image/image_utils.py