The cloud operator assigns roles to users. Roles determine who can upload and manage images. The operator might restrict image upload and management to only cloud administrators or operators.

You can upload images through the glance image-create or glance image-create-via-import command or the Image service API. You can use the glance client for the image management. It provides mechanisms to do all operations supported by the Images API v2.

After you upload an image, you cannot change the content, but you can update the metadata.

For details about image creation, see the Virtual Machine Image Guide.

List or get details for images (glance)

To get a list of images and to get further details about a single image, use glance image-list and glance image-show commands.

$ glance image-list
+--------------------------------------+---------------------------------+
| ID                                   | Name                            |
+--------------------------------------+---------------------------------+
| dfc1dfb0-d7bf-4fff-8994-319dd6f703d7 | cirros-0.3.5-x86_64-uec         |
| a3867e29-c7a1-44b0-9e7f-10db587cad20 | cirros-0.3.5-x86_64-uec-kernel  |
| 4b916fba-6775-4092-92df-f41df7246a6b | cirros-0.3.5-x86_64-uec-ramdisk |
| d07831df-edc3-4817-9881-89141f9134c3 | myCirrosImage                   |
+--------------------------------------+---------------------------------+

$ glance image-show d07831df-edc3-4817-9881-89141f9134c3
+------------------+------------------------------------------------------+
| Field            | Value                                                |
+------------------+------------------------------------------------------+
| checksum         | 443b7623e27ecf03dc9e01ee93f67afe                     |
| container_format | ami                                                  |
| created_at       | 2016-08-11T15:07:26Z                                 |
| disk_format      | ami                                                  |
| file             | /v2/images/d07831df-edc3-4817-9881-89141f9134c3/file |
| id               | d07831df-edc3-4817-9881-89141f9134c3                 |
| min_disk         | 0                                                    |
| min_ram          | 0                                                    |
| name             | myCirrosImage                                        |
| os_hash_algo     | sha512                                               |
| os_hash_value    | 6513f21e44aa3da349f248188a44bc304a3653a04122d8fb4535 |
|                  | 423c8e1d14cd6a153f735bb0982e2161b5b5186106570c17a9e5 |
|                  | 8b64dd39390617cd5a350f78                             |
| os_hidden        | False                                                |
| owner            | d88310717a8e4ebcae84ed075f82c51e                     |
| protected        | False                                                |
| schema           | /v2/schemas/image                                    |
| size             | 13287936                                             |
| status           | active                                               |
| tags             |                                                      |
| updated_at       | 2016-08-11T15:20:02Z                                 |
| virtual_size     | None                                                 |
| visibility       | private                                              |
+------------------+------------------------------------------------------+

When viewing a list of images, you can also use grep to filter the list, as follows:

$ glance image-list | grep 'cirros'
| dfc1dfb0-d7bf-4fff-8994-319dd6f703d7 | cirros-0.3.5-x86_64-uec         |
| a3867e29-c7a1-44b0-9e7f-10db587cad20 | cirros-0.3.5-x86_64-uec-kernel  |
| 4b916fba-6775-4092-92df-f41df7246a6b | cirros-0.3.5-x86_64-uec-ramdisk |

Create or update an image (glance)

To create an image, use glance image-create:

$ glance image-create --name imageName

To update an image, you must specify its ID and use glance image-update:

$ glance image-update --property x="y" <IMAGE_ID>

The following list explains the commonly used properties that you can set or modify when using the image-create and image-update commands. For more information, refer to the OpenStack Useful Image Properties.

--architecture <ARCHITECTURE>

Operating system architecture as specified in https://docs.openstack.org/glance/latest/admin/useful-image-properties.html

--protected [True|False]

If true, image will not be deletable.

--name <NAME>

Descriptive name for the image

--instance-uuid <INSTANCE_UUID>

Metadata which can be used to record which instance this image is associated with. (Informational only, does not create an instance snapshot.)

--min-disk <MIN_DISK>

Amount of disk space (in GB) required to boot image.

--visibility <VISIBILITY>

Scope of image accessibility. Valid values: public, private, community, shared

--kernel-id <KERNEL_ID>

ID of image stored in Glance that should be used as the kernel when booting an AMI-style image.

--os-version <OS_VERSION>

Operating system version as specified by the distributor

--disk-format <DISK_FORMAT>

Format of the disk. May not be modified once an image has gone to active status. Valid values: ami, ari, aki, vhd, vhdx, vmdk, raw, qcow2, vdi, iso, ploop

--os-distro <OS_DISTRO>

Common name of operating system distribution as specified in https://docs.openstack.org/glance/latest/admin/useful-image-properties.html

--owner <OWNER>

Owner of the image. Usually, may be set by an admin only.

--ramdisk-id <RAMDISK_ID>

ID of image stored in Glance that should be used as the ramdisk when booting an AMI-style image.

--min-ram <MIN_RAM>

Amount of ram (in MB) required to boot image.

--container-format <CONTAINER_FORMAT>

Format of the container. May not be modified once an image has gone to active status. Valid values: ami, ari, aki, bare, ovf, ova, docker, compressed

--hidden [True|False]

If true, image will not appear in default image list response.

--property <key=value>

Arbitrary property to associate with image. May be used multiple times.

--remove-property key

Name of arbitrary property to remove from the image.

The following example shows the command that you would use to upload a CentOS 6.3 image in qcow2 format and configure it for public access:

$ glance image-create --disk-format qcow2 --container-format bare \
  --visibility public --file ./centos63.qcow2 --name centos63-image

The following example shows how to update an existing image with a properties that describe the disk bus, the CD-ROM bus, and the VIF model:

$ glance image-update \
    --property hw_disk_bus=scsi \
    --property hw_cdrom_bus=ide \
    --property hw_vif_model=e1000 \
    <Image-ID>

Currently the libvirt virtualization tool determines the disk, CD-ROM, and VIF device models based on the configured hypervisor type (libvirt_type in /etc/nova/nova.conf file). For the sake of optimal performance, libvirt defaults to using virtio for both disk and VIF (NIC) models. The disadvantage of this approach is that it is not possible to run operating systems that lack virtio drivers, for example, BSD, Solaris, and older versions of Linux and Windows.

If you specify a disk or CD-ROM bus model that is not supported, see the Disk_and_CD-ROM_bus_model_values_table. If you specify a VIF model that is not supported, the instance fails to launch. See the VIF_model_values_table.

The valid model values depend on the libvirt_type setting, as shown in the following tables.

Disk and CD-ROM bus model values

VIF model values