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Creating and Managing Images

Red Hat OpenStack Platform 16.2

Creating and Managing Images

OpenStack Documentation Team

Abstract

This guide provides procedures for creating and managing images, and procedures for configuring the Image service.

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Chapter 1. The Image service (glance)
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Manage images and storage in Red Hat OpenStack Platform (RHOSP).

A virtual machine image is a file that contains a virtual disk with a bootable operating system installed. Virtual machine images are supported in different formats. The following formats are available in RHOSP:

  • RAW - Unstructured disk image format.
  • QCOW2 - Disk format supported by QEMU emulator. This format includes QCOW2v3 (sometimes referred to as QCOW3), which requires QEMU 1.1 or higher.
  • ISO - Sector-by-sector copy of the data on a disk, stored in a binary file.
  • AKI - Indicates an Amazon Kernel Image.
  • AMI - Indicates an Amazon Machine Image.
  • ARI - Indicates an Amazon RAMDisk Image.
  • VDI - Disk format supported by VirtualBox virtual machine monitor and the QEMU emulator.
  • VHD - Common disk format used by virtual machine monitors from VMware, VirtualBox, and others.
  • PLOOP - A disk format supported and used by Virtuozzo to run OS containers.
  • OVA - Indicates that what is stored in the Image service (glance) is an OVA tar archive file.
  • DOCKER - Indicates that what is stored in the Image service (glance) is a Docker tar archive of the container file system.

Although ISO is not normally considered a virtual machine image format, because ISOs contain bootable file systems with an installed operating system, you use them in the same way as other virtual machine image files.

To download the official Red Hat Enterprise Linux cloud images, your account must have a valid Red Hat Enterprise Linux subscription:

If you are not logged in to the Customer Portal, a prompt opens where you must enter your Red Hat account credentials.

1.1. Understanding the Image service
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Red Hat OpenStack Platform (RHOSP) Image service (glance) features.

1.1.1. Supported Image service back ends
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The following Image service (glance) back-end scenarios are supported:

  • RBD is the default back end when you use Ceph. For more information, see Configuring Ceph Storage in the Advanced Overcloud Customization guide.
  • RBD multi-store. For more information, see Section 2.1, “Requirements of storage edge architecture”.

  • Object Storage (swift). For more information, see Using an external Object Storage cluster in the Advanced Overcloud Customization guide.

    The Image service uses the Object Storage type and back end as the default.

  • Block Storage (cinder). For more information, see Configuring cinder back end for the Image service in the Advanced Overcloud Customization guide.

  • NFS. For more information, see Configuring NFS storage in the Advanced Overcloud Customization guide.

    Important

    Although NFS is a supported Image service deployment option, more robust options are available.

    NFS is not native to the Image service. When you mount an NFS share on the Image service, the Image service does not manage the operation. The Image service writes data to the file system but is unaware that the back end is an NFS share.

    In this type of deployment, the Image service cannot retry a request if the share fails. This means that when a failure occurs on the back end, the store might enter read-only mode, or it might continue to write data to the local file system, in which case you risk data loss. To recover from this situation, you must ensure that the share is mounted and in sync, and then restart the Image service. For these reasons, Red Hat does not recommend NFS as an Image service back end.

    However, if you do choose to use NFS as an Image service back end, some of the following best practices can help to mitigate risks:

    • Use a reliable production-grade NFS back end.
    • Ensure that you have a strong and reliable connection between Controller nodes and the NFS back end: Layer 2 (L2) network connectivity is recommended.
    • Include monitoring and alerts for the mounted share.
    • Set underlying file system permissions. Write permissions must be present in the shared file system that you use as a store.
    • Ensure that the user and the group that the glance-api process runs on do not have write permissions on the mount point at the local file system. This means that the process can detect possible mount failure and put the store into read-only mode during a write attempt.

1.1.2. Image signing and verification
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Image signing and verification protects image integrity and authenticity by enabling deployers to sign images and save the signatures and public key certificates as image properties.

By taking advantage of this feature, you can do these tasks:

  • Sign an image using your private key and upload the image, the signature, and a reference to your public key certificate (the verification metadata). The Image service then verifies that the signature is valid.
  • Create an image in the Compute service, have the Compute service sign the image, and upload the image and its verification metadata. The Image service again verifies that the signature is valid.
  • Request a signed image in the Compute service. The Image service provides the image and its verification metadata, allowing the Compute service to validate the image before booting it.

For information on image signing and verification, see Validating Image Service (glance) images in the Manage Secrets with OpenStack Key Manager guide.

1.1.3. Image conversion
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Image conversion converts images by calling the task API while importing an image.

As part of the import workflow, a plugin provides the image conversion. This plugin can be activated or deactivated based on the deployer configuration. Therefore, the deployer needs to specify the preferred format of images for the deployment.

Internally, the Image service receives the bits of the image in a particular format. These bits are stored in a temporary location. The plugin is then triggered to convert the image to the target format and moved to a final destination. When the task is finished, the temporary location is deleted. As a result, the format uploaded initially is not retained by the Image service.

For more information about image conversion, see Section 1.2.8, “Enabling image conversion”

Note

The conversion can be triggered only when importing an image. It does not run when uploading an image. For example: 

$ glance image-create-via-import \
    --disk-format qcow2 \
    --container-format bare \
    --name NAME \
    --visibility public \
    --import-method web-download \
    --uri http://server/image.qcow2
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1.1.4. Interoperable image import
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The interoperable image import workflow enables you to import images in two ways:

  • Use the web-download (default) method to import images from a URI.
  • Use the glance-direct method to import images from a local file system.

Use the glance-api caching mechanism to store copies of images on Image service (glance) API servers and retrieve them automatically to improve scalability. With Image service caching, glance-api can run on multiple hosts. This means that it does not need to retrieve the same image from back end storage multiple times. Image service caching does not affect any Image service operations.

Configure Image service caching with the Red Hat OpenStack Platform director (tripleo) heat templates:

Procedure

  1. In an environment file, set the value of the GlanceCacheEnabled parameter to true, which automatically sets the flavor value to keystone+cachemanagement in the glance-api.conf heat template: 

    parameter_defaults:
    GlanceCacheEnabled: true
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  2. Include the environment file in the openstack overcloud deploy command when you redeploy the overcloud.

  3. Optional: Tune the glance_cache_pruner to an alternative frequency when you redeploy the overcloud. The following example shows a frequency of 5 minutes: 

    parameter_defaults:
  ControllerExtraConfig:
    glance::cache::pruner::minute: '*/5'
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    Adjust the frequency according to your needs to avoid file system full scenarios. Include the following elements when you choose an alternative frequency:

    • The size of the files that you want to cache in your environment.
    • The amount of available file system space.
    • The frequency at which the environment caches images.

1.1.6. Image pre-caching
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Red Hat OpenStack Platform (RHOSP) director can pre-cache images as part of the glance-api service.

The default periodic interval for image pre-caching is 300 seconds. You can increase or decrease the default interval based on your requirements.

Procedure

  1. Add a new interval with the ExtraConfig parameter in an environment file on the undercloud according to your requirements: 

    parameter_defaults:
  ControllerExtraConfig:
    glance::config::glance_api_config:
      DEFAULT/cache_prefetcher_interval:
        value: '<300>'
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    Replace <300> with the number of seconds that you want as an interval to pre-cache images.

  2. After you adjust the interval in the environment file in /home/stack/templates/, log in as the stack user and deploy the configuration: 

    $ openstack overcloud deploy --templates \
-e /home/stack/templates/<env_file>.yaml
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    Replace <env_file> with the name of the environment file that contains the ExtraConfig settings that you added.

    Important

    If you passed any extra environment files when you created the overcloud, pass them again here by using the -e option to avoid making undesired changes to the overcloud.

For more information about the openstack overcloud deploy command, see Deployment command in the Director Installation and Usage guide.

Prerequisites

To use a periodic job to pre-cache an image, you must use the glance-cache-manage command connected directly to the node where the glance_api service is running. Do not use a proxy, which hides the node that answers a service request. Because the undercloud might not have access to the network where the glance_api service is running, run commands on the first overcloud node, which is called controller-0 by default.

Complete the following prerequisite procedure to ensure that you run commands from the correct host, have the necessary credentials, and are also running the glance-cache-manage commands from inside the glance-api container.

Procedure

  1. Log in to the undercloud as the stack user and identify the provisioning IP address of controller-0: 

    (undercloud) [stack@site-undercloud-0 ~]$ openstack server list -f value -c Name -c Networks | grep controller
overcloud-controller-1 ctlplane=192.168.24.40
overcloud-controller-2 ctlplane=192.168.24.13
overcloud-controller-0 ctlplane=192.168.24.71
(undercloud) [stack@site-undercloud-0 ~]$
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  2. To authenticate to the overcloud, copy the credentials that are stored in /home/stack/overcloudrc, by default, to controller-0: 

    $ scp ~/overcloudrc heat-admin@192.168.24.71:/home/heat-admin/
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  3. Connect to controller-0: 

    $ ssh heat-admin@192.168.24.71
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  4. On controller-0 as the heat-admin user, identify the IP address of the glance_api service. In the following example, the IP address is 172.25.1.105: 

    (overcloud) [root@controller-0 ~]# grep -A 10 '^listen glance_api' /var/lib/config-data/puppet-generated/haproxy/etc/haproxy/haproxy.cfg
listen glance_api
 server central-controller0-0.internalapi.redhat.local 172.25.1.105:9292 check fall 5 inter 2000 rise 2
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  5. Because the glance-cache-manage command is only available in the glance_api container, create a script to exec into that container where the environment variables to authenticate to the overcloud are already set. Create a script called glance_pod.sh in /home/heat-admin on controller-0 with the following contents: 

    sudo podman exec -ti \
 -e NOVA_VERSION=$NOVA_VERSION \
 -e COMPUTE_API_VERSION=$COMPUTE_API_VERSION \
 -e OS_USERNAME=$OS_USERNAME \
 -e OS_PROJECT_NAME=$OS_PROJECT_NAME \
 -e OS_USER_DOMAIN_NAME=$OS_USER_DOMAIN_NAME \
 -e OS_PROJECT_DOMAIN_NAME=$OS_PROJECT_DOMAIN_NAME \
 -e OS_NO_CACHE=$OS_NO_CACHE \
 -e OS_CLOUDNAME=$OS_CLOUDNAME \
 -e no_proxy=$no_proxy \
 -e OS_AUTH_TYPE=$OS_AUTH_TYPE \
 -e OS_PASSWORD=$OS_PASSWORD \
 -e OS_AUTH_URL=$OS_AUTH_URL \
 -e OS_IDENTITY_API_VERSION=$OS_IDENTITY_API_VERSION \
 -e OS_COMPUTE_API_VERSION=$OS_COMPUTE_API_VERSION \
 -e OS_IMAGE_API_VERSION=$OS_IMAGE_API_VERSION \
 -e OS_VOLUME_API_VERSION=$OS_VOLUME_API_VERSION \
 -e OS_REGION_NAME=$OS_REGION_NAME \
glance_api /bin/bash
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  6. Source the overcloudrc file and run the glance_pod.sh script to exec into the glance_api container with the necessary environment variables to authenticate to the overcloud Controller node. 

    [heat-admin@controller-0 ~]$ source overcloudrc
(overcloudrc) [heat-admin@central-controller-0 ~]$ bash glance_pod.sh
()[glance@controller-0 /]$
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  7. Use a command such as glance image-list to verify that the container can run authenticated commands against the overcloud. 

    ()[glance@controller-0 /]$ glance image-list
+--------------------------------------+----------------------------------+
| ID                                   | Name                             |
+--------------------------------------+----------------------------------+
| ad2f8daf-56f3-4e10-b5dc-d28d3a81f659 | cirros-0.4.0-x86_64-disk.img       |
+--------------------------------------+----------------------------------+
()[glance@controller-0 /]$
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Procedure

  1. As the admin user, queue an image to cache: 

    $ glance-cache-manage --host=<host_ip> queue-image <image_id>
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    • Replace <host_ip> with the IP address of the Controller node where the glance-api container is running.

    • Replace <image_id> with the ID of the image that you want to queue.

      When you have queued the images that you want to pre-cache, the cache_images periodic job prefetches all queued images concurrently.

      Note

      Because the image cache is local to each node, if your Red Hat OpenStack Platform is deployed with HA (with 3, 5, or 7 Controllers) then you must specify the host address with the --host option when you run the glance-cache-manage command.

  2. Run the following command to view the images in the image cache: 

    $ glance-cache-manage --host=<host_ip> list-cached
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    Replace <host_ip> with the IP address of the host in your environment.

Related information

You can use additional glance-cache-manage commands for the following purposes:

  • list-cached to list all images that are currently cached.
  • list-queued to list all images that are currently queued for caching.
  • queue-image to queue an image for caching.
  • delete-cached-image to purge an image from the cache.
  • delete-all-cached-images to remove all images from the cache.
  • delete-queued-image to delete an image from the cache queue.
  • delete-all-queued-images to delete all images from the cache queue.

With the Image service (glance) API, you can use sparse image upload to reduce network traffic and save storage space. This feature is particularly useful in distributed compute node (DCN) environments. With a sparse image file, the Image service does not write null byte sequences. The Image service writes data with a given offset. Storage back ends interpret these offsets as null bytes that do not actually consume storage space.

Limitations

  • Sparse image upload is supported only with Ceph RBD.
  • Sparse image upload is not supported for file systems.
  • Sparseness is not maintained during the transfer between the client and the Image service API. The image is sparsed at the Image service API level.

Prerequisites

  • Your Red Hat OpenStack Platform (RHOSP) deployment uses RBD for the Image service back end.

Procedure

  1. Log in to the undercloud node as the stack user.

  2. Source the stackrc credentials file: 

    $ source stackrc
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  3. Create an environment file with the following content: 

    parameter_defaults:
    GlanceSparseUploadEnabled: true
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  4. Add your new environment file to the stack with your other environment files and deploy the overcloud: 

    $ openstack overcloud deploy \
--templates \
…
-e <existing_overcloud_environment_files> \
-e <new_environment_file>.yaml \
…
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    For more information about uploading images, see Section 1.2.2, “Upload an image”.

Verification

You can import an image and check its size to verify sparse image upload.

  1. Download the image file locally: 

    $ wget <file_location>/<file_name>
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    Replace <file_location> with the location of the file. Replace <file_name> with the name of the file.

    The following procedure uses example commands. Replace the values with those from your environment where appropriate. 

    $ wget https://cloud.centos.org/centos/6/images/CentOS-6-x86_64-GenericCloud-1508.qcow2
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  2. Check the disk size and the virtual size of the image that you want to upload: 

     qemu-img info <file_name>
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    The following procedure uses example commands. Replace the values with those from your environment where appropriate. 

    $ qemu-img info CentOS-6-x86_64-GenericCloud-1508.qcow2

image: CentOS-6-x86_64-GenericCloud-1508.qcow2
file format: qcow2
virtual size: 8 GiB (8589934592 bytes)
disk size: 1.09 GiB
cluster_size: 65536
Format specific information:
compat: 0.10
refcount bits: 1
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  3. Import the image: 

    $ glance image-create-via-import --disk-format qcow2 --container-format bare --name centos_1 --file <file_name>
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  4. Record the image ID. It is required in a subsequent step.

  5. Verify that the image is imported and in an active state: 

    $ openstack image show <image_id>
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  6. From a Ceph Storage node, verify that the size of the image is less than the virtual size from the output of step 1: 

    $ sudo rbd -p images diff <image_id> | awk '{ SUM += $2 } END { print SUM/1024/1024/1024 " GB" }'

1.03906 GB
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  7. Optional: You can confirm that rbd_thin_provisioning is configured in the glance configuration file on the Controller nodes:

    1. Use SSH to access a Controller node: 

      $ ssh -A -t heat-admin@<controller_node_IP_address>
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    2. Confirm that rbd_thin_provisioning equals True on that Controller node: 

      $ sudo podman exec -it glance_api sh -c 'grep ^rbd_thin_provisioning /etc/glance/glance-api.conf'
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1.1.8. Secure metadef APIs
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In Red Hat OpenStack Platform (RHOSP), users can define key value pairs and tag metadata with metadata definition (metadef) APIs. Currently, there is no limit on the number of metadef namespaces, objects, properties, resources, or tags that users can create.

Metadef APIs can leak information to unauthorized users. A malicious user can exploit the lack of restrictions and fill the Image service (glance) database with unlimited resources, which can create a Denial of Service (DoS) style attack.

Image service policies control metadef APIs. However, the default policy setting for metadef APIs allows all users to create or read the metadef information. Because metadef resources are not isolated to the owner, metadef resources with potentially sensitive names, such as internal infrastructure details or customer names, can expose that information to malicious users.

To make the Image service (glance) more secure, restrict metadef modification APIs to admin-only access by default in your Red Hat OpenStack Platform (RHOSP) deployments.

Procedure

  1. As a cloud administrator, create a separate heat template environment file, such as lock-down-glance-metadef-api.yaml, to contain policy overrides for the Image service metadef API: 

    ...
parameter_defaults:
  GlanceApiPolicies: {
	glance-metadef_default: { key: 'metadef_default', value: '' },
	glance-metadef_admin: { key: 'metadef_admin', value: 'role:admin' },
	glance-get_metadef_namespace: { key: 'get_metadef_namespace', value: 'rule:metadef_default' },
	glance-get_metadef_namespaces: { key: 'get_metadef_namespaces', value: 'rule:metadef_default' },
	glance-modify_metadef_namespace: { key: 'modify_metadef_namespace', value: 'rule:metadef_admin' },
	glance-add_metadef_namespace: { key: 'add_metadef_namespace', value: 'rule:metadef_admin' },
	glance-delete_metadef_namespace: { key: 'delete_metadef_namespace', value: 'rule:metadef_admin' },
	glance-get_metadef_object: { key: 'get_metadef_object', value: 'rule:metadef_default' },
	glance-get_metadef_objects: { key: 'get_metadef_objects', value: 'rule:metadef_default' },
	glance-modify_metadef_object: { key: 'modify_metadef_object', value: 'rule:metadef_admin' },
	glance-add_metadef_object: { key: 'add_metadef_object', value: 'rule:metadef_admin' },
	glance-delete_metadef_object: { key: 'delete_metadef_object', value: 'rule:metadef_admin' },
	glance-list_metadef_resource_types: { key: 'list_metadef_resource_types', value: 'rule:metadef_default' },
	glance-get_metadef_resource_type: { key: 'get_metadef_resource_type', value: 'rule:metadef_default' },
	glance-add_metadef_resource_type_association: { key: 'add_metadef_resource_type_association', value: 'rule:metadef_admin' },
	glance-remove_metadef_resource_type_association: { key: 'remove_metadef_resource_type_association', value: 'rule:metadef_admin' },
	glance-get_metadef_property: { key: 'get_metadef_property', value: 'rule:metadef_default' },
	glance-get_metadef_properties: { key: 'get_metadef_properties', value: 'rule:metadef_default' },
	glance-modify_metadef_property: { key: 'modify_metadef_property', value: 'rule:metadef_admin' },
	glance-add_metadef_property: { key: 'add_metadef_property', value: 'rule:metadef_admin' },
	glance-remove_metadef_property: { key: 'remove_metadef_property', value: 'rule:metadef_admin' },
	glance-get_metadef_tag: { key: 'get_metadef_tag', value: 'rule:metadef_default' },
	glance-get_metadef_tags: { key: 'get_metadef_tags', value: 'rule:metadef_default' },
	glance-modify_metadef_tag: { key: 'modify_metadef_tag', value: 'rule:metadef_admin' },
	glance-add_metadef_tag: { key: 'add_metadef_tag', value: 'rule:metadef_admin' },
	glance-add_metadef_tags: { key: 'add_metadef_tags', value: 'rule:metadef_admin' },
	glance-delete_metadef_tag: { key: 'delete_metadef_tag', value: 'rule:metadef_admin' },
	glance-delete_metadef_tags: { key: 'delete_metadef_tags', value: 'rule:metadef_admin' }
  }

…
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    For information about policies and policy syntax, see this Policies chapter.

  2. Include the environment file that contains the policy overrides in the deployment command with the -e option when you deploy the overcloud: 

    $ openstack overcloud deploy -e lock-down-glance-metadef-api.yaml
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1.1.8.2. Enabling metadef APIs
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If you previously restricted metadata definition (metadef) APIs or want to relax the new defaults, you can override metadef modification policies to allow users to update their respective resources.

Important

Cloud administrators with users who depend on write access to the metadef APIs can make those APIs accessible to all users. In this type of configuration, however, there is the potential to unintentionally leak sensitive resource names, such as customer names and internal projects. Administrators must audit their systems to identify previously created resources that might be vulnerable even if only read access is enabled for all users.

Procedure

  1. As a cloud administrator, log in to the undercloud and create a file for policy overrides. For example: 

    $ cat open-up-glance-api-metadef.yaml
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  2. Configure the policy override file to allow metadef API read-write access to all users: 

    GlanceApiPolicies: {
    glance-metadef_default: { key: 'metadef_default', value: '' },
    glance-get_metadef_namespace: { key: 'get_metadef_namespace', value: 'rule:metadef_default' },
    glance-get_metadef_namespaces: { key: 'get_metadef_namespaces', value: 'rule:metadef_default' },
    glance-modify_metadef_namespace: { key: 'modify_metadef_namespace', value: 'rule:metadef_default' },
    glance-add_metadef_namespace: { key: 'add_metadef_namespace', value: 'rule:metadef_default' },
    glance-delete_metadef_namespace: { key: 'delete_metadef_namespace', value: 'rule:metadef_default' },
    glance-get_metadef_object: { key: 'get_metadef_object', value: 'rule:metadef_default' },
    glance-get_metadef_objects: { key: 'get_metadef_objects', value: 'rule:metadef_default' },
    glance-modify_metadef_object: { key: 'modify_metadef_object', value: 'rule:metadef_default' },
    glance-add_metadef_object: { key: 'add_metadef_object', value: 'rule:metadef_default' },
    glance-delete_metadef_object: { key: 'delete_metadef_object', value: 'rule:metadef_default' },
    glance-list_metadef_resource_types: { key: 'list_metadef_resource_types', value: 'rule:metadef_default' },
    glance-get_metadef_resource_type: { key: 'get_metadef_resource_type', value: 'rule:metadef_default' },
    glance-add_metadef_resource_type_association: { key: 'add_metadef_resource_type_association', value: 'rule:metadef_default' },
    glance-remove_metadef_resource_type_association: { key: 'remove_metadef_resource_type_association', value: 'rule:metadef_default' },
    glance-get_metadef_property: { key: 'get_metadef_property', value: 'rule:metadef_default' },
    glance-get_metadef_properties: { key: 'get_metadef_properties', value: 'rule:metadef_default' },
    glance-modify_metadef_property: { key: 'modify_metadef_property', value: 'rule:metadef_default' },
    glance-add_metadef_property: { key: 'add_metadef_property', value: 'rule:metadef_default' },
    glance-remove_metadef_property: { key: 'remove_metadef_property', value: 'rule:metadef_default' },
    glance-get_metadef_tag: { key: 'get_metadef_tag', value: 'rule:metadef_default' },
    glance-get_metadef_tags: { key: 'get_metadef_tags', value: 'rule:metadef_default' },
    glance-modify_metadef_tag: { key: 'modify_metadef_tag', value: 'rule:metadef_default' },
    glance-add_metadef_tag: { key: 'add_metadef_tag', value: 'rule:metadef_default' },
    glance-add_metadef_tags: { key: 'add_metadef_tags', value: 'rule:metadef_default' },
    glance-delete_metadef_tag: { key: 'delete_metadef_tag', value: 'rule:metadef_default' },
    glance-delete_metadef_tags: { key: 'delete_metadef_tags', value: 'rule:metadef_default' }
  }
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    Note

    You must configure all metadef policies to use rule:metadef_default. For information about policies and policy syntax, see this Policies chapter.

  3. Include the new policy file in the deployment command with the -e option when you deploy the overcloud: 

    $ openstack overcloud deploy -e open-up-glance-api-metadef.yaml
    Copy to Clipboard Toggle word wrap

1.2. Manage images
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The Image service (glance) provides discovery, registration, and delivery services for disk and server images. It provides the ability to copy or snapshot a server image, and immediately store it. You can use stored images as a template to commission new servers quickly and more consistently than installing a server operating system and individually configuring services.

1.2.1. Creating an image
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Manually create Red Hat OpenStack Platform (RHOSP) compatible images in the QCOW2 format by using Red Hat Enterprise Linux 7 ISO files, Red Hat Enterprise Linux 6 ISO files, or Windows ISO files.

You can use a ready RHEL KVM guest QCOW2 image:

These images are configured with cloud-init and must take advantage of ec2-compatible metadata services for provisioning SSH keys to function correctly.

Ready Windows KVM guest QCOW2 images are not available.

Note

For the KVM guest images:

  • The root account in the image is disabled, but sudo access is granted to a special user named cloud-user.
  • There is no root password set for this image.

The root password is locked in /etc/shadow by placing !! in the second field.

For a RHOSP instance, generate an ssh keypair from the RHOSP dashboard or command line and use that key combination to perform an SSH public authentication to the instance as root.

When the instance is launched, this public key is injected to it. You can then authenticate by using the private key that you download when you create the keypair.

If you want to create custom Red Hat Enterprise Linux or Windows images, see Create a Red Hat Enterprise Linux 7 Image, Create a Red Hat Enterprise Linux 6 Image, or Section 1.2.1.2.3, “Create a Windows image”.

Prerequisites

  • Linux host machine to create an image. This can be any machine on which you can install and run the Linux packages except for the undercloud or the overcloud.

  • The advanced-virt repository is enabled: 

    $ sudo subscription-manager repos --enable=advanced-virt-for-rhel-8-x86_64-rpms
    Copy to Clipboard Toggle word wrap

  • libvirt, virt-manager to install all packages necessary to create a guest operating system: 

    $ sudo dnf module install -y virt
    Copy to Clipboard Toggle word wrap

  • Libguestfs tools to install a set of tools to access and modify virtual machine images: 

    $ sudo dnf install -y libguestfs-tools-c
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  • A Red Hat Enterprise Linux 7 or 6 ISO file. For more information, see RHEL 7.2 Binary DVD or RHEL 6.8 Binary DVD or a Windows ISO file. If you do not have a Windows ISO file, see the Microsoft Evaluation Center to download an evaluation image.
  • Text editor, if you want to change the kickstart files (RHEL only).
Important

If you install the libguestfs-tools package on the undercloud, disable iscsid.socket to avoid port conflicts with the tripleo_iscsid service on the undercloud: 

$ sudo systemctl disable --now iscsid.socket
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Manually create a Red Hat OpenStack Platform (RHOSP) compatible image in the QCOW2 format by using a Red Hat Enterprise Linux 7 ISO file.

Note

You must run all commands with the [root@host]# on your host machine.

  1. Start the installation by using virt-install: 

    [root@host]# qemu-img create -f qcow2 rhel7.qcow2 8G
[root@host]# virt-install --virt-type kvm --name rhel7 --ram 2048 \
--cdrom /tmp/rhel-server-7.2-x86_64-dvd.iso \
--disk rhel7.qcow2,format=qcow2 \
--network=bridge:virbr0 --graphics vnc,listen=0.0.0.0 \
--noautoconsole --os-type=linux --os-variant=rhel7
    Copy to Clipboard Toggle word wrap

    This launches an instance and starts the installation process.

    Note

    If the instance does not launch automatically, run the virt-viewer command to view the console: 

    [root@host]# virt-viewer rhel7
    Copy to Clipboard Toggle word wrap

  2. Configure the instance:

    1. At the initial Installer boot menu, select Install Red Hat Enterprise Linux 7.
    2. Choose the appropriate Language and Keyboard options.
    3. When prompted about which type of devices your installation uses, select Auto-detected installation media.
    4. When prompted about which type of installation destination, select Local Standard Disks. For other storage options, select Automatically configure partitioning.
    5. For software selection, select Minimal Install.
    6. For network and host name, select eth0 for network and choose a host name for your device. The default host name is localhost.localdomain.

    7. Enter a password in the Root Password field and enter the same password again in the Confirm field.

      Result
      The installation process completes and the Complete! screen is displayed.
  3. After the installation is complete, reboot the instance and log in as the root user.

  4. Update the /etc/sysconfig/network-scripts/ifcfg-eth0 file so that it contains only the following values: 

    TYPE=Ethernet
DEVICE=eth0
ONBOOT=yes
BOOTPROTO=dhcp
NM_CONTROLLED=no
    Copy to Clipboard Toggle word wrap
  5. Reboot the machine.

  6. Register the machine with the Content Delivery Network. 

    # sudo subscription-manager register
# sudo subscription-manager attach --pool=Valid-Pool-Number-123456
# sudo subscription-manager repos --enable=rhel-7-server-rpms
    Copy to Clipboard Toggle word wrap

  7. Update the system: 

    # dnf -y update
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  8. Install the cloud-init packages: 

    # dnf install -y cloud-utils-growpart cloud-init
    Copy to Clipboard Toggle word wrap

  9. Edit the /etc/cloud/cloud.cfg configuration file and under cloud_init_modules add: 

    - resolv-conf
    Copy to Clipboard Toggle word wrap

    The resolv-conf option automatically configures the resolv.conf when an instance boots for the first time. This file contains information related to the instance such as nameservers, domain and other options.

  10. Add the following line to /etc/sysconfig/network to avoid problems accessing the EC2 metadata service: 

    NOZEROCONF=yes
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  11. To ensure that the console messages appear in the Log tab on the dashboard and the nova console-log output, add the following boot option to the /etc/default/grub file: 

    GRUB_CMDLINE_LINUX_DEFAULT="console=tty0 console=ttyS0,115200n8"
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  12. Run the grub2-mkconfig command: 

    # grub2-mkconfig -o /boot/grub2/grub.cfg
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    The output is as follows: 

    Generating grub configuration file ...
Found linux image: /boot/vmlinuz-3.10.0-229.7.2.el7.x86_64
Found initrd image: /boot/initramfs-3.10.0-229.7.2.el7.x86_64.img
Found linux image: /boot/vmlinuz-3.10.0-121.el7.x86_64
Found initrd image: /boot/initramfs-3.10.0-121.el7.x86_64.img
Found linux image: /boot/vmlinuz-0-rescue-b82a3044fb384a3f9aeacf883474428b
Found initrd image: /boot/initramfs-0-rescue-b82a3044fb384a3f9aeacf883474428b.img
done
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  13. Deregister the instance so that the resulting image does not contain the subscription details for this instance: 

    # subscription-manager repos --disable=*
# subscription-manager unregister
# dnf clean all
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  14. Power off the instance: 

    # poweroff
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  15. Reset and clean the image by using the virt-sysprep command so that it can be used to create instances without issues: 

    [root@host]# virt-sysprep -d rhel7
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  16. Reduce the image size by converting any free space within the disk image back to free space within the host: 

    [root@host]# virt-sparsify --compress /tmp/rhel7.qcow2 rhel7-cloud.qcow2
    Copy to Clipboard Toggle word wrap

    This creates a new rhel7-cloud.qcow2 file in the location from where the command is run.

The rhel7-cloud.qcow2 image file is ready to be uploaded to the Image service. For more information about uploading this image to your RHOSP deployment by using the dashboard, see Section 1.2.2, “Upload an image”.

Manually create a Red Hat OpenStack Platform (RHOSP) compatible image in the QCOW2 format by using a Red Hat Enterprise Linux 6 ISO file.

Note

You must run all commands with the [root@host]# on your host machine.

  1. Start the installation by using virt-install: 

    [root@host]# qemu-img create -f qcow2 rhel6.qcow2 4G
[root@host]# virt-install --connect=qemu:///system --network=bridge:virbr0 \
--name=rhel6 --os-type linux --os-variant rhel6 \
--disk path=rhel6.qcow2,format=qcow2,size=10,cache=none \
--ram 4096 --vcpus=2 --check-cpu --accelerate \
--hvm --cdrom=rhel-server-6.8-x86_64-dvd.iso
    Copy to Clipboard Toggle word wrap

    This launches an instance and starts the installation process.

    Note

    If the instance does not launch automatically, run the virt-viewer command to view the console: 

    [root@host]# virt-viewer rhel6
    Copy to Clipboard Toggle word wrap

  2. Configure the instances:

    1. At the initial Installer boot menu, select Install or upgrade an existing system and follow the installation prompts. Accept the defaults.

      The disk installer provides an option to test your installation media before installation. Select OK to run the test or Skip to proceed without testing.

    2. Choose the appropriate Language and Keyboard options.
    3. When prompted about which type of devices your installation uses, select Basic Storage Devices.
    4. Choose a host name for your device. The default host name is localhost.localdomain.
    5. Set the timezone and root password.
    6. Based on the space on the disk, choose the type of installation you want from the options in the Which type of installation would you like? window.
    7. Choose the Basic Server install, which installs an SSH server.
    8. The installation process completes and the Congratulations, your Red Hat Enterprise Linux installation is complete screen is displayed.
  3. Reboot the instance and log in as the root user.

  4. Update the /etc/sysconfig/network-scripts/ifcfg-eth0 file so that it contains only the following values: 

    TYPE=Ethernet
DEVICE=eth0
ONBOOT=yes
BOOTPROTO=dhcp
NM_CONTROLLED=no
    Copy to Clipboard Toggle word wrap
  5. Reboot the machine.

  6. Register the machine with the Content Delivery Network: 

    # sudo subscription-manager register
# sudo subscription-manager attach --pool=Valid-Pool-Number-123456
# sudo subscription-manager repos --enable=rhel-6-server-rpms
    Copy to Clipboard Toggle word wrap

  7. Update the system: 

    # dnf -y update
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  8. Install the cloud-init packages: 

    # dnf install -y cloud-utils-growpart cloud-init
    Copy to Clipboard Toggle word wrap

  9. Edit the /etc/cloud/cloud.cfg configuration file and add the following content under cloud_init_modules. 

    - resolv-conf
    Copy to Clipboard Toggle word wrap

    The resolv-conf option automatically configures the resolv.conf configuration file when an instance boots for the first time. This file contains information related to the instance such as nameservers, domain, and other options.

  10. To prevent network issues, create /etc/udev/rules.d/75-persistent-net-generator.rules: 

    # echo "#" > /etc/udev/rules.d/75-persistent-net-generator.rules
    Copy to Clipboard Toggle word wrap

    This prevents /etc/udev/rules.d/70-persistent-net.rules file from being created. If /etc/udev/rules.d/70-persistent-net.rules is created, networking might not function correctly when you boot from snapshots, the network interface is created as eth1 rather than eth0 and the IP address is not assigned.

  11. Add the following line to /etc/sysconfig/network to avoid problems accessing the EC2 metadata service: 

    NOZEROCONF=yes
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  12. To ensure that the console messages appear in the Log tab on the dashboard and the nova console-log output, add the following boot option to the /etc/grub.conf file: 

    console=tty0 console=ttyS0,115200n8
    Copy to Clipboard Toggle word wrap

  13. Deregister the virtual machine so that the resulting image does not contain the same subscription details for this instance: 

    # subscription-manager repos --disable=*
# subscription-manager unregister
# dnf clean all
    Copy to Clipboard Toggle word wrap

  14. Power off the instance: 

    # poweroff
    Copy to Clipboard Toggle word wrap

  15. Reset and clean the image by using the virt-sysprep command so that it can be used to create instances without issues: 

    [root@host]# virt-sysprep -d rhel6
    Copy to Clipboard Toggle word wrap

  16. Reduce image size by using the virt-sparsify command. This command converts any free space within the disk image back to free space within the host: 

    [root@host]# virt-sparsify --compress rhel6.qcow2 rhel6-cloud.qcow2
    Copy to Clipboard Toggle word wrap

    This creates a new rhel6-cloud.qcow2 file in the location from where the command is run.

    Note

    You must manually resize the partitions of instances based on the image in accordance with the disk space in the flavor that is applied to the instance.

The rhel6-cloud.qcow2 image file is ready to be uploaded to the Image service. For more information about uploading this image to your RHOSP deployment by using the dashboard, see Section 1.2.2, “Upload an image”.

1.2.1.2.3. Create a Windows image
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Manually create a Red Hat OpenStack Platform (RHOSP) compatible image in the QCOW2 format by using a Windows ISO file.

Note

You must run all commands with the [root@host]# on your host machine.

Procedure

  1. Start the installation by using virt-install: 

    [root@host]# virt-install --name=<name> \
--disk size=<size> \
--cdrom=<path> \
--os-type=windows \
--network=bridge:virbr0 \
--graphics spice \
--ram=<ram>
    Copy to Clipboard Toggle word wrap

    Replace the following values of the virt-install parameters:

    • <name> — the name that the Windows instance has.
    • <size> — disk size in GB.
    • <path> — the path to the Windows installation ISO file.

    • <RAM> — the requested amount of RAM in MB.

      Note

      The --os-type=windows parameter ensures that the clock is configured correctly for the Windows guest, and enables its Hyper-V enlightenment features. You must also set os_type=windows in the image metadata before uploading the image to the Image service.

  2. virt-install saves the guest image as /var/lib/libvirt/images/<name>.qcow2 by default. If you want to keep the guest image elsewhere, change the parameter of the --disk option: 

    --disk path=<filename>,size=<size>
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    Replace <filename> with the name of the file that stores the instance image, and optionally its path. For example, path=win8.qcow2,size=8 creates an 8 GB file named win8.qcow2 in the current working directory.

    Tip

    If the guest does not launch automatically, run the virt-viewer command to view the console: 

    [root@host]# virt-viewer <name>
    Copy to Clipboard Toggle word wrap

    For more information about how to install Windows, see the relevant Microsoft documentation.

  3. To allow the newly installed Windows system to use the virtualized hardware, you might need to install VirtIO drivers. To so do, first install the image, which you must attach as a CD-ROM drive to the Windows instance. To install the virtio-win package you must add the VirtIO ISO image to the instance, and install the VirtIO drivers. For more information, see Installing KVM paravirtualized drivers for Windows virtual machines in the Configuring and managing virtualization guide.

  4. To complete the configuration, download and execute Cloudbase-Init on the Windows system. At the end of the installation of Cloudbase-Init, select the Run Sysprep and Shutdown checkboxes. The Sysprep tool makes the guest unique by generating an OS ID, which is used by certain Microsoft services.

    Important

    Red Hat does not provide technical support for Cloudbase-Init. If you encounter an issue, see Contact Cloudbase Solutions.

When the Windows system shuts down, the <name>.qcow2 image file is ready to be uploaded to the Image service. For more information about uploading this image to your RHOSP deployment by using the dashboard or the command line, see Section 1.2.2, “Upload an image”.

Note

libosinfo data

The Compute Service has deprecated support for using libosinfo data to set default device models. Instead, use the following image metadata properties to configure the optimal virtual hardware for an instance:

  • os_distro
  • os_version
  • hw_cdrom_bus
  • hw_disk_bus
  • hw_scsi_model
  • hw_vif_model
  • hw_video_model
  • hypervisor_type

For more information about these metadata properties, see Image configuration parameters.

1.2.2. Upload an image
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  1. In the dashboard, select Project > Compute > Images.
  2. Click Create Image.
  3. Fill out the values, and click Create Image.
Expand
Table 1.1. Image options
FieldNotes

Name

Name for the image. The name must be unique within the project.

Description

Brief description to identify the image.

Image Source

Image source: Image Location or Image File. Based on your selection, the next field is displayed.

Image Location or Image File

  • Select Image Location option to specify the image location URL.
  • Select Image File option to upload an image from the local disk.

Format

Image format (for example, qcow2).

Architecture

Image architecture. For example, use i686 for a 32-bit architecture or x86_64 for a 64-bit architecture.

Minimum Disk (GB)

Minimum disk size required to boot the image. If this field is not specified, the default value is 0 (no minimum).

Minimum RAM (MB)

Minimum memory size required to boot the image. If this field is not specified, the default value is 0 (no minimum).

Public

If selected, makes the image public to all users with access to the project.

Protected

If selected, ensures only users with specific permissions can delete this image.

When the image has been successfully uploaded, its status is active, which indicates that the image is available for use. Note that the Image service can handle even large images that take a long time to upload — longer than the lifetime of the Identity service token which was used when the upload was initiated. This is due to the fact that the Image service first creates a trust with the Identity service so that a new token can be obtained and used when the upload is complete and the status of the image is to be updated.

Note

You can also use the glance image-create command with the property option to upload an image. More values are available on the command line. For a complete listing, see Appendix A, Image configuration parameters.

1.2.3. Update an image
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  1. In the dashboard, select Project > Compute > Images.

  2. Click Edit Image from the list.

    Note

    The Edit Image option is available only when you log in as an admin user. When you log in as a demo user, you have the option to Launch an instance or Create Volume.

  3. Update the fields and click Update Image . You can update the following values - name, description, kernel ID, ramdisk ID, architecture, format, minimum disk, minimum RAM, public, protected.
  4. Click the drop-down menu and select Update Metadata option.
  5. Specify metadata by adding items from the left column to the right one. In the left column, there are metadata definitions from the Image Service Metadata Catalog. Select Other to add metadata with the key of your choice and click Save when finished.
Note

You can also use the glance image-update command with the property option to update an image. More values are available on the command line; for a complete listing, see Appendix A, Image configuration parameters.

1.2.4. Importing an image
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You can import images to the Image service (glance) by using one of the following two methods:

  • Use web-download to import an image from a URI.
  • Use glance-direct to import an image from a local file system.

The web-download method is enabled by default. The cloud administrator configures import methods. You can run the glance import-info command to list available import options.

1.2.4.1. Import an image from a remote URI
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You can use the web-download method to copy an image from a remote URI.

  1. Create an image and specify the URI of the image to import: 

    $ glance image-create-via-import \
    --container-format <CONTAINER FORMAT> \
    --disk-format <DISK-FORMAT> \
    --name <NAME> \
    --import-method web-download \
    --uri <URI>
    Copy to Clipboard Toggle word wrap
    • Replace <CONTAINER FORMAT> with the container format that you are setting set for your image (None, ami, ari, aki, bare, ovf, ova, docker).
    • Replace <DISK-FORMAT> with the disk format that you are setting set for your image (None, ami, ari, aki, vhd, vhdx, vmdk, raw, qcow2, vdi, iso, ploop).
    • Replace <NAME> with a descriptive name for your image.
    • Replace <URI> with the URI of your image.

  2. You can check the availability of the image by using the glance image-show <IMAGE_ID> command.

    • Replace <IMAGE_ID> with the ID you provided during image creation.

The Image service web download method uses a two-stage process to perform the import:

  1. The web download method creates an image record.
  2. The web download method retrieves the image from the specified URI.

The URI is subject to optional denylist and allowlist filtering.

The Image Property Injection plugin may inject metadata properties to the image. These injected properties determine which compute nodes the image instances are launched on.

1.2.4.2. Import an image from a local volume
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The glance-direct method creates an image record, which generates an image ID. After the image is uploaded to the Image service from a local volume, it is stored in a staging area and is made active after it passes any configured checks. The glance-direct method requires a shared staging area when used in a highly available (HA) configuration.

Note

Image uploads that use the glance-direct method can fail in a HA environment if a common staging area is not present. In a HA active-active environment, API calls are distributed to the Image service controllers. The download API call can be sent to a different controller than the API call to upload the image.

The glance-direct method uses three different calls to import an image:

  • glance image-create
  • glance image-stage
  • glance image-import

You can use the glance image-create-via-import command to perform all three of these calls in one command: 

$ glance image-create-via-import --container-format <CONTAINER FORMAT> --disk-format <DISK-FORMAT> --name <NAME> --file </PATH/TO/IMAGE>
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  • Replace <CONTAINER FORMAT>, <DISK-FORMAT>, <NAME>, and </PATH/TO/IMAGE> with the relevant values for your image.

After the image moves from the staging area to the back-end location, the image is listed. However, it might take some time for the image to become active.

You can check the availability of the image by using the glance image-show <IMAGE_ID> command.

  • Replace <IMAGE_ID with the ID you provided during image creation.

1.2.5. Delete an image
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  1. In the dashboard, select Project > Compute > Images.
  2. Select the image you want to delete and click Delete Images.

1.2.6. Hide or unhide an image
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You can hide public images from normal listings presented to users. For instance, you can hide obsolete CentOS 7 images and show only the latest version to simplify the user experience. Users can discover and use hidden images.

To hide an image: 

glance image-update <image_id> --hidden 'true'
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To create a hidden image, add the --hidden argument to the glance image-create command.

To unhide an image: 

glance image-update <image_id> --hidden 'false'
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1.2.7. Show hidden images
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To list hidden images: 

glance image-list --hidden 'true'
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1.2.8. Enabling image conversion
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With the GlanceImageImportPlugins parameter enabled, you can upload a QCOW2 image, and the Image service can convert it to RAW.

Note

Image conversion is automatically enabled when you use Red Hat Ceph Storage RBD to store images and boot Nova instances.

To enable image conversion, create an environment file that contains the following parameter value and include the new environment file with the -e option in the openstack overcloud deploy command:

+ 

parameter_defaults:
  GlanceImageImportPlugins:'image_conversion'
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1.2.9. Converting an image to RAW format
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Red Hat Ceph Storage can store, but does not support using, QCOW2 images to host virtual machine (VM) disks.

When you upload a QCOW2 image and create a VM from it, the compute node downloads the image, converts the image to RAW, and uploads it back into Ceph, which can then use it. This process affects the time it takes to create VMs, especially during parallel VM creation.

For example, when you create multiple VMs simultaneously, uploading the converted image to the Ceph cluster might impact already running workloads. The upload process can starve those workloads of IOPS and impede storage responsiveness.

To boot VMs in Ceph more efficiently (ephemeral back end or boot from volume), the glance image format must be RAW.

Procedure

  1. Converting an image to RAW might yield an image that is larger in size than the original QCOW2 image file. Run the following command before the conversion to determine the final RAW image size: 

    qemu-img info <image>.qcow2
    Copy to Clipboard Toggle word wrap

  2. Convert an image from QCOW2 to RAW format: 

    qemu-img convert -p -f qcow2 -O raw <original qcow2 image>.qcow2 <new raw image>.raw
    Copy to Clipboard Toggle word wrap

You can the configure the Image service (glance) to enable or reject disk formats by using the GlanceDiskFormats parameter.

Procedure

  1. Log in to the undercloud host as the stack user.

  2. Source the undercloud credentials file: 

    $ source ~/stackrc
    Copy to Clipboard Toggle word wrap

  3. Include the GlanceDiskFormats parameter in an environment file, for example, glance_disk_formats.yaml: 

    parameter_defaults:
  GlanceDiskFormats:
    - <disk_format>
    Copy to Clipboard Toggle word wrap

    • For example, use the following configuration to enable only RAW and ISO disk formats: 

      parameter_defaults:
  GlanceDiskFormats:
  - raw
  - iso
      Copy to Clipboard Toggle word wrap

    • Use the following example configuration to reject QCOW2 disk images: 

      parameter_defaults:
  GlanceDiskFormats:
  - raw
  - iso
  - aki
  - ari
  - ami
      Copy to Clipboard Toggle word wrap

  4. Include the environment file that contains your new configuration in the openstack overcloud deploy command with any other environment files that are relevant to your environment: 

    $ openstack overcloud deploy --templates \
  -e <overcloud_environment_files> \
  -e <new_environment_file> \
  …
    Copy to Clipboard Toggle word wrap
    • Replace <overcloud_environment_files> with the list of environment files that are part of your deployment.
    • Replace <new_environment_file> with the environment file that contains your new configuration.

For more information about the disk formats available in RHOSP, see Chapter 1, The Image service (glance).

1.2.10. Storing an image in RAW format
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With the GlanceImageImportPlugins parameter enabled, run the following command to store a previously created image in RAW format: 

$ glance image-create-via-import \
    --disk-format qcow2 \
    --container-format bare \
    --name NAME \
    --visibility public \
    --import-method web-download \
    --uri http://server/image.qcow2
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  • For --name, replace NAME with the name of the image; this is the name that will appear in glance image-list.
  • For --uri, replace http://server/image.qcow2 with the location and file name of the QCOW2 image.
Note

This command example creates the image record and imports it by using the web-download method. The glance-api downloads the image from the --uri location during the import process. If web-download is not available, glanceclient cannot automatically download the image data. Run the glance import-info command to list the available image import methods.

Chapter 2. Image service with multiple stores
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The Red Hat OpenStack Platform Image service (glance) supports using multiple stores with distributed edge architecture so that you can have an image pool at every edge site. You can copy images between the central site, which is also known as the hub site, and the edge sites.

The image metadata contains the location of each copy. For example, an image present on two edge sites is exposed as a single UUID with three locations: the central site plus the two edge sites. This means you can have copies of image data that share a single UUID on many stores. For more information about locations, see Understanding the location of images.

With an RBD image pool at every edge site, you can boot VMs quickly by using Ceph RBD copy-on-write (COW) and snapshot layering technology. This means that you can boot VMs from volumes and have live migration. For more information about layering with Ceph RBD, see Ceph block device layering in the Block Device Guide.

2.1. Requirements of storage edge architecture
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  • A copy of each image must exist in the Image service at the central location.
  • Prior to creating an instance at an edge site, you must have a local copy of the image at that edge site.
  • Images uploaded to an edge site must be copied to the central location before they can be copied to other edge sites.
  • You must use raw images when deploying a DCN architecture with Ceph storage.
  • RBD must be the storage driver for the Image, Compute and Block Storage services.
  • For each site, you must assign the same value to the NovaComputeAvailabilityZone and CinderStorageAvailabilityZone parameters.

2.2. Import an image to multiple stores
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Use the interoperable image import workflow to import image data into multiple Ceph Storage clusters. You can import images into the Image service that are available on the local file system or through a web server.

If you import an image from a web server, the image can be imported into multiple stores at once. If the image is not available on a web server, you can import the image from a local file system into the central store and then copy it to additional stores. For more information, see Copy an existing image to multiple stores.

Important

Always store an image copy on the central site, even if there are no instances using the image at the central location. For more information about importing images into the Image service, see the Distributed compute node and storage deployment guide.

2.2.1. Manage image import failures
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You can manage failures of the image import operation by using the --allow-failure parameter:

  • If the value of the --allow-failure parameter to true, the image status becomes active after the first store successfully imports the data. This is the default setting. You can view a list of stores that failed to import the image data by using the os_glance_failed_import image property.
  • If you set the value of the --allow-failure parameter to false, the image status only becomes active after all specified stores successfully import the data. Failure of any store to import the image data results in an image status of failed. The image is not imported into any of the specified stores.

2.2.2. Importing image data to multiple stores
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Because the default setting of the --allow-failure parameter is true, you do not need to include the parameter in the command if it is acceptable for some stores to fail to import the image data.

Note

This procedure does not require all stores to successfully import the image data.

Procedure

  1. Import image data to multiple, specified stores: 

    $ glance image-create-via-import \
--container-format bare \
--name IMAGE-NAME \
--import-method web-download \
--uri URI \
--stores STORE1,STORE2,STORE3
    Copy to Clipboard Toggle word wrap
    • Replace IMAGE-NAME with the name of the image you want to import.
    • Replace URI with the URI of the image.
    • Replace STORE1, STORE2, and STORE3 with the names of the stores to which you want to import the image data.
    • Alternatively, replace --stores with --all-stores true to upload the image to all the stores.
Note

The glance image-create-via-import command, which automatically converts the QCOW2 image to RAW format, works only with the web-download method. The glance-direct method is available, but it works only in deployments with a configured shared file system.

This procedure requires all stores to successfully import the image data.

Procedure

  1. Import image data to multiple, specified stores: 

    $ glance image-create-via-import \
--container-format bare \
--name IMAGE-NAME \
--import-method web-download \
--uri URI \
--stores STORE1,STORE2
    Copy to Clipboard Toggle word wrap
    • Replace IMAGE-NAME with the name of the image you want to import.
    • Replace URI with the URI of the image.
    • Replace STORE1, STORE2, and STORE3 with the names of stores to which you want to copy the image data.

    • Alternatively, replace --stores with --all-stores true to upload the image to all the stores.

      Note

      With the --allow-failure parameter set to false, the Image service does not ignore stores that fail to import the image data. You can view the list of failed stores with the image property os_glance_failed_import. For more information see Checking the progress of image import operation.

  2. Verify that the image data was added to specific stores: 

    $ glance image-show IMAGE-ID | grep stores
    Copy to Clipboard Toggle word wrap

    Replace IMAGE-ID with the ID of the original existing image.

    The output displays a comma-delimited list of stores.

2.2.4. Importing image data to a single store
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You can import image data to a single store.

Procedure

  1. Import image data to a single store: 

    $ glance image-create-via-import \
--container-format bare \
--name IMAGE-NAME \
--import-method web-download \
--uri URI \
--store STORE
    Copy to Clipboard Toggle word wrap
    • Replace IMAGE-NAME with the name of the image you want to import.
    • Replace URI with the URI of the image.

    • Replace STORE with the name of the store to which you want to copy the image data.

      Note

      If you do not include the options of --stores, --all-stores, or --store in the command, the Image service creates the image in the central store.

  2. Verify that the image data was added to specific store: 

    $ glance image-show IMAGE-ID | grep stores
    Copy to Clipboard Toggle word wrap

    Replace IMAGE-ID with the ID of the original existing image.

    The output displays a comma-delimited list of stores.

The interoperable image import workflow sequentially imports image data into stores. The size of the image, the number of stores, and the network speed between the central site and the edge sites impact how long it takes for the image import operation to complete.

You can follow the progress of the image import by looking at two image properties, which appear in notifications sent during the image import operation:

  • The os_glance_importing_to_stores property lists the stores that have not imported the image data. At the beginning of the import, all requested stores show up in the list. Each time a store successfully imports the image data, the Image service removes the store from the list.
  • The os_glance_failed_import property lists the stores that fail to import the image data. This list is empty at the beginning of the image import operation.
Note

In the following procedure, the environment has three Ceph Storage clusters: the central store and two stores at the edge, dcn0 and dcn1.

Procedure

  1. Verify that the image data was added to specific stores: 

    $ glance image-show IMAGE-ID
    Copy to Clipboard Toggle word wrap

    Replace IMAGE-ID with the ID of the original existing image.

    The output displays a comma-delimited list of stores similar to the following example snippet: 

    | os_glance_failed_import       |
| os_glance_importing_to_stores | central,dcn0,dcn1
| status                        | importing
    Copy to Clipboard Toggle word wrap

  2. Monitor the status of the image import operation. When you precede a command with watch, the command output refreshes every two seconds. 

    $ watch glance image-show IMAGE-ID
    Copy to Clipboard Toggle word wrap

    Replace IMAGE-ID with the ID of the original existing image.

    The status of the operation changes as the image import operation progresses: 

    | os_glance_failed_import       |
| os_glance_importing_to_stores | dcn0,dcn1
| status                        | importing
    Copy to Clipboard Toggle word wrap

    Output that shows that an image failed to import resembles the following example: 

    | os_glance_failed_import       | dcn0
| os_glance_importing_to_stores | dcn1
| status                        | importing
    Copy to Clipboard Toggle word wrap

    After the operation completes, the status changes to active: 

    | os_glance_failed_import       | dcn0
| os_glance_importing_to_stores |
| status                        | active
    Copy to Clipboard Toggle word wrap

2.3. Copy an existing image to multiple stores
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This feature enables you to copy existing images using Red Hat OpenStack Image service (glance) image data into multiple Ceph Storage stores at the edge by using the interoperable image import workflow.

Note

The image must be present at the central site before you copy it to any edge sites. Only the image owner or administrator can copy existing images to newly added stores.

You can copy existing image data either by setting --all-stores to true or by specifying specific stores to receive the image data.

  • The default setting for the --all-stores option is false. If --all-stores is false, you must specify which stores receive the image data by using --stores STORE1,STORE2. If the image data is already present in any of the specified stores, the request fails.
  • If you set all-stores to true, and the image data already exists in some of the stores, then those stores are excluded from the list.

After you specify which stores receive the image data, the Image service copies data from the central site to a staging area. Then the Image service imports the image data by using the interoperable image import workflow. For more information, see Importing an image to multiple stores.

Important

Red Hat recommends that administrators carefully avoid closely timed image copy requests. Two closely timed copy-image operations for the same image causes race conditions and unexpected results. Existing image data remains as it is, but copying data to new stores fails.

2.3.1. Copying an image to all stores
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Use the following procedure to copy image data to all available stores.

Procedure

  1. Copy image data to all available stores: 

    $ glance image-import IMAGE-ID \
--all-stores true \
--import-method copy-image
    Copy to Clipboard Toggle word wrap

    Replace IMAGE-ID with the name of the image you want to copy.

  2. Confirm that the image data successfully replicated to all available stores: 

    $ glance image-list --include-stores
    Copy to Clipboard Toggle word wrap

    For information about how to check the status of the image import operation, see Checking the progress of the image import operation.

2.3.2. Copying an image to specific stores
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Use the following procedure to copy image data to specific stores.

Procedure

  1. Copy image data to specific stores: 

    $ glance image-import IMAGE-ID \
--stores STORE1,STORE2 \
--import-method copy-image
    Copy to Clipboard Toggle word wrap
    • Replace IMAGE-ID with the name of the image you want to copy.
    • Replace STORE1 and STORE2 with the names of the stores to which you want to copy the image data.

  2. Confirm that the image data successfully replicated to the specified stores: 

    $ glance image-list --include-stores
    Copy to Clipboard Toggle word wrap

    For information about how to check the status of the image import operation, see Checking the progress of the image import operation.

2.4. Deleting an image from a specific store
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This feature enables you to delete an existing image copy on a specific store using Red Hat OpenStack Image service (glance).

Procedure

Delete an image from a specific store: 

$ glance stores-delete --store _STORE_ID_ _IMAGE_ID_
Copy to Clipboard Toggle word wrap
  • Replace _STORE_ID with the name of the store on which the image copy should be deleted.
  • Replace IMAGE_ID with the ID of the image you want to delete.
Warning

Using glance image-delete will permanently delete the image across all the sites. All image copies will be deleted, as well as the image instance and metadata.

2.5. Understanding the locations of images
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Although an image can be present on multiple sites, there is only a single UUID for a given image. The image metadata contains the locations of each copy. For example, an image present on two edge sites is exposed as a single UUID with three locations: the central site plus the two edge sites.

Procedure

  1. Show the sites on which a copy of the image exists: 

    $ glance image-show ID | grep "stores"

| stores |  default_backend,dcn1,dcn2
    Copy to Clipboard Toggle word wrap

    In the example, the image is present on the central site, the default_backend, and on the two edge sites dcn1 and dcn2.

  2. Alternatively, you can run the glance image-list command with the --include-stores option to see the sites where the images exist: 

    $ glance image-list --include-stores

| ID                                   | Name    | Stores

| 2bd882e7-1da0-4078-97fe-f1bb81f61b00 | cirros | default_backend,dcn1,dcn2
    Copy to Clipboard Toggle word wrap

  3. List the image locations properties to show the details of each location: 

    $ openstack image show ID -c properties

| properties |

(--- cut ---)
locations='[{'url': 'rbd://79b70c32-df46-4741-93c0-8118ae2ae284/images/2bd882e7-1da0-4078-97fe-f1bb81f61b00/snap', 'metadata': {'store': 'default_backend'}}, {'url': 'rbd://63df2767-8ddb-4e06-8186-8c155334f487/images/2bd882e7-1da0-4078-97fe-f1bb81f61b00/snap', 'metadata': {'store': 'dcn1'}}, {'url': 'rbd://1b324138-2ef9-4ef9-bd9e-aa7e6d6ead78/images/2bd882e7-1da0-4078-97fe-f1bb81f61b00/snap', 'metadata': {'store': 'dcn2'}}]',
(--- cut --)
    Copy to Clipboard Toggle word wrap

    The image properties show the different Ceph RBD URIs for the location of each image.

    In the example, the central image location URI is: 

    rbd://79b70c32-df46-4741-93c0-8118ae2ae284/images/2bd882e7-1da0-4078-97fe-f1bb81f61b00/snap', 'metadata': {'store': 'default_backend'}}
    Copy to Clipboard Toggle word wrap

    The URI is composed of the following data:

    • 79b70c32-df46-4741-93c0-8118ae2ae284 corresponds to the central Ceph FSID. Each Ceph cluster has a unique FSID.
    • The default value for all sites is images, which corresponds to the Ceph pool on which the images are stored.
    • 2bd882e7-1da0-4078-97fe-f1bb81f61b00 corresponds to the image UUID. The UUID is the same for a given image regardless of its location.
    • The metadata shows the glance store to which this location maps. In this example, it maps to the default_backend, which is the central hub site.

Appendix A. Image configuration parameters
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The following keys can be used with the property option for both the glance image-update and glance image-create commands. 

$ glance image-update IMG-UUID --property architecture=x86_64
Copy to Clipboard Toggle word wrap
Expand
Table A.1. Property keys
Specific toKeyDescriptionSupported values

All

architecture

The CPU architecture that must be supported by the hypervisor. For example, x86_64, arm, or ppc64. Run uname -m to get the architecture of a machine.

  • alpha - DEC 64-bit RISC
  • armv7l - ARM Cortex-A7 MPCore
  • cris- Ethernet, Token Ring, AXis-Code Reduced Instruction Set
  • i686 - Intel sixth-generation x86 (P6 micro architecture)
  • ia64 - Itanium
  • lm32 - Lattice Micro32
  • m68k - Motorola 68000
  • microblaze - Xilinx 32-bit FPGA (Big Endian)
  • microblazeel - Xilinx 32-bit FPGA (Little Endian)
  • mips - MIPS 32-bit RISC (Big Endian)
  • mipsel - MIPS 32-bit RISC (Little Endian)
  • mips64 - MIPS 64-bit RISC (Big Endian)
  • mips64el - MIPS 64-bit RISC (Little Endian)
  • openrisc - OpenCores RISC
  • parisc - HP Precision Architecture RISC
  • parisc64 - HP Precision Architecture 64-bit RISC
  • ppc - PowerPC 32-bit
  • ppc64 - PowerPC 64-bit
  • ppcemb - PowerPC (Embedded 32-bit)
  • s390 - IBM Enterprise Systems Architecture/390
  • s390x - S/390 64-bit
  • sh4 - SuperH SH-4 (Little Endian)
  • sh4eb - SuperH SH-4 (Big Endian)
  • sparc - Scalable Processor Architecture, 32-bit
  • sparc64 - Scalable Processor Architecture, 64-bit
  • unicore32 - Microprocessor Research and Development Center RISC Unicore32
  • x86_64 - 64-bit extension of IA-32
  • xtensa - Tensilica Xtensa configurable microprocessor core
  • xtensaeb - Tensilica Xtensa configurable microprocessor core (Big Endian)

All

hypervisor_type

The hypervisor type.

kvm, vmware

All

instance_uuid

For snapshot images, this is the UUID of the server used to create this image.

Valid server UUID

All

kernel_id

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

Valid image ID

All

os_distro

The common name of the operating system distribution in lowercase.

  • arch - Arch Linux. Do not use archlinux or org.archlinux.
  • centos - Community Enterprise Operating System. Do not use org.centos or CentOS.
  • debian - Debian. Do not use Debian or org.debian.
  • fedora - Fedora. Do not use Fedora, org.fedora, or org.fedoraproject.
  • freebsd - FreeBSD. Do not use org.freebsd, freeBSD, or FreeBSD.
  • gentoo - Gentoo Linux. Do not use Gentoo or org.gentoo.
  • mandrake - Mandrakelinux (MandrakeSoft) distribution. Do not use mandrakelinux or MandrakeLinux.
  • mandriva - Mandriva Linux. Do not use mandrivalinux.
  • mes - Mandriva Enterprise Server. Do not use mandrivaent or mandrivaES.
  • msdos - Microsoft Disc Operating System. Do not use ms-dos.
  • netbsd - NetBSD. Do not use NetBSD or org.netbsd.
  • netware - Novell NetWare. Do not use novell or NetWare.
  • openbsd - OpenBSD. Do not use OpenBSD or org.openbsd.
  • opensolaris - OpenSolaris. Do not use OpenSolaris or org.opensolaris.
  • opensuse - openSUSE. Do not use suse, SuSE, or org.opensuse.
  • rhel - Red Hat Enterprise Linux. Do not use redhat, RedHat, or com.redhat.
  • sled - SUSE Linux Enterprise Desktop. Do not use com.suse.
  • ubuntu - Ubuntu. Do not use Ubuntu, com.ubuntu, org.ubuntu, or canonical.
  • windows - Microsoft Windows. Do not use com.microsoft.server.

All

os_version

The operating system version as specified by the distributor.

Version number (for example, "11.10")

All

ramdisk_id

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

Valid image ID

All

vm_mode

The virtual machine mode. This represents the host/guest ABI (application binary interface) used for the virtual machine.

hvm-Fully virtualized. This is the mode used by QEMU and KVM.

libvirt API driver

hw_disk_bus

Specifies the type of disk controller to attach disk devices to.

scsi, virtio, ide, or usb. Note that if using iscsi, the hw_scsi_model needs to be set to virtio-scsi.

libvirt API driver

hw_cdrom_bus

Specifies the type of disk controller to attach CD-ROM devices to.

scsi, virtio, ide, or usb. If you specify iscsi, you must set the hw_scsi_model parameter to virtio-scsi.

libvirt API driver

hw_numa_nodes

Number of NUMA nodes to expose to the instance (does not override flavor definition).

Integer.

libvirt API driver

hw_numa_cpus.0

Mapping of vCPUs N-M to NUMA node 0 (does not override flavor definition).

Comma-separated list of integers.

libvirt API driver

hw_numa_cpus.1

Mapping of vCPUs N-M to NUMA node 1 (does not override flavor definition).

Comma-separated list of integers.

libvirt API driver

hw_numa_mem.0

Mapping N MB of RAM to NUMA node 0 (does not override flavor definition).

Integer

libvirt API driver

hw_numa_mem.1

Mapping N MB of RAM to NUMA node 1 (does not override flavor definition).

Integer

libvirt API driver

hw_qemu_guest_agent

Guest agent support. If set to yes, and if qemu-ga is also installed, file systems can be quiesced (frozen) and snapshots created automatically.

yes / no

libvirt API driver

hw_rng_model

Adds a random number generator (RNG) device to instances launched with this image.

The instance flavor enables the RNG device by default. To disable the RNG device, the cloud administrator must set hw_rng:allowed to False on the flavor.

The default entropy source is /dev/random. To specify a hardware RNG device, set rng_dev_path to /dev/hwrng in your Compute environment file.

virtio, or other supported device.

libvirt API driver

hw_scsi_model

Enables the use of VirtIO SCSI (virtio-scsi) to provide block device access for compute instances; by default, instances use VirtIO Block (virtio-blk). VirtIO SCSI is a para-virtualized SCSI controller device that provides improved scalability and performance, and supports advanced SCSI hardware.

virtio-scsi

libvirt API driver

hw_video_model

The video device driver for the display device to use in virtual machine instances.

Set to one of the following values to specify the supported driver to use:

  • virtio - Recommended Driver for the virtual machine display device, supported by most architectures. The VirtIO GPU driver is included in RHEL-7 and later, and Linux kernel versions 4.4 and later. If an instance kernel has the VirtIO GPU driver, then the instance can use all the VirtIO GPU features. If an instance kernel does not have the VirtIO GPU driver, the VirtIO GPU device gracefully falls back to VGA compatibility mode, which provides a working display for the instance.
  • qxl - Deprecated Driver for Spice or noVNC environments that is no longer maintained.
  • cirrus - Legacy driver.
  • vga - Use this driver for IBM Power environments.
  • gop - Not supported for QEMU/KVM environments.
  • xen - Not supported for KVM environments.
  • vmvga - Legacy driver, do not use.
  • none - Use this value to disable emulated graphics or video in virtual GPU (vGPU) instances where the driver is configured separately.

libvirt API driver

hw_video_ram

Maximum RAM for the video image. Used only if a hw_video:ram_max_mb value has been set in the flavor’s extra_specs and that value is higher than the value set in hw_video_ram.

Integer in MB (for example, 64)

libvirt API driver

hw_watchdog_action

Enables a virtual hardware watchdog device that carries out the specified action if the server hangs. The watchdog uses the i6300esb device (emulating a PCI Intel 6300ESB). If hw_watchdog_action is not specified, the watchdog is disabled.

  • disabled-The device is not attached. Allows the user to disable the watchdog for the image, even if it has been enabled using the image’s flavor. The default value for this parameter is disabled.
  • reset-Forcefully reset the guest.
  • poweroff-Forcefully power off the guest.
  • pause-Pause the guest.
  • none-Only enable the watchdog; do nothing if the server hangs.

libvirt API driver

os_command_line

The kernel command line to be used by the libvirt driver, instead of the default. For Linux Containers (LXC), the value is used as arguments for initialization. This key is valid only for Amazon kernel, ramdisk, or machine images (aki, ari, or ami).

 

libvirt API driver and VMware API driver

hw_vif_model

Specifies the model of virtual network interface device to use.

The valid options depend on the configured hypervisor.

  • KVM and QEMU: e1000, ne2k_pci, pcnet, rtl8139, and virtio.
  • VMware: e1000, e1000e, VirtualE1000, VirtualE1000e, VirtualPCNet32, VirtualSriovEthernetCard, and VirtualVmxnet.
  • Xen: e1000, netfront, ne2k_pci, pcnet, and rtl8139.

VMware API driver

vmware_adaptertype

The virtual SCSI or IDE controller used by the hypervisor.

lsiLogic, busLogic, or ide

VMware API driver

vmware_ostype

A VMware GuestID which describes the operating system installed in the image. This value is passed to the hypervisor when creating a virtual machine. If not specified, the key defaults to otherGuest.

For more information, see Images with VMware vSphere.

VMware API driver

vmware_image_version

Currently unused.

1

XenAPI driver

auto_disk_config

If true, the root partition on the disk is automatically resized before the instance boots. This value is only taken into account by the Compute service when using a Xen-based hypervisor with the XenAPI driver. The Compute service will only attempt to resize if there is a single partition on the image, and only if the partition is in ext3 or ext4 format.

true / false

libvirt API driver and XenAPI driver

os_type

The operating system installed on the image. The XenAPI driver contains logic that takes different actions depending on the value of the os_type parameter of the image. For example, for os_type=windows images, it creates a FAT32-based swap partition instead of a Linux swap partition, and it limits the injected host name to less than 16 characters.

linux or windows

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