Configuring the Image (glance) service

Configuring the Image (glance) service

In an all-in-one deployment with a single infrastructure node, the Image (glance) service uses the local file system on the target host to store images. When deploying production clouds, we recommend backing glance with a swift backend or some form of shared storage.

Configuring default and additional stores

OpenStack-Ansible provides two configurations for controlling where glance stores files: the default store and additional stores. glance stores images in file-based storage by default. Two additional stores, http and cinder (Block Storage), are also enabled by default.

You can choose alternative default stores and alternative additional stores. For example, a deployer that uses Ceph can configure the following Ansible variables:

glance_default_store = rbd
glance_additional_stores:
  - swift
  - http
  - cinder

The configuration above configures glance to use rbd (Ceph) by default, but glance_additional_stores list enables swift, http and cinder stores in the glance configuration files.

The following example sets glance to use the images pool. This example uses cephx authentication and requires an existing glance account for the images pool.

In user_variables.yml:

glance_default_store: rbd
ceph_mons:
  - 172.29.244.151
  - 172.29.244.152
  - 172.29.244.153

You can use the following variables if you are not using the defaults:

glance_ceph_client: <glance-username>
glance_rbd_store_pool: <glance-pool-name>
glance_rbd_store_chunk_size: <chunk-size>

Storing images in Cloud Files

The following procedure describes how to modify the /etc/openstack_deploy/user_variables.yml file to enable Cloud Files usage.

  1. Change the default store to use Object Storage (swift), the underlying architecture of Cloud Files:

    glance_default_store: swift
    
  2. Set the appropriate authentication URL and version:

    glance_swift_store_auth_version: 2
    glance_swift_store_auth_address: https://127.0.0.1/v2.0
    
  3. Set the swift account credentials:

    # Replace this capitalized variables with actual data.
    glance_swift_store_user: GLANCE_SWIFT_TENANT:GLANCE_SWIFT_USER
    glance_swift_store_key: SWIFT_PASSWORD_OR_KEY
    
  4. Change the glance_swift_store_endpoint_type from the default internalURL settings to publicURL if needed.

    glance_swift_store_endpoint_type: publicURL
    
  5. Define the store name:

    glance_swift_store_container: STORE_NAME
    

    Replace STORE_NAME with the container name in swift to be used for storing images. If the container does not exist, it is automatically created.

  6. Define the store region:

    glance_swift_store_region: STORE_REGION
    

    Replace STORE_REGION if needed.

  7. (Optional) Set the paste deploy flavor:

    glance_flavor: GLANCE_FLAVOR
    

    By default, glance uses caching and authenticates with the Identity (keystone) service. The default maximum size of the image cache is 10GB. The default glance container size is 12GB. In some configurations, glance attempts to cache an image which exceeds the available disk space. If necessary, you can disable caching. For example, to use Identity without caching, replace GLANCE_FLAVOR with keystone:

    glance_flavor: keystone
    

    Or, to disable both authentication and caching, set GLANCE_FLAVOR to no value:

    glance_flavor:
    

    This option is set by default to use authentication and cache management in the playbooks/roles/os_glance/defaults/main.yml file. To override the default behavior, set glance_flavor to a different value in /etc/openstack_deploy/user_variables.yml.

    The possible values for GLANCE_FLAVOR are:

    • (Nothing)

    • caching

    • cachemanagement

    • keystone

    • keystone+caching

    • keystone+cachemanagement (default)

    • trusted-auth

    • trusted-auth+cachemanagement

Special considerations

If the swift password or key contains a dollar sign ($), it must be escaped with an additional dollar sign ($$). For example, a password of super$ecure would need to be entered as super$$ecure. This is necessary due to the way oslo.config formats strings.

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