1c7f556d4f
This change moves existing files, updates a few of the cross-references and paths, and fixes some formatting. It is not meant to be the final word on how the main page looks or how the other files are organized, but it gets everything roughly into shape. If the glance team wants to make changes, please do those as follow-up patches This change depends on the spec and on a feature of pbr that allows us to move where the auto-generated class reference documentation ends up in the tree. Depends-On: Ia750cb049c0f53a234ea70ce1f2bbbb7a2aa9454 Depends-On: I2bd5652bb59cbd9c939931ba2e7db1b37d2b30bb Change-Id: I9dde267793a5913acb5b1ec028cfb66bc5189783 Signed-off-by: Doug Hellmann <doug@doughellmann.com>
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Glance database architecture
Glance Database Public API
The Glance Database API contains several methods for moving image metadata to and from persistent storage. You can find a list of public methods grouped by category below.
Common parameters for image methods
- The following parameters can be applied to all of the image methods below:
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context— corresponds to a glance.context.RequestContext object, which stores the information on how a user accesses the system, as well as additional request information.image_id— a string corresponding to the image identifier.memb_id— a string corresponding to the member identifier of the image.
Image basic methods
Image processing methods:
image_create(context, values)— creates a new image record with parameters listed in the values dictionary. Returns a dictionary representation of a newly created glance.db.sqlalchemy.models.Image object.image_update(context, image_id, values, purge_props=False, from_state=None)— updates the existing image with the identifier image_id with the values listed in the values dictionary. Returns a dictionary representation of the updated Image object.
- Optional parameters are:
purge_props— a flag indicating that all the existing properties not listed in the values['properties'] should be deleted;from_state— a string filter indicating that the updated image must be in the specified state.
image_destroy(context, image_id)— deletes all database records of an image with the identifier image_id (like tags, properties, and members) and sets a 'deleted' status on all the image locations.image_get(context, image_id, force_show_deleted=False)— gets an image with the identifier image_id and returns its dictionary representation. The parameter force_show_deleted is a flag that indicates to show image info even if it was 'deleted', or its 'pending_delete' statuses.image_get_all(context, filters=None, marker=None, limit=None, sort_key=None, sort_dir=None, member_status='accepted', is_public=None, admin_as_user=False, return_tag=False)— gets all the images that match zero or more filters.
- Optional parameters are:
filters— dictionary of filter keys and values. If a 'properties' key is present, it is treated as a dictionary of key/value filters in the attribute of the image properties.marker— image id after which a page should start.limit— maximum number of images to return.sort_key— list of image attributes by which results should be sorted.sort_dir— direction in which results should be sorted (asc, desc).member_status— only returns shared images that have this membership status.is_public— if true, returns only public images. If false, returns only private and shared images.admin_as_user— for backwards compatibility. If true, an admin sees the same set of images that would be seen by a regular user.return_tag— indicates whether an image entry in the result includes its relevant tag entries. This can improve upper-layer query performance and avoid using separate calls.
Image location methods
Image location processing methods:
image_location_add(context, image_id, location)— adds a new location to an image with the identifier image_id. This location contains values listed in the dictionary location.image_location_update(context, image_id, location)— updates an existing location with the identifier location['id'] for an image with the identifier image_id with values listed in the dictionary location.image_location_delete(context, image_id, location_id, status, delete_time=None)— sets a 'deleted' or 'pending_delete' status to an existing location record with the identifier location_id for an image with the identifier image_id.
Image property methods
Warning
There is no public property update method. So if you want to modify it, you have to delete it first and then create a new one.
Image property processing methods:
image_property_create(context, values)— creates a property record with parameters listed in the values dictionary for an image with values['id']. Returns a dictionary representation of a newly created ImageProperty object.image_property_delete(context, prop_ref, image_ref)— deletes an existing property record with a name prop_ref for an image with the identifier image_ref.
Image member methods
Methods to handle image memberships:
image_member_create(context, values)— creates a member record with properties listed in the values dictionary for an image with values['id']. Returns a dictionary representation of a newly created ImageMember object.image_member_update(context, memb_id, values)— updates an existing member record with properties listed in the values dictionary for an image with values['id']. Returns a dictionary representation of an updated member record.image_member_delete(context, memb_id)— deletes an existing member record with memb_id.image_member_find(context, image_id=None, member=None, status=None)— returns all members for a given context with optional image identifier (image_id), member name (member), and member status (status) parameters.image_member_count(context, image_id)— returns a number of image members for an image with image_id.
Image tag methods
Methods to process images tags:
image_tag_set_all(context, image_id, tags)— changes all the existing tags for an image with image_id to the tags listed in the tags param. To remove all tags, a user just should provide an empty list.image_tag_create(context, image_id, value)— adds a value to tags for an image with image_id. Returns the value of a newly created tag.image_tag_delete(context, image_id, value)— removes a value from tags for an image with image_id.image_tag_get_all(context, image_id)— returns a list of tags for a specific image.
Image info methods
The next two methods inform a user about his or her ability to modify and view an image. The image parameter here is a dictionary representation of an Image object.
is_image_mutable(context, image)— informs a user about the possibility to modify an image with the given context. Returns True if the image is mutable in this context.is_image_visible(context, image, status=None)— informs about the possibility to see the image details with the given context and optionally with a status. Returns True if the image is visible in this context.
Glance database schema
Image 1. Glance images DB schema
Glance Database Backends
Migration Backends
glance.database.migration_backend
Metadata Backends
glance.database.metadata_backend