Expanding stores-info detail for other stores

https://blueprints.launchpad.net/glance/+spec/expanding-stores-detail

Problem description

In Yoga release we added a new API (GET /v2/info/stores/detail) which exposes the store specific details of a store. At the moment the Discovery API only exposes the store details and properties of the RBD backend. We want to make the API more generic and expose details of other stores also.

Proposed change

We will be extending the functionality of Discovery (GET /v2/info/stores/detail) API which will expose the store specific details about the store like store type and other specific store properties of other stores like cinder, swift, filesystem etc. Options that can be beneficial to be exposed for different stores :

• Cinder: cinder_volume_type

• Filesystem: filesystem_store_dir, chunk_size, thin_provisioning, filesystem_store_dirs

• Swift: container, obj_size and chunk_size

• S3: s3_store_large_object_size, s3_store_large_object_chunk_size, s3_store_thread_pools

We will use the existing method get_store_from_store_identifier which returns the store class instance and will utilize it to fetch the store specific information to return it via API.

Alternatives

None

Data model impact

None

REST API impact

With this new implementation, we will now be returning the “properties” value for other stores(apart from RBD).

GET /v2/info/stores/detail

The output will be as follows:

{
    "stores": [
        {
            "id":"reliable",
            "type": "rbd",
            "description": "Reliable RBD store",
            "default": true,
            "properties": {
                "pool": "pool1"
                "chunk_size": 65553
                "thin_provisioning": false
            }
        },
        {
            "id":"cheap",
            "type": "file",
            "description": "Cheap file store",
            "properties": {
                "datadir": "fdir"
                "chunk_size": 65553
                "thin_provisioning": false
            }
        },
        {
            "id":"fast",
            "type": "cinder",
            "description": "Fast Cinder Store",
            "properties": {
                "volume_type": "volume1"
                "use_multipath": false
            }
        },
        {
            "id":"slow",
            "type": "swift",
            "description": "Slow Swift store",
            "properties": {
                "container": "container1"
                "obj_size": 52428
                "chunk_size": 204800
            }
        },


    ]
}

Security impact

This API does expose some additional sensitive information, but only to admins, consistent with other things we already expose.

Notifications impact

None

Other end user impact

None

Performance Impact

None

Other deployer impact

None

Developer impact

None

Implementation

Assignee(s)

Primary assignee:

mrjoshi, whoami-rajat

Other contributors:

None

Work Items

• Fetch details from the specific store/backed and return it in the API response

Dependencies

None

Testing

• Unit Tests

• Functional Tests

Documentation Impact

Add documentation providing details about the properties exposed for each store

References

https://review.opendev.org/c/openstack/glance-specs/+/817391 https://review.opendev.org/c/openstack/glance/+/824438