[RFE] Share capabilities are missing from share instance model

[Goutham Pacha Ravi]

Share has new keys for share capabilities that affect APIs: snapshot_support, create_share_from_snapshot_support, replication_type, mount_snapshot_support, revert_to_snapshot_support.

Only replication_type is present in the share instance object sent down to the driver, even if we assume that the share instance has all of the share data set in it.

More info on this bug (19/03/2020)
There are things we know that are in the share model that can help drivers when acting on any share but, we don't pass them down... drivers are already written in a way to call back into the database and retrieve the share type. So, if we make this change, in theory drivers can avoid that call - however, driver authors may still not have everything they need.
Adding this params would avoid an unnecessary round trip to the database from within a share driver.

[Jason Grosso (jgrosso)]

Hey Goutham any update on this one ?

[Vida Haririan (vhariria)]

Additional comments http://eavesdrop.openstack.org/meetings/manila/2020/manila.2020-03-19-15.00.log.html

[Vida Haririan (vhariria)]

Discussed this bug in detail, see comments here: https://meetings.opendev.org/meetings/manila/2021/manila.2021-10-14-15.01.log.html

[Goutham Pacha Ravi (gouthamr)]

As the IRC discussion states, in all the driver calls in share/manager.py, the share manager passes the share (instance) model to the drivers - but, during provisioning (create, manage, create_from_snapshot, etc), drivers will need the extra-specs from the share type associated with the share instance to perform some actions.

So the solution to this RFE can be in several parts:

1) Grab the extra-specs from the share instance's share type and pass it down to the drivers in the share object as share['capabilities']. This method can be used to serialize the share instance: https://opendev.org/openstack/manila/src/commit/34d209484366cd921e052d37c5f9daef5e97af20/manila/share/manager.py#L4746-L4790 so that its not a sqlalchemy model object.

2) Drivers that currently query the share type extra specs for provisioning can stop doing so and rely on the share['capabilities']

Part (2) can be completed in separate follow up patches.

Since this is a good opportunity for new contributors to learn this part of the codebase, i'm tagging this as a "low-hanging-fruit".

Please feel free to claim this bug and work with any of the maintainers to fix it.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/c/openstack/manila/+/840187

[Goutham Pacha Ravi (gouthamr)]

This bug was discussed at a team meeting: https://meetings.opendev.org/meetings/manila/2023/manila.2023-11-09-15.01.log.html#l-75

[Goutham Pacha Ravi (gouthamr)]

@msaravan: Please feel free to assign this to someone else on your team...