cinder-specs/specs/liberty/valid-states-api.rst

Valid States API

Include the URL of your launchpad blueprint:

https://blueprints.launchpad.net/cinder/+spec/valid-states-api

Provide an API to obtain the set of valid states that are permissible to be used in the function to reset the state of a volume and snapshot.

Problem description

The purpose of this feature is to facilite exposing the reset-state API in horizon in a meaningful way by restricting the set of permissible states that the administrator can specify for a volume. There is no API for this, and it is undesirable to hardcode this information into horizon.

Use Cases

Proposed change

A new API function and corresponding cinder command will be added to determine the set of valid states for volumes or snapshots.

The initial proposal is to create a single function, get_valid_states, to obtain the valid states for any type of resource (volume, snapshot).

Alternatives

For consistency with the rest of cinder, get_valid_states may be renamed and/or split into multiple functions, one per resource type; this decision will be left as an implementation detail and will be finalized as part of the normal code review process.

Data model impact

None

REST API impact

Add a new REST API to retrieve valid states:

• GET /v2/{tenant_id}/states

JSON response schema definition:

'valid_states': {
    'type': 'array',
    'items' : {
        'type': 'string'
    }
}

Security impact

None

Notifications impact

None

Other end user impact

A new command, get-valid-states, will be added to python-cinderclient. This command mirrors the underlying API function.

Obtaining the list of valid states for a volume or snapshot can be performed by: $ cinder get-valid-states

Performance Impact

None

Other deployer impact

None

Developer impact

None

Implementation

Assignee(s)

Primary assignee:

thingee

Work Items

• Implement REST API
• Implement cinder client functions
• Implement cinder command

Dependencies

Horizon blueprints that will depend on this one:

• https://blueprints.launchpad.net/horizon/+spec/cinder-reset-volume-state
• https://blueprints.launchpad.net/horizon/+spec/cinder-reset-snapshot-state

Testing

None

Documentation Impact

The cinder client documentation will need to be updated to reflect the new command.

The cinder API documentation will need to be updated to reflect the REST API changes.

References

None