Welcome to Cinder Library’s documentation!¶
The Cinder Library, also known as cinderlib, is a Python library that leverages the Cinder project to provide an object oriented abstraction around Cinder’s storage drivers to allow their usage directly without running any of the Cinder services or surrounding services, such as KeyStone, MySQL or RabbitMQ.
The library is intended for developers who only need the basic CRUD functionality of the drivers and don’t care for all the additional features Cinder provides such as quotas, replication, multi-tenancy, migrations, retyping, scheduling, backups, authorization, authentication, REST API, etc.
The library was originally created as an external project, so it didn’t have the broad range of backend testing Cinder does, and only a limited number of drivers were validated at the time. Drivers should work out of the box, and we’ll keep a list of drivers that have added the cinderlib functional tests to the driver gates confirming they work and ensuring they will keep working.
Features¶
Use a Cinder driver without running a DBMS, Message broker, or Cinder service.
Using multiple simultaneous drivers on the same application.
Basic operations support:
Create volume
Delete volume
Extend volume
Clone volume
Create snapshot
Delete snapshot
Create volume from snapshot
Connect volume
Disconnect volume
Local attach
Local detach
Validate connector
Extra Specs for specific backend functionality.
Backend QoS
Multi-pool support
Metadata persistence plugins:
Stateless: Caller stores JSON serialization.
Database: Metadata is stored in a database: MySQL, PostgreSQL, SQLite…
Custom plugin: Caller provides module to store Metadata and cinderlib calls it when necessary.
Example¶
The following code extract is a simple example to illustrate how cinderlib works. The code will use the LVM backend to create a volume, attach it to the local host via iSCSI, and finally snapshot it:
import cinderlib as cl
# Initialize the LVM driver
lvm = cl.Backend(volume_driver='cinder.volume.drivers.lvm.LVMVolumeDriver',
volume_group='cinder-volumes',
target_protocol='iscsi',
target_helper='lioadm',
volume_backend_name='lvm_iscsi')
# Create a 1GB volume
vol = lvm.create_volume(1, name='lvm-vol')
# Export, initialize, and do a local attach of the volume
attach = vol.attach()
print('Volume %s attached to %s' % (vol.id, attach.path))
# Snapshot it
snap = vol.create_snapshot('lvm-snap')
