Tutorial

This tutorial is intended as an introduction to working with os-brick.

Prerequisites

Before we start, make sure that you have the os-brick distribution installed. In the Python shell, the following should run without raising an exception:

>>> import os_brick

Configuration

There are some os-brick connectors that use file locks to prevent concurrent access to critical sections of the code.

These file locks use the oslo.concurrency lock_utils module and require the lock_path to be configured with the path where locks should be created.

os-brick can use a specific directory just for its locks or use the same directory as the service using os-brick.

The os-brick specific configuration option is [os_brick]/lock_path, and if left undefined it will use the value from [oslo_concurrency]/lock_path.

Setup

Once os_brick has been loaded it needs to be initialized, which is done by calling the os_brick.setup method with the oslo.conf configuration.

It is important that the call to setup method happens after oslo.config has been properly initialized.

from oslo_config import cfg
from cinder import version

CONF = cfg.CONF

def main():
    CONF(sys.argv[1:], project='cinder',
         version=version.version_string())
    os_brick.setup(CONF)

Fetch all of the initiator information from the host

An example of how to collect the initiator information that is needed to export a volume to this host.

from os_brick.initiator import connector


os_brick.setup(CONF)

# what helper do you want to use to get root access?
root_helper = "sudo"
# The ip address of the host you are running on
my_ip = "192.168.1.1"
# Do you want to support multipath connections?
multipath = True
# Do you want to enforce that multipath daemon is running?
enforce_multipath = False
initiator = connector.get_connector_properties(root_helper, my_ip,
                                               multipath,
                                               enforce_multipath)