def get_connection(read_only=False):
"""
Returns an object representing the connection to a virtualization
platform.
This could be :mod:`engine.virt.fake.FakeConnection` in test mode,
a connection to KVM, QEMU, or UML via :mod:`libvirt_conn`, or a connection
to XenServer or Xen Cloud Platform via :mod:`xenapi`.
Any object returned here must conform to the interface documented by
:mod:`FakeConnection`.
**Related flags**
:connection_type: A string literal that falls through a if/elif structure
to determine what virtualization mechanism to use.
Values may be
* fake
* libvirt
* xenapi
"""
# TODO(termie): maybe lazy load after initial check for permissions
# TODO(termie): check whether we can be disconnected
t = FLAGS.connection_type
if t == 'fake':
conn = fake.get_connection(read_only)
elif t == 'libvirt':
conn = libvirt_conn.get_connection(read_only)
elif t == 'xenapi':
conn = xenapi_conn.get_connection(read_only)
elif t == 'hyperv':
conn = hyperv.get_connection(read_only)
elif t == 'vmwareapi':
conn = vmwareapi_conn.get_connection(read_only)
else:
raise Exception('Unknown connection type "%s"' % t)
if conn is None:
LOG.error(_('Failed to open connection to the hypervisor'))
sys.exit(1)
return utils.check_isinstance(conn, driver.ComputeDriver)
def _map_to_instance_info(self, instance):
instance = utils.check_isinstance(instance, FakeInstance)
info = driver.InstanceInfo(instance.name, instance.state)
return info
