def _create_extension_manager(namespace):
"""Create the resource specific ExtensionManager instance.
Use stevedore to find all vendor extensions of resource from their
namespace and return the ExtensionManager instance.
:param namespace: The namespace for the entry points. It maps to a
specific Sushy resource type.
:returns: the ExtensionManager instance
:raises ExtensionError: on resource OEM extension load error.
"""
# namespace format is:
# ``sushy.resources.<underscore_joined_resource_name>.oems``
resource_name = namespace.split('.')[-2]
extension_manager = (stevedore.ExtensionManager(
namespace=namespace,
propagate_map_exceptions=True,
on_load_failure_callback=_raise))
LOG.debug(
'Resource OEM extensions for "%(resource)s" under namespace '
'"%(namespace)s":', {
'resource': resource_name,
'namespace': namespace
})
for extension in extension_manager:
LOG.debug('Found vendor: %(name)s target: %(target)s', {
'name': extension.name,
'target': extension.entry_point_target
})
if not extension_manager.names():
m = (('No extensions found for "%(resource)s" under namespace '
'"%(namespace)s"') % {
'resource': resource_name,
'namespace': namespace
})
LOG.error(m)
raise exceptions.ExtensionError(error=m)
return extension_manager
def _raise(m, ep, e):
raise exceptions.ExtensionError(
error='Failed to load entry point target: %(error)s' % {'error': e})