Index: trunk/packages/invirt-base/python/invirt/authz.py
===================================================================
--- trunk/packages/invirt-base/python/invirt/authz.py	(revision 2989)
+++ trunk/packages/invirt-base/python/invirt/authz.py	(revision 2989)
@@ -0,0 +1,31 @@
+"""Invirt authorization.
+
+This module acts as a loader for the pluggable authorization system.
+
+Any Python module which wishes to provide an authorization scheme for
+Invirt should advertise an entry point in the invirt.authz group with
+a unique name. That name can then be configured in
+/etc/invirt/master.yaml as the authz mechanism.
+"""
+
+
+import pkg_resources
+
+from invirt.config import structs as cfg
+
+
+def expandOwner(name):
+    """Expand an "owner" to a list of authorized users."""
+    for ep in pkg_resources.iter_entry_points('invirt.authz', cfg.authz.name):
+        return ep.load().expandOwner(name)
+
+
+def expandAdmin(name):
+    """Expand an "administrator" to a list of authorized users."""
+    for ep in pkg_resources.iter_entry_points('invirt.authz', cfg.authz.name):
+        return ep.load().expandAdmin(name)
+
+
+__all__ = ['expandOwner',
+           'expandAdmin',
+           ]