hub: new listCGs RPC

Add a new hub method for listing new content generator records.

The purpose of this change is to make it easier for administrators to
determine what content generators are present and what user accounts
have access to those.

hub/kojihub.py

@@ -8060,6 +8060,35 @@ def set_user_status(user, status):
         raise koji.GenericError('invalid user ID: %i' % user_id)
 
 
+def list_cgs():
+    """List all available content generators in the system
+
+    :returns: A map of content generators, like {"name": data}. The data map
+              for each content generator has an "id" key for the content
+              generator ID, and a "users" key for the a list usernames who
+              are permitted to import for this content generator.
+    """
+
+    fields = {'content_generator.id': 'id', 'content_generator.name': 'name',
+              'users.name': 'user_name'}
+    columns, aliases = zip(*fields.items())
+    tables = ['cg_users']
+    joins = ['content_generator ON content_generator.id = cg_users.cg_id',
+             'users ON users.id = cg_users.user_id']
+    clauses = ['cg_users.active = TRUE']
+    query = QueryProcessor(tables=tables, aliases=aliases, columns=columns,
+                           joins=joins, clauses=clauses)
+    cgs = {}
+    for result in query.iterate():
+        cg_id = result['id']
+        cg_name = result['name']
+        user_name = result['user_name']
+        if cg_name not in cgs:
+            cgs[cg_name] = {'id': cg_id, 'users': []}
+        cgs[cg_name]['users'].append(user_name)
+    return cgs
+
+
 def grant_cg_access(user, cg, create=False):
     """
     Grant user access to act as the given content generator
@@ -11068,6 +11097,7 @@ class RootExports(object):
             raise koji.GenericError('unknown user: %s' % username)
         set_user_status(user, koji.USER_STATUS['BLOCKED'])
 
+    listCGs = staticmethod(list_cgs)
     grantCGAccess = staticmethod(grant_cg_access)
     revokeCGAccess = staticmethod(revoke_cg_access)