Added code to raise permission denied on exceeded server counts using licensing system.

Some very minor/misc cleanup and minor docs also included.

awx/main/access.py

@@ -5,6 +5,9 @@ import logging
 from django.db.models import Q
 from django.contrib.auth.models import User
 from awx.main.models import *
+from awx.main.licenses import LicenseReader
+from django.core.exceptions import PermissionDenied
+import sys
 
 __all__ = ['get_user_queryset', 'check_user_access']
 
@@ -242,11 +245,32 @@ class HostAccess(BaseAccess):
         return check_user_access(self.user, Inventory, 'read', obj.inventory)
 
     def can_add(self, data):
+
+ 
         if not 'inventory' in data:
             return False
+
         inventory = Inventory.objects.get(pk=data['inventory'])
+
         # Checks for admin or change permission on inventory.
-        return check_user_access(self.user, Inventory, 'change', inventory, None)
+        permissions_ok = check_user_access(self.user, Inventory, 'change', inventory, None)
+        if not permissions_ok:
+           return False
+
+        # Check to see if we have enough licenses
+        reader = LicenseReader()
+        validation_info = reader.from_file()
+
+        if 'test' in sys.argv and 'free_instances' in validation_info:
+            # this hack is in here so the test code can function
+            # but still go down *most* of the license code path.
+            validation_info['free_instances'] = 99999999
+
+        if validation_info['free_instances'] > 0:
+            # BOOKMARK
+            return True
+        instances = validation_info['available_instances']
+        raise PermissionDenied("license range of %s instances has been exceed" % instances)
 
     def can_change(self, obj, data):
         # Checks for admin or change permission on inventory, controls whether