allow ini file setting via environment variable

playbooks/ec2.py

@@ -222,7 +222,10 @@ class Ec2Inventory(object):
                            help='Get all the variables about a specific instance')
         parser.add_argument('--refresh-cache', action='store_true', default=False,
                            help='Force refresh of cache by making API requests to EC2 (default: False - use cache files)')
-        parser.add_argument('--inifile', dest='inifile', help='Path to init script to use', default=os.path.dirname(os.path.realpath(__file__))+'/ec2.ini',)
+        
+        default_inifile = os.environ.get("ANSIBLE_EC2_INI", os.path.dirname(os.path.realpath(__file__))+'/ec2.ini')
+
+        parser.add_argument('--inifile', dest='inifile', help='Path to init script to use', default=default_inifile)
         self.args = parser.parse_args()