--hard must be explicitly enbled

doc/topics/map.rst

@@ -47,6 +47,14 @@ that exist but are not specified in the map file will be destroyed:
 
     $ salt-cloud -m /path/to/mapfile -P -H
 
+Be careful with this argument, it is very dangerous! In fact, it is so
+dangerous that in order to use it, you must explicitly enable it in the main
+configuration file.
+
+.. code-block:: yaml
+
+    enable_hard_maps: True
+
 A map file can include grains:
 
 .. code-block:: yaml

saltcloud/cloud.py

@@ -4,6 +4,7 @@ correct cloud modules
 '''
 # Import python libs
 import os
+import sys
 import copy
 import multiprocessing
 import logging
@@ -399,8 +400,15 @@ class Map(Cloud):
                     if prov != 'aws' or pmap['aws'][name]['state'] != 2:
                         ret['create'].pop(name)
         if self.opts['hard']:
+            if self.opts['enable_hard_maps'] is True:
                 # Look for the items to delete
                 ret['destroy'] = exist.difference(defined)
+            else:
+                print('The --hard map can be extremely dangerous to use, and '
+                      'therefore must explicitly be enabled in the main'
+                      'configuration file, by setting enable_hard_maps to '
+                      'True')
+                sys.exit(1)
         return ret
 
     def run_map(self, dmap):