remove tags by key only

ec2_tag

+++ b/lib/ansible/modules/cloud/amazon/ec2_tag.py
@@ -33,6 +33,10 @@ options:
     default: present
     choices: ['present', 'absent', 'list']
     aliases: []
+  remove_by_tag_key_only:
+    description:
+      - a boolean to indicate whether to remove tags with matching keys
+    default: False
   tags:
     description:
       - a hash/dictionary of tags to add to the resource; '{"key":"value"}' and '{"key":"value","key":"value"}'
@@ -129,6 +133,7 @@ def main():
         resource = dict(required=True),
         tags = dict(type='dict'),
         state = dict(default='present', choices=['present', 'absent', 'list']),
+        remove_by_tag_key_only = dict(default=False, type='bool'),
     )
     )
     module = AnsibleModule(argument_spec=argument_spec, supports_check_mode=True)
@@ -139,6 +144,7 @@ def main():
     resource = module.params.get('resource')
     tags = module.params.get('tags')
     state = module.params.get('state')
+    remove_by_tag_key_only = module.params.get('remove_by_tag_key_only')

     ec2 = ec2_connect(module)

@@ -170,14 +176,23 @@ def main():
     if state == 'absent':
         if not tags:
             module.fail_json(msg="tags argument is required when state is absent")
-        for (key, value) in set(tags.items()):
-            if (key, value) not in set(tagdict.items()):
-                baddict[key] = value
-                if set(baddict) == set(tags):
-                    module.exit_json(msg="Nothing to remove here. Move along.", changed=False)
-        for (key, value) in set(tags.items()):
-            if (key, value) in set(tagdict.items()):
-                dictremove[key] = value
+        if remove_by_tag_key_only:
+            for (key, value) in set(tagdict.items()):
+                if key not in tags:
+                    baddict[key] = value
+                if set(baddict.keys()) == set(tags.keys()):
+                    module.exit_json(msg="Nothing to remove here.", changed=False)
+                if key in tags:
+                    dictremove[key] = value
+        else:
+            for (key, value) in set(tags.items()):
+                if (key, value) not in set(tagdict.items()):
+                    baddict[key] = value
+                    if set(baddict) == set(tags):
+                        module.exit_json(msg="Nothing to remove here. Move along.", changed=False)
+            for (key, value) in set(tags.items()):
+                if (key, value) in set(tagdict.items()):
+                    dictremove[key] = value