make - replacement in group names optional

contrib/inventory/ec2.ini

@@ -94,6 +94,9 @@ cache_max_age = 300
 # Organize groups into a nested/hierarchy instead of a flat namespace.
 nested_groups = False
 
+# Replace - tags when creating groups to avoid issues with ansible
+replace_dash_in_groups = True
+
 # The EC2 inventory output can become very large. To manage its size,
 # configure which groups should be created.
 group_by_instance_id = True

contrib/inventory/ec2.py

@@ -327,6 +327,12 @@ class Ec2Inventory(object):
         else:
             self.nested_groups = False
 
+        # Replace dash or not in group names
+        if config.has_option('ec2', 'replace_dash_in_groups'):
+            self.replace_dash_in_groups = config.getboolean('ec2', 'replace_dash_in_groups')
+        else:
+            self.replace_dash_in_groups = True
+
         # Configure which groups should be created.
         group_by_options = [
             'group_by_instance_id',
@@ -1285,10 +1291,11 @@ class Ec2Inventory(object):
         return re.sub('([a-z0-9])([A-Z])', r'\1_\2', temp).lower()
 
     def to_safe(self, word):
-        ''' Converts 'bad' characters in a string to underscores so they can be
-        used as Ansible groups '''
-
-        return re.sub("[^A-Za-z0-9\_]", "_", word)
+        ''' Converts 'bad' characters in a string to underscores so they can be used as Ansible groups '''
+        regex = "[^A-Za-z0-9\_"
+        if self.replace_dash_in_groups:
+            regex += "\-"
+        return re.sub(regex + "]", "_", word)
 
     def json_format_dict(self, data, pretty=False):
         ''' Converts a dict to a JSON object and dumps it as a formatted