Add an expand_csv_tags setting to ec2.ini

If enabled, this will convert tags of the form "a,b,c" to a list and use
the results to create additional inventory groups.

This is based on PR #8676 by nickpeck (but not a straight rebase—both
the code and the nomenclature have been changed here).

Closes #8676

contrib/inventory/ec2.ini

@@ -97,6 +97,10 @@ nested_groups = False
 # Replace - tags when creating groups to avoid issues with ansible
 replace_dash_in_groups = True
 
+# If set to true, any tag of the form "a,b,c" is expanded into a list
+# and the results are used to create additional tag_* inventory groups.
+expand_csv_tags = False
+
 # 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

@@ -141,6 +141,7 @@ except ImportError:
 
 
 class Ec2Inventory(object):
+
     def _empty_inventory(self):
         return {"_meta" : {"hostvars" : {}}}
 
@@ -321,6 +322,11 @@ class Ec2Inventory(object):
         self.cache_path_index = cache_dir + "/ansible-ec2.index"
         self.cache_max_age = config.getint('ec2', 'cache_max_age')
 
+        if config.has_option('ec2', 'expand_csv_tags'):
+            self.expand_csv_tags = config.getboolean('ec2', 'expand_csv_tags')
+        else:
+            self.expand_csv_tags = False
+
         # Configure nested groups instead of flat namespace.
         if config.has_option('ec2', 'nested_groups'):
             self.nested_groups = config.getboolean('ec2', 'nested_groups')
@@ -696,6 +702,12 @@ class Ec2Inventory(object):
         # Inventory: Group by tag keys
         if self.group_by_tag_keys:
             for k, v in instance.tags.items():
+                if self.expand_csv_tags and v and ',' in v:
+                    values = map(lambda x: x.strip(), v.split(','))
+                else:
+                    values = [v]
+
+                for v in values:
                     if v:
                         key = self.to_safe("tag_" + k + "=" + v)
                     else:
@@ -1120,6 +1132,8 @@ class Ec2Inventory(object):
                 instance_vars['ec2_placement'] = value.zone
             elif key == 'ec2_tags':
                 for k, v in value.items():
+                    if self.expand_csv_tags and ',' in v:
+                        v = map(lambda x: x.strip(), v.split(','))
                     key = self.to_safe('ec2_tag_' + k)
                     instance_vars[key] = v
             elif key == 'ec2_groups':