don't migrate; use template subdir

playbooks/edx-west/carnegie-prod-app.yml

+# we never want to migrate from these machines, so note no vars_prompt
+# section like other appservers
 
-# set up the fireball transport
-#- hosts: ~tag_Name_app(10|20)_cme
-#  gather_facts: no
-#  connection: ssh # or paramiko
-#  sudo: yes
-#  tasks:
-#      - apt: pkg=gcc state=present
-#      - apt: pkg=libzmq-dev,python-zmq state=present
-#      - action: fireball
-
-
-# this gets all running prod webservers
-#- hosts: tag_environment_prod:&tag_function_webserver
-# or we can get subsets of them by name
 - hosts: ~tag_Name_app(10|20)_carn
   sudo: True
-  vars_prompt:
-    - name: "migrate_db"
-      prompt: "Should this playbook run database migrations? (Type 'yes' to run, anything else to skip migrations)"
-      default: "no"
-      private: no
   vars:
     secure_dir: '../../../edx-secret/ansible'
     # this indicates the path to site-specific (with precedence)
@@ -33,6 +16,6 @@
   roles:
     - common
     - nginx
-    - {'role': 'edxapp', 'openid_workaround': true}
+    - {'role': 'edxapp', 'openid_workaround': true, 'template_subdir': 'carnegie'}
     # run this role last
     # - in_production