Defaults EDXAPP_MONGO_HOSTS to a comma-separated string list

CHANGELOG.md

@@ -12,8 +12,6 @@
   - Added `EDXAPP_MONGO_REPLICA_SET`, which is required to use
     pymongo.MongoReplicaSetClient in PyMongo 2.9.1.  This should be set to the
     name of your replica set.
-    Note that setting `EDXAPP_MONGO_REPLICA_SET` requires `EDXAPP_MONGO_HOSTS`
-    to be a comma-delimited string listing the host names, not an array.
     This setting causes the `EDXAPP_*_READ_PREFERENCE` settings below to be used.
   - Added `EDXAPP_MONGO_CMS_READ_PREFERENCE` with a default value of `PRIMARY`.
   - Added `EDXAPP_MONGO_LMS_READ_PREFERENCE` with a default value of

playbooks/roles/edxapp/defaults/main.yml

@@ -65,9 +65,8 @@ EDXAPP_XQUEUE_DJANGO_AUTH:
   password: 'password'
 EDXAPP_XQUEUE_URL: 'http://localhost:18040'
 
-# EDXAPP_MONGO_HOSTS must be a comma seperated list of hosts/ips for
-# compatibility with pymongo.MongoReplicaSetClient in PyMongo 2.9.1
-EDXAPP_MONGO_HOSTS: ['localhost']
+# Comma-separated list of hosts/ips
+EDXAPP_MONGO_HOSTS: 'localhost'
 EDXAPP_MONGO_PASSWORD: 'password'
 EDXAPP_MONGO_PORT: 27017
 EDXAPP_MONGO_USER: 'edxapp'