Updated edxapp Elasticsearch config

The urllib3 library (used by the Elasticsearch Python library) expects ports to be integers, not strings, when passed as kwargs. Since Ansible and Jinja2 are not capable of rendering this value as a string, an alternate format of the config has been added.

playbooks/roles/edxapp/defaults/main.yml

@@ -97,14 +97,14 @@ EDXAPP_MYSQL_HOST: 'localhost'
 EDXAPP_MYSQL_PORT: '3306'
 
 EDXAPP_SEARCH_HOST: 'localhost'
-EDXAPP_SEARCH_PORT: '9200'
+EDXAPP_SEARCH_PORT: 9200
 
-# list of dictionaries of the format
-# { 'host': 'hostname', 'port': 'portnumber', 'otherconfigsuchas use_ssl': 'True' }
-# http://elasticsearch-py.readthedocs.org/en/master/api.html#elasticsearch
 EDXAPP_ELASTIC_SEARCH_CONFIG:
-  - host: "{{ EDXAPP_SEARCH_HOST }}"
-    port: "{{ EDXAPP_SEARCH_PORT }}"
+  # NOTE: We combine the host and port in this manner, as opposed to passing a dict with host and port keys, due to
+  # the fact that Ansible and Jinja2 will ultimately render the port as a string, which is unnacceptable by the
+  # consuming code. See http://elasticsearch-py.readthedocs.org/en/master/api.html#elasticsearch for alternative
+  # acceptable formats.
+  - "{{ EDXAPP_SEARCH_HOST }}:{{ EDXAPP_SEARCH_PORT }}"
 
 EDXAPP_SETTINGS: '{{ COMMON_EDXAPP_SETTINGS }}'