OPS-2492 Support redis as an ecommerce celery backend in edx/configuration Ansible

CHANGELOG.md

+- Role: ecommerce
+  - Added `ECOMMERCE_CELERY_BROKER_TRANSPORT` and renamed `ECOMMERCE_BROKER_HOST`
+    to `ECOMMERCE_CELERY_BROKER_HOSTNAME`. This is to support non-amqp brokers,
+    specifically redis. If `ECOMMERCE_CELERY_BROKER_HOSTNAME` is unset it will use
+    the value of `ECOMMERCE_BROKER_HOST`, however it is recommended to update
+    your configuration to set `ECOMMERCE_CELERY_BROKER_HOSTNAME` explicitly.
+
 - Role: credentials
   - This role is now dependent on the edx_django_service role. Settings are all the same, but nearly all of the tasks are performed by the edx_django_service role.
 

playbooks/roles/ecommerce/defaults/main.yml

@@ -145,11 +145,11 @@ ECOMMERCE_STATICFILES_STORAGE: 'ecommerce.theming.storage.ThemeStorage'
 # Celery
 ECOMMERCE_BROKER_USERNAME: 'celery'
 ECOMMERCE_BROKER_PASSWORD: 'celery'
-# Used as the default RabbitMQ IP.
 ECOMMERCE_BROKER_HOST: '{{ ansible_default_ipv4.address }}'
-# Used as the default RabbitMQ port.
 ECOMMERCE_BROKER_PORT: 5672
-ECOMMERCE_BROKER_URL: 'amqp://{{ ECOMMERCE_BROKER_USERNAME }}:{{ ECOMMERCE_BROKER_PASSWORD }}@{{ ECOMMERCE_BROKER_HOST }}:{{ ECOMMERCE_BROKER_PORT }}'
+ECOMMERCE_CELERY_BROKER_TRANSPORT: 'amqp'
+ECOMMERCE_CELERY_BROKER_HOSTNAME: '{{ ECOMMERCE_BROKER_HOST }}'
+ECOMMERCE_BROKER_URL: '{{ ECOMMERCE_CELERY_BROKER_TRANSPORT }}://{{ ECOMMERCE_BROKER_USERNAME }}:{{ ECOMMERCE_BROKER_PASSWORD }}@{{ ECOMMERCE_CELERY_BROKER_HOSTNAME }}:{{ ECOMMERCE_BROKER_PORT }}'
 
 ECOMMERCE_DISCOVERY_SERVICE_URL: 'http://localhost:8008'
 ECOMMERCE_ENTERPRISE_URL: '{{ ECOMMERCE_LMS_URL_ROOT }}'