Redis connect to cloud.gov backend service

This is a demo application that shows how to use Redis pub/sub to securely connect a frontend application to a backend service using a brokered instance of AWS Elasticache.

In the example, the backend application simply echos back a message sent by the front end, but this approach could support much more complex backend functions if needed.

Benefits:

• Traffic between a frontend application and a backend service running on a separate container are fully encrypted.
• No need to create or manage network policies. All communications between the frontend and backend app happens through Redis.

Drawbacks:

• This approach to breaking out services might not be a good fit for all scenarios.
• If/when traffic between containers in Cloud Foundry is encrypted natively, this approach might add unneeded complexity.
• Additional logic to manage or restore connections to Redis would likely be needed if this approach were to be used for a production application.
• Potential for latency to be introduced as traffic goes to AWS between frontend and backend apps.

Instructions

• Set up a new AWS Elasticache service: cf create-service aws-elasticache-redis redis-dev {service-name} (note - this may take several minutes to finish). Use the service-name in the next two steps.
• in the /backend directory, change the route and the service-name in the manifest.yml file. The route should use the apps.internal domain as we do not want this app to be accessible externally or from other app containers.
• cf push from the /backend directory.
• In the /frontend directory change the service-name in the manifest.yml file
• cf push from the /frontend directory.

Make a curl request to the front-end app like this:

~$ curl -X POST https://frontend-app-happy-duiker-vz.app.cloud.gov/ -d '{"message":"cloud.gov is really awesome"}' -H 'Content-type:application/json

You should see a response like this:

Backend app says: Received "cloud.gov is really awesome" from the front end app on "from-frontend" channel