Simple poll web application. Poll is a Python Flask web application that gathers the votes to push them into a Redis queue. The JavaWorker consumes the votes stored in the Redis queue, then pushes it into a PostgreSQL database. Finally, the Node.js Result web application fetches the votes from the DB and displays the result.

5 services:

1. poll:
   • build your poll image and redirect port 5000 of the host to the port 80 of the image.
2. redis:
   • use an existing image of redis and open port 6379
3. worker:
   • build your worker image.
4. db:
   • representing the database that will be used by the apps. You must use an existing image of postgres. Database schema must be created during container first start.
5. result:
   • build your result image and redirect port 5001 of the host to the port 80 of the image.

3 networks:

• poll-tier to allow poll to communicate with redis
• result-tier to allow result to communicate with db
• back-tier to allow worker to communicate with redis and db

1 volume:

• db-data will make the database data persistent, if the container dies.