email-sender-compose is a complete example of an application with multiples services in docker. This application has some nice components:

• Web Server: Configured with nginx to provide pages and to create a layer that directs clients' requests to the appropriate backend server (reverse proxy).
• Database: Postgres - used just to store simple messages.
• Workers: Used for capture messages from service queue and send them.
• Queue management: With redis it was possible to create a queue service that provides messages to workers.
• Main application: It's a little backend server that communicates with database service and sends messages to queue service.

Final Diagram

First of all, make sure you have installed docker and docker-compose on your machine.

After that, create a copy from file env.example and rename them to .env:

cp env.example .env

Obs: Just remember to define a value to DB_PASSWORD.

Finally, just build all containers and be happy!

sudo docker-compose up -d

We can run multiples instances of workers on demand for messaging. To define the numbers of workers use the following command:

sudo docker-compose up -d --scale worker=<number_of_instances>