A microservice approach with C programming language

Here you can find a neat example of a microservices' architecture with C programming language.

Also following libraries are used:

1. ZeroMQ
2. Json Parser
3. PostgreSQL
4. Flask

Microservices

The solution comprises two services:

• API
• Transaction Service

API

The API is just a simple Flask server which is listening on default port 5000. It's designated to hand over a POST request from client to the ZeroMQ server on port 5555. On the other side of the ZeroMQ channel it's the transaction service, which is written in C programming language, listening for coming messages.

Transaction Service

The transaction service making a connection to PostgreSQL server, in this case test database. Transaction service is receiving a message from ZeroMQ and then commence a transactional query on the account table of test database. If user doesn't own sufficient fund the transaction will rollback.

How to run

Rename .env.example to .env then run

docker-compose up

and then send a request with enum direction{in,out}

curl -X POST localhost:5000 -d '{"user":"3","amount":"10","direction":"out"}'