Learn Microservice - Basic CQRS

Below concept are covered in this repository:

• API Gateway
• gRPC
• Basic CQRS pattern with rabbitMQ

Architecture

                          ||=========================||
                          ||     MySQL1(Write DB)    ||
                          ||=========================||
                                        ↑
                                        | Write
||==============|| gRPC   ||=========================|| pub [product_add] ||==========||
|| API Gateway  ||------->|| Product Command Service ||------------------>|| rabbitMQ ||
||==============||        ||=========================||                   ||==========||
        |                                                                       |
        |      gRPC       ||=========================||                         |
        ----------------> || Product Query Service   ||                         |
                          ||=========================||                         |
                                        ↑                                       |
                                        |                     sub [product_add] |          
                                        | Read                                  |
                                        |                       ||==========================||
                          ||=========================||         ||     Product Listener     ||
                          ||     MySQL2(Read DB)     ||<------- ||          Service         ||
                          ||=========================||   Write ||==========================||

Explanation

This example is consist of 2 API endpoint

• /product/add : when user hit add product endpoint, API gateway will reach product command service through gRPC. Product command service will insert new product data to mysql1 and publish product_add event to message broker. Product listener is already listen to product_add event, so it will consume product_add event and thus insert new product data in mysql2
• /product/search : API gateway will reach product query service through gRPC, product query service will directly read data from mysql2 and return search result to API gateway

Deployment

1. Using docker compose

docker-compose up --build

2. Open your browser and access http://localhost:3000/docs/