Table of Contents

• Intro
• Customers & Provider registering
• Orders -customers online shopping
• Products - inventory
• Customers & Provider API
• Orers API
• Kafka & docker
• nginx
• Redis

Ecosystem express

Demo of microservices ecosystem interconected interconnected with each other using DDD clean architecture and CQRS The transaction between microservices was solved using Event Soursing with kafka ....

pub_persons

This app is a cron-job typescript app service that will randomly generate fake customers and providers . 1- Generate ramdom persons 2- Performs calls to ComerceAPIExpress backend to get info from customers aand providers:

customer post to /api/customer/
provider post to /api/provider/

3- Every person and provider generaded will sended to ComerceAPIExpress for it creation (sql server ) api -> POST http://localhost:7000/api/persons/customers api -> POST http://localhost:7000/api/persons/providers

pub_product

This app is a cron-job typescript app service that will randomly generate & simulates products entering the shop werehause .-

This apps calls ComerceAPIExpress backend to creato or perfomr Inserts in the product storage (sql server ) api -> POST http://localhost:7000/api/products/

pub_orders

This app is a cron-job typescript app service that will randomly generate orders that simulates the customers online shopping .- To get porducts and customers for order creation this apps interacts with ComerceAPIExpress api -> GET http://localhost:7000/api/products/

This apps calls OrdersAPIExpress backend to create or perform Inserts in the orders storage (mongo)

ComerceAPIExpress

The comerce backend . It's an Express with typescript API that allows all CRUD operations for: customers providers and products

This api interact with sql server data and for each insert emit an event to the even-source. For this purpose we implement kafka api -> POST http://localhost:6001/api/orders/

OrdersAPIExpress

The Orders backend . It's an Express with typescript Express API that allows all CRUD operations for: orders This api interact with mongodb atlas server to store all orders and for each insert emit an event to the even-source. for this purpose we implement kafka

#Implent kafka as event sousing

Kafka docker images

Apache Kafka is a distributed streaming platform designed to build real-time pipelines and can be used as a message broker or as a replacement for a log aggregation solution for big data applications

We use Apache Kafka packaged by Bitnami

Run the application using Docker Compose

we use local docker-compose-kafka.yml content what should it contain this

    zookeeper:
        image: docker.io/bitnami/zookeeper:3.8
        ports:
        - "2181:2181"
        volumes:
        - "zookeeper_data:/bitnami"
        environment:
        - ALLOW_ANONYMOUS_LOGIN=yes
    kafka:
        image: docker.io/bitnami/kafka:3.2
        ports:
        - "9092:9092"
        volumes:
        - "kafka_data:/bitnami"
        environment:
        - KAFKA_CFG_ZOOKEEPER_CONNECT=zookeeper:2181
        - ALLOW_PLAINTEXT_LISTENER=yes
        depends_on:
        - zookeeper

Next run :

   docker-compose up -d
   docker-compose  -f docker-compose-kafka.yml up
   docker-compose  up docker-compose-kafka.yml -d

Below command will stop running containers, but it also removes the stopped containers as well as any networks that were created. And.. for to remove vulumes append -v flag

    docker-compose down
    or
    docker-compose down -v

kafka documentations

https://www.npmjs.com/package/kafkajs
https://www.youtube.com/watch?v=EiDLKECLcZw

kafka packages

yarn add kafkajs
this trow this error ✕ missing peer openapi-types@>=7...so you have to install

    pnpm openapi-types@>=7

yarn add @kafkajs/confluent-schema-registry

kafka packages

pnpm i kafkajs
this trow this error ✕ missing peer openapi-types@>=7...so you have to install

    pnpm openapi-types@>=7

yarn add i @kafkajs/confluent-schema-registry

nginx docker image

Run this commando to start up load balancer and reverse proxy for ours APIs

docker-compose up -d -f docker-compose-nginx.yml

If you open obove yml file you notice that we have several configurated things.

1- Load balancer for image moviedomfo/express_comerce (#ComerceAPIExpress) In docker compose we instantiate two containers for this api. One called ulises socrates and another ulises We configure this with back section -->

    upstream back
        server platon:INT_PORT;
        server hercules:INT_PORT;

Calls http://localhost:6001/api/persons/ can be redirected to either platon or hercules based on the upstream configuration

2- Reverse proxy for the previous services.

a-  location /platon/
    For calls http://localhost:6001/platon/api/persons/
b-   location /hercules/
For calls as http://localhost:6001/hercules/api/persons/

3 - Also, reverse porxy for moviedomfo/express_orders (#OrdersAPIExpress) dockers created in docker_file

a- location /ulises/ For calls http://localhost:6001/ulises/api/customers/ b- location /platon/ For calls as http://localhost:6001/platon/api/customers/

Redis docker image

For the purpose of implementing tokens-cache among other things, our ecosystem uses Redis Cache. To facilitate the container deployment, I have prepared a YAML file ready to run with Docker Hub.

Locate the directory where the "docker-compose-redis.yml" file is located. Root of all projects

    docker-compose -f docker-compose-redis.yml up -d