API Eventos

Introduction

This API is responsible to provide a RESTFUL interface to do a facade between a broker and the producers. For this example, we will use as broker Kafka and we use Golang as a programming language.

Features

• One endpoint http://localhost:7777/events/ with the GET verb
• One endpoint http://localhost:7777/events/ with the POST verb
• One endpoint http://localhost:7777/topics with the POST verb
• A service with the main responsability of write a event on Kafka topic

Tech

API Eventos uses only Golang but we will specify the most important libs:

• github.com/gin-gonic/gin -> Used to create the web server facilities
• github.com/confluentinc/confluent-kafka-go/kafka -> Used to communicate with Kafka
• context -> Used to capture the background context of the application
• encoding/json -> Used to encode my struct to json format as byte array

Installation

To run this application you only have to open your terminal, go for the project directory and put this command: "go run ."

Development

This project was initiated by Gabriel Araujo Dantas a Brazilian Computer Engineer and my colleague Lucas Henrique A. de Paula a Brazilian Computer Scientist.

Docker

We begin the creation of Devops part that isn't the way we want, but we start the develop of this feature. For while, we have some important considerations:

• When you work with two docker-compose you need to create the network first (

  docker network create --driver=bridge  --subnet=172.18.0.0/16  --ip-range=172.18.0.0/24  --gateway=172.18.0.1   my_network
  

  ), this is necessary because you have use same network on all docker-compose

• After that you have to add on your kafka docker-compose this (

networks: 
  default: 
    external: 
      name: kafka_confluent_network

  )

• And now you have to run all docker-compose and you are ready to use this API

docker-compose up -d

or

docker-compose up -d --build

.

Important information

We use the JSON cloudevent.io specification so is important to send a event with these characteristics.

{
    "id": "ac47faa1-3f11-4d3e-8e53-41e29cdf4b0c", 
    "specVersion": "1.0", 
    "source": "/product/domain/subdomain/service", 
    "type": "br.com.example.correctTopic", 
    "time": "2022-03-22T17:41:02",
    "subject": "Estamos inserindo um evento no kafka da Confluent espia.", 
    "correlationID": "", 
    "dataContentType": "application/json", 
    "data": "{info1: \"A\"}"
}

If you want to create a topic you have to send this body:

{
    "topicName": "br.com.example.correctTopic",
    "numPartition": 1,
    "replicationFactor": 1
}

Another important information is we use the confluent kafka community for this test. You can find that on this link: https://github.com/confluentinc/cp-all-in-one/tree/7.0.1-post/cp-all-in-one-community