Book-microservice

This project aims to implement 4 microservices pertaining to serving books as content.

Instructions

Run the docker compose yaml file to start.

docker-compose -f docker-compose.yaml up

System Design

Features

• Built a scalable backend system to serve books as contents.
• Dockerized entire application including all services and databases for easy deployement.
• Used Nginx as a reverse proxy to cater requests to different services.
• Used RabbitMQ as the Message-Broker to publish message from User Service to Email Service after which an email will be sent to the newly regsitered user.
• User can filter books based on the basis of likes or reads interactions.
• Implemented database using Mongodb for all three services.

System Architecture

This diagram illustrates how this project's backend works.

Diagram Code

Title: Backend Architecture
participant client
participant Nginx Server as proxy
participant Contents server as webserver
participant controller
participant service
participant domain
participant database

client -> proxy:  POST /api/v1/Contents
proxy -> webserver:  POST /api/v1/Contents
webserver -> controller: post_content_handler()
controller -> service: content_service(user_id)
service -> domain: content_domain(user_id)
domain -> database: domain_model
domain -> service: document
service -> controller: data
controller -> webserver: JSON or HTML Response
webserver -> proxy: HTTP Response
proxy -> client: HTTP Response

Database Schema

Users
_id:ObjectId
name:string
email:string
password:Number
phoneno:ObjectId

Contents
_id:ObjectId
user_id:String
title:String
story:String
created_at:Datetime

User_events
_id:ObjectId
content_id:ObjectId
liked_by:list_of_strings
read_by:list_of_strings

User Service

• User service deals with user registration and login.
• Jwt tokens is used to authorize the incoming user's request in all the services.

Rest Apis

 register new user          POST     http:://api/v1/users/register

 Login current user         GET      http:://api/v1/users/login

 update phoneno             PATCH    http:://api/v1/users/updatephone

 update password            PATCH    http:://api/v1/users/updatepassword

 update name                PATCH    http:://api/v1/users/updatename
 
 delete user                DELETE   http:://api/v1/users

• Request

 curl -X POST -d '{"name":"chirag","email":"chirag@example.com","password":"abc1","phoneno":8123456789}' \
 http://localhost:80/api/v1/users/register \
 --header 'Content-Type: application/json'

• Response Body: 201

 {
  "result": {
      "name": "Chirag",
       "email": "chirag@example.com",
       "password": "abc1",
       "phoneno": 8123456789,
       "_id": "61f77e267aceb6f9e51c25b3",
     }        
 }

Email Service

• Email service sends greeting mail to the newly registered users.
• It consumes events from Message queue published by User service after new registration.
• Email is sent using node mailer.

Content Service

• Serving books as content. A content will have a story and title as contents.
• Content service should have atleast the title, story, date published and the user id stored.
• A user will be able to create, update and delete contents.

Rest Apis

 post new content             POST    http:://api/v1/contents/

 get newly added contents     GET     http:://api/v1/users/new

 get top liked contents       GET     http:://api/v1/contents/top/liked

 get top read contents        GET     http:://api/v1/contents/top/read

 get content by id            GET     http:://api/v1/contents/:id
 
 update story                 PATCH   http:://api/v1/contents/:id/update-story
 
 update title                 PATCH   http:://api/v1/contents/:id/update-title
 
 delete content               DELETE  http:://api/v1/contents/:id

• Request

curl -H "Authorization: Bearer <Token>" http://localhost:80/api/v1/contents/new \
--header 'Content-Type: application/json'

• Response

"result": 
{
  [
    {
       "_id": "61f82deddaa122263e6f0c22",
       "title": "Interstellar",
       "story": "No Time for caution",
       "user_id": "61f82b9d2dfca828d5238e2c",
       "createdAt": "2022-01-31T18:43:57.980Z",
    },
    {
       "_id": "61f82ba9daa122263e6f0c1d",
       "title": "HEllo world",
       "story": "Random story",
       "user_id": "61f82b9d2dfca828d5238e2c",
       "createdAt": "2022-01-31T18:34:17.596Z"
    },
    {
       "_id": "61f82ba8daa122263e6f0c1b",
       "title": "Toy story",
       "story": "To infity and beyond",
       "user_id": "61f82b9d2dfca828d5238e2c",
       "createdAt": "2022-01-31T18:34:16.177Z"
    }
  ]
}

User interaction service

• User Interaction service is basically to record events done by the user. In this case the service records 2 types of events - Like and Read.
• Like - The content liked by the current user.
• Read - The content i.e book completely read by the user.
• This service exposes API for content service inorder to fetch top contents based on likes and reads count since these 2 events data is stored in User_events database.

Rest Apis

 Like a content                          PUT    http:://api/v1/interact/like

 Comepleted reading a content            PUT    http:://api/v1/interact/read

 get like interaction on given content   GET    http:://api/v1/interact/:content_id/likes
 
 get read interaction on given content   GET    http:://api/v1/interact/:content_id/read

• Request

 curl -X PUT -H "Authorization: Bearer <Token>" http://localhost:80/api/v1/interact/like?content_id=61f82ba9daa122263e6f0c1d \
 --header 'Content-Type: application/json'

• Response

{
   "success": true
}