This is the backend Implementation of express and socket server for creating scalable chat application.

Dependencies

• MongoDB
• Redis
  • Using bullMQ library and it uses the redis to store the queue data.
  • By using queues I'm trying to reduce the time taken by DB operations. and after sending the message I'm adding the messages inot DB asynchronously.

Run the code locally

• Clone the repo: git clone https://github.com/VivekSite/chat_app_backend.git.
• Install the MongoDB community version or we can also use connection string to connect with the MongoDB atlas.
• Same for Redis we can install redis server locally.
  • For MacOS run brew install redis.
  • For Linux run sudo apt install redis-server.
• Install all the other dependencies: yarn install.
• Now lets update the .env file
  • copy the .env.example file cp .env.example .env

    NODE_ENV=development
    PORT=8080
    MONGO_URI=mongodb://localhost:27017/chat_application
    REDIS_URL=redis://localhost:6379
  
    ACCESS_TOKEN_SECRET='*******************************************'
    REFRESH_TOKEN_SECRET='*******************************************'
    HASH_SECRET='*******************************************'
    OTP_SECRET='*******************************************'
  
    EMAIL_SENDER=example@gmail.com
    EMAIL_PASS_KEY='abcd efgh ijkl mnop'
  

  • Update all the secrets. we can use following command to generate the secrets:
  • openssl rand -hex 64
  • For EMAIL_PASS_KEY we can generate the App Password from https://myaccount.google.com
• Start the development server: yarn run dev.

we can also use npm to run the scripts