Ecommerce Backend App

This is an example eCommerce backend application built using Node.js and Kafka. The app allows you to create orders and updates the product stock accordingly.

Getting Started

To run the app, follow these steps:

1. Make sure you have Docker installed on your machine.
2. Clone this repository to your local machine.
3. Open a terminal and navigate to the project's root directory.
4. Run the following command to start the app and its dependencies:

docker-compose up

This command will spin up the main two services, order-service, and product-service, along with the required dependencies (Kafka, ZooKeeper, MongoDB).

Usage

Order Creation

To create an order, send a POST request to the order-service API:

URL: http://localhost:3000/orders

Request Body (JSON):

{
  "orderId": "1",
  "productId": "1",
  "quantity": "1"
}

This will create a new event in Kafka, indicating the details of the order.

Product Stock

When the app is running, the product-service will monitor the MongoDB database for changes. Initially, the `products` collection in the MongoDB database will have a record like this:

{
  "_id": {
    "$oid": "647f9230793eafd61be5e6ad"
  },
  "orderId": "1",
  "productId": "1",
  "quantity": 10
}

Whenever a new order is created, the product-service will consume the event from Kafka and automatically decrease the stock of the corresponding product. For example, after consuming the order event, the product's quantity will be updated to:

{
  "_id": {
    "$oid": "647f9230793eafd61be5e6ad"
  },
  "orderId": "1",
  "productId": "1",
  "quantity": 9
}

This ensures that the product stock is accurately maintained based on the orders received.

Contributing

Contributions to this project are welcome. If you encounter any issues or have suggestions for improvement, please open an issue or submit a pull request.

License

This project is licensed under the MIT License.