Order Listing Service

This project is an implementation of a simple order listing service using gRPC, GraphQL, and REST API. It demonstrates how to create a multi-service application with a shared PostgreSQL database using Docker Compose.

Table of Contents

1. Prerequisites
2. Create .env file
3. Run the Application
4. Run Migrations
5. Insert Sample Data
6. Testing the Services
   • REST API
   • GraphQL
   • gRPC
7. Clean Up

1. Prerequisites

• Docker
• Docker Compose
• Go
• grpcurl (for testing gRPC services)

2. Create .env file

Create a .env file in the root directory of the project with the following content:

DB_USER=user
DB_PASSWORD=password
DB_NAME=orders_db
DB_HOST=db
DB_PORT=5432

3. Run the Application

First, make sure Docker is running, then execute the following commands:

docker-compose build
docker-compose up -d

This will build the application and start all the services defined in the docker-compose.yml file.

4. Run Migrations

Migrations will be automatically run by the migrate service defined in docker-compose.yml.

5. Testing the Services

REST API

You can test the REST API using curl or any API testing tool like Postman. The REST API will be available at http://localhost:8080.

curl -X POST -H "Content-Type: application/json" -d '{"user_id": 1, "product_id": 101, "quantity": 2, "status": "pending"}' http://localhost:8080/order

curl http://localhost:8080/order

GraphQL

You can test the GraphQL API using the GraphQL Playground available at http://localhost:8081/playground.

Create Order:

mutation {
  createOrder(user_id: 1, product_id: 101, quantity: 3, status: "pending") {
    id
    user_id
    product_id
    quantity
    status
    created_at
    updated_at
  }
}

List Orders:

query {
  listOrders {
    id
    user_id
    product_id
    quantity
    status
    created_at
    updated_at
  }
}

gRPC

You can test the gRPC service using grpcurl. The gRPC service will be available at localhost:50051.

grpcurl -plaintext localhost:50051 list

Create Order

grpcurl -plaintext -d '{
  "user_id": 1,
  "product_id": 101,
  "quantity": 3,
  "status": "pending"
}' localhost:50051 order.OrderService/CreateOrder

List Orders

grpcurl -plaintext -d '{}' localhost:50051 order.OrderService/ListOrders

6. Clean Up

To stop and remove all the containers, network, and volumes, run the following command:

docker-compose down -v