Go Microservice with GraphQL API(gRPC)

This project demonstrates a microservices architecture using gRPC for inter-service communication and GraphQL as the API gateway. It includes services for account management, product catalog, and order processing.

Project Structure

The project consists of the following main components:

• Account Service
• Catalog Service
• Order Service
• GraphQL API Gateway

Each service has its own database:

• Account and Order services use PostgreSQL
• Catalog service uses Elasticsearch

Tech Stacks

• gRPC (v1.68.0)
• Golang (golang:1.23.3)
• Docker (26.0.0)
• Graphql
• Postgres (postgres:10.3)
• Elasticsearch (elasticsearch:8.6.0)

Code flow

mutation or query → client →(gRpc)→ server → service → repository → database

Frequently used Commmands

protoc -I=. --go_out=. --go-grpc_out=. account.proto

protoc -I=. --go_out=. --go-grpc_out=. catalog.proto

protoc -I=. --go_out=. --go-grpc_out=. order.proto

Getting Started

1. Clone the repository:

   git clone <repository-url>
   cd <project-directory>
   

2. Start the services using Docker Compose:

   docker-compose up -d --build
   

3. Access the GraphQL playground at http://localhost:8000/playground

GraphQL API

Query Accounts

query {
  accounts {
    id
    name
  }
}

Create an Account

mutation {
  createAccount(account: {name: "New Account"}) {
    id
    name
  }
}

Query Products

query {
  products {
    id
    name
    price
  }
}

Create a Product

mutation {
  createProduct(product: {name: "New Product", description: "A new product", price: 19.99}) {
    id
    name
    price
  }
}

Create an Order

mutation {
  createOrder(order: {accountId: "account_id", products: [{id: "product_id", quantity: 2}]}) {
    id
    totalPrice
    products {
      name
      quantity
    }
  }
}

Query Account with Orders

query {
  accounts(id: "account_id") {
    name
    orders {
      id
      createdAt
      totalPrice
      products {
        name
        quantity
        price
      }
    }
  }
}

Advanced Queries

Pagination and Filtering

query {
  products(pagination: {skip: 0, take: 5}, query: "search_term") {
    id
    name
    description
    price
  }
}

Calculate Total Spent by an Account

query {
  accounts(id: "account_id") {
    name
    orders {
      totalPrice
    }
  }
}