Each service has its own database:

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

Getting Started

1. Clone the repository:

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

2. Start the services using Docker Compose:

   docker compose up
   

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

Command to Generate Protobuf Files

To generate Go code from your .proto files, run:

protoc --go_out=./pb --go-grpc_out=./pb account.proto

Install protoc

To install protoc:

brew install protoc

Required Extensions

You need these plugins installed:

• protoc-gen-go
• protoc-gen-go-grpc

How to Install

Run these commands:

go install google.golang.org/protobuf/cmd/protoc-gen-go@latest
go install google.golang.org/grpc/cmd/protoc-gen-go-grpc@latest

Make sure your Go binaries path is in your PATH environment variable. Add this line to your shell profile (~/.bashrc or ~/.zshrc):

export PATH="$PATH:$(go env GOPATH)/bin"

Reload your shell or run source ~/.bashrc (or your profile) after adding the line.

Now protoc can find the plugins and generate Go and gRPC code correctly.

GraphQL API Usage

The GraphQL API provides a unified interface to interact with all the microservices.

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
    }
  }
}

Access Elastic Search for Catalog DB

After the app is up and running, ElasticSearch DB can be accessed at:

http://localhost:9200

To check all indices visit:

http://localhost:9200/_cat/indices?v

To check all documents in the catalog index:

http://localhost:9200/catalog/_search?pretty

Access Postgres for Account DB

PostgreSQL can be accessed and used via CLI (Command Line Interface) After the app is up and running, in the terminal follow the below commands:

docker exec -it <container_id_for_accountDB> psql -U <db_username> -d <db_name>

Once you are in the PostgreSQL CLI, use the following commands:

To view tables:

\dt

To view accounts information:

SELECT * FROM accounts;

Access Postgres for Orders DB

PostgreSQL can be accessed and used via CLI (Command Line Interface) After the app is up and running, in the terminal follow the below commands:

docker exec -it <container_id_for_orderDB> psql -U <db_username> -d <db_name>

Once you are in the PostgreSQL CLI, use the following commands:

To view tables:

\dt

To view orders information:

SELECT * FROM order;