Order Service

Order Service is a simple Web API.

Principles and patterns that I use:

• Clean Architecture
• Experiments with DDD
• CQRS (All but one method use half of the CQRS; GetAllOrdersByUserID uses the cache)
• Outbox Pattern
• Saga Pattern(Choreography-based)
• Mediator with Query and Command Bus(MediatR inspired)

To use Saga pattern need external CustomerService or you can simulate events with RabbitMQ admin panel

Endpoints

GET /healthcheck/

curl -X "GET" "http://localhost:8000/healthcheck/"

{"status": "OK"}

To create order need some product, address and client.

POST /products/

curl -X "POST" \
  "http://localhost/api/v1/products/" \
  -d '{
    "productID": "ec14f9be-44e3-4ec0-97d3-47fdac6c55c9",
    "price": 100,
    "discount": 10,
    "Description": "string",
    "Name": "string"
}`

Status 204 No Content

POST /address/

curl -X "POST" \
  "http://localhost/api/v1/address/" \
  -d '{
    "addressID": "7b2b575e-65e7-427c-bb1b-1fe609fc1f6b",
    "buildingNumber": 44,
    "streetName": "string",
    "city": "string",
    "country": "string"
}`

Status 204 No Content

POST /users/

curl -X "POST" \
  "http://localhost/api/v1/users/" \
  -d '{
    "userID": "4b2b575e-65e7-427c-bb1b-1fe609fc1f6b",
    "username": "string",
    "addressID": "7b2b575e-65e7-427c-bb1b-1fe609fc1f6b"
}`

Status 204 No Content

POST /orders/

curl -X "POST" \
  "http://localhost/api/v1/orders/" \
  -d '{
    "orderID": "1b2b434e-44e8-424c-bb1b-1fe609fc1f7d",
    "paymentMethod": "string",
    "productsIds": ["ec14f9be-44e3-4ec0-97d3-47fdac6c55c9"],
    "userID": "4b2b575e-65e7-427c-bb1b-1fe609fc1f6b",
    "deliveryAddress": "7b2b575e-65e7-427c-bb1b-1fe609fc1f6b"
}`

After creating an order, need to imitate a response from a third-party service

RabbitMQ

• CustomerSaga Queue Payload

{
    "orderID": "1b2b434e-44e8-424c-bb1b-1fe609fc1f7d",
    "orderType": "Approved"
}

After publish payload can get orders:

GET /orders/

• From DB

curl -X "GET" "http://localhost:8000/api/v1/orders?limit=10&order=asc"

{
    "orders": [
        {
            "orderStatus": "New",
            "paymentMethod": "Online",
            "client": {
                "ClientID": "4b2b575e-65e7-427c-bb1b-1fe609fc1f6b",
                "ClientName": "test"
            },
            "address": "Russia, Moscow, Pushkina, 44",
            "OrderID": "1b2b434e-44e8-424c-bb1b-1fe609fc1f7d",
            "serialNumber": 1,
            "products": [
                {
                    "productID": "ec14f9be-44e3-4ec0-97d3-47fdac6c55c9",
                    "name": "he3444443h1",
                    "actualPrice": 90
                }
            ],
            "createdAt": "2023-07-23T00:27:52.641012+03:00",
            "totalPrice": 90
        }
    ],
    "count": 1,
    "limit": 10,
    "order": "asc"
}

GET /orders/user/:id

• From Redis Cache

curl -X "GET" "http://localhost:8000/api/v1/orders/user/4b2b575e-65e7-427c-bb1b-1fe609fc1f6b?limit=10&order=desc"

{
    "orders": [
        {
            "orderStatus": "New",
            "paymentMethod": "Online",
            "client": {
                "ClientID": "4b2b575e-65e7-427c-bb1b-1fe609fc1f6b",
                "ClientName": "test"
            },
            "address": "Russia, Moscow, Pushkina, 44",
            "OrderID": "1b2b434e-44e8-424c-bb1b-1fe609fc1f7d",
            "serialNumber": 1,
            "products": [
                {
                    "productID": "ec14f9be-44e3-4ec0-97d3-47fdac6c55c9",
                    "name": "he3444443h1",
                    "actualPrice": 90
                }
            ],
            "createdAt": "2023-07-23T00:32:00.414866435+03:00",
            "totalPrice": 90
        }
    ],
    "count": 1,
    "limit": 10,
    "order": "desc"
}

Dependencies

Infrastructure

• Postgres — Database
• RabbitMQ — The queue used to publish and handle events
• Redis — For Query cache
• Docker — For deployment

Grafana stack

• Grafana — Web view for logs and prometheus info
• Loki — A platform to store and query logs
• Vector.dev — A tool to collect logs and send them to Loki
• Prometheus — A tool to alerting series info

Golang libs

• Gin - Web framework
• Gorm - ORM for working with database
• go-redis - Cache database for query request
• cron - To implement relay from Outbox pattern
• fx - A dependency injection tool for easy initialization and delivery of dependencies
• zap - For better logging config
• amqp091-go - For working with RabbitMQ

Setup

The first thing to do is to clone the repository:

git clone https://github.com/MikhailGulkin/CleanGolangOrderApp
cd CleanGolangOrderApp

After that create .env and configs/app/prod.toml. Examples for use lie next to these files. Run following command

make up-prod

TODO

• Refactoring auto-tests
• Configure CI
• Create simple CustomerService