letsramp / sample-microservices

Sample cloud-first application forked from GoogleCloudPlatform/microservices-demo with added support for REST and Thrift APIs.

• Introduction
  • Use Cases
  • Implementation
• Usage
  • 1. Install pre-requisite tools
  • 2. Clone sample services
  • 3. Build and Push Images (Optional)
    • Build images from source
    • Push services to container registry
  • 4. Deploy
  • 5. Interacting with the microservices
    • Add to cart using gRPC API
    • Add to cart using REST API
    • Add to cart using Thrift API
    • Verify contents of cart
• Contributing Code

Introduction

This is a demo project based on GCP Online Boutique with added support for REST and Thrift APIs. It is designed to be used during cloud-native development for testing across different APIs–REST, gRPC, and Thrift. It is extensible in support of future functionality (e.g. GraphQL).

Use Cases

1. Use as a test project for developing cloud-native dev tools.
2. Learn how to implement Thrift (and REST) support for an existing project.

Implemented by the Skyramp team.

Implementation

For each microservice in the repo, REST and Thrift implementations open up separate ports to listen to the corresponding traffic. Implementations are in the rest.go and thrift.go files in the top-level directory for each service.

Default ports for REST and Thrift are hardcoded in the main.go file in each service directory. For example, the carts microservice has the following ports defined:

const (
	serverCrt         = "server.crt"
	serverKey         = "server.key"
	defaultThriftPort = "50000"
	defaultRestPort   = "60000"
)

Usage

1. Install pre-requisite tools

• docker
• curl (required for REST)
• jq (optional)
• kubectl (optional)

2. Clone sample services

git clone https://github.com/letsramp/sample-microservices.git
cd sample-microservices/src

3. Build and Push Images (Optional)

Images for sample-microservices are already available in a publically accessible registry. To use your own registry, follow these steps.

Build images from source

docker compose build

Push services to container registry

Update the host path/s in the docke-compose.yaml file to point to your own docker registry. Push images by running:

docker compose push

4. Deploy

Deploy Online Boutique by running the following command:

docker compose up

Now, familiarize yourself with the application by navigating to http://127.0.0.1:8080 on your browser.

📝 NOTE: If you are using Docker Desktop, you can look at the logs for cart service to see that we've opened up separate ports for gRPC(7070), REST(60000), and Thrift(50000) traffice to the service.

5. Interacting with the microservices

To demonstrate the REST and Thrift implementations, we've created simple clients (src/clients) for the "add to cart" scenario for each of the APIs. The client code is accessible from the clients container in the cluster.

To connect to the clients container, run the following command in your terminal:

docker compose exec -it clients ash

Optionally, you can download and install Docker Desktop to follow along.

If you are using Docker Desktop, click on the clients_1 container and go to the CLI from there.

Add to cart using gRPC API

1. In the clients container, navigate to the grpc/golang folder and download the required go modules.

cd /grpc/golang
go mod download

2. In the addCart.go file, you will notice that we open a connection to port 7070 of cart microservice which listens to grpc traffic.

conn, err := grpc.Dial("cartservice:7070", grpc.WithInsecure())

3. Run the code in the file to add an item to the cart.

go run ./cmd/cart

Expected result

Successfully added the item to the cart.

Having seen how to successfully add an item to the cart with a gRPC client calling the gRPC endpoint, we can see how to do the same through the REST and Thrift endpoints.

Add to cart using REST API

Since cURL is already installed in the clients container, you can issue a request directly from the CLI of the container to add an item to the cart.

curl -X 'POST' 'http://cartservice:60000/cart/user_id/abcde' \
  -H 'accept: application/json' \
  -H 'content-type: application/json' \
  -d '{
  "product_id": "OLJCESPC7Z",
  "quantity": 1
}'

Again, notice that the request is being sent to port 60000 of cart microservice which listens to REST traffic.

Result

{"success":"200 OK"}

Add to cart using Thrift API

1. In the clients container, navigate to the thrift/golang folder and download the required go modules for the Thrift client.

Setup

cd /thrift/golang
go mod download

2. In the addCart.go file, you will notice that we open a connection to port 50000 of cart microservice which listens to Thrift traffic.

clientAddr := "cartservice:50000"

3. Now, run the code in the file to add an item to the cart.

go run ./cmd/cart

Result:

"Successfully added the item to the cart."

Verify contents of cart

You can now fetch the contents of the cart using REST API to see that a total of 3 items were added (one using each supported API).

curl -X 'GET' \
  'http://cartservice:60000/cart/user_id/abcde' \
   -H 'accept: application/json'

Result:

{"user_id":"abcde","items":[{"product_id":"OLJCESPC7Z","quantity":3}]}

Contributing Code

PRs are welcome!

This project follows the CNCF Code of Conduct .