Inter-service communication (Go + gRPC): browse a product catalogue, place orders, and watch live shipment tracking wired together through real gRPC streams.
Browser (SSE) ──▶ HTTP Gateway (:8080)
│
┌──────────┼──────────────────┐
│ │ │
ProductService OrderService ShippingService
(:9001) (:9003) (:9002)
gRPC srv gRPC srv gRPC srv
gRPC client ──────▶ (calls Shipping internally)
| Layer | What it does |
|---|---|
| proto/ | Source of truth — three .proto files define every RPC |
| gen/ | Auto-generated Go structs + gRPC stubs (make gen) |
| services/product | ProductService — streams the catalogue via server-side streaming |
| services/shipping | ShippingService — creates shipments, streams tracking updates |
| services/order | OrderService — places orders, calls ShippingService over gRPC as a client |
| gateway/ | Thin HTTP layer: translates REST+SSE → gRPC for the browser |
| frontend/ | Static HTML/JS — uses EventSource to consume SSE streams |
| cmd/server | Single binary that boots all three gRPC servers + the HTTP gateway |
| Pattern | Where |
|---|---|
| Server-side streaming | ProductService.ListProducts — streams products one by one |
| Server-side streaming | ShippingService.TrackShipment — streams live status updates |
| Server-side streaming | OrderService.ListOrders — streams all orders |
| Unary RPC | OrderService.PlaceOrder, ShippingService.CreateShipment, etc. |
| Service-to-service gRPC | OrderService dials ShippingService as a gRPC client |
| Tool | Version | Install |
|---|---|---|
| Go | 1.22+ | https://go.dev/dl |
| buf | latest | https://buf.build/docs/installation |
| Docker | any recent | https://docs.docker.com/get-docker |
# 1. Clone and enter the project
git clone https://github.com/preetDev004/gRPC-ISC grpc-isc
cd grpc-isc
# 2. Generate protobuf / gRPC Go code
make gen # runs buf dep update && buf generate && go mod tidy
# 3. Run the server
make run # starts on http://localhost:8080Open http://localhost:8080 in your browser.
# Build the image and start the container
make docker-run
# Open the app
open http://localhost:8080
# Stop
make docker-stopThe Dockerfile is a three-stage build:
- proto-gen — uses the official
bufbuild/bufimage to runbuf generate - builder — compiles a statically-linked Go binary
- runtime — copies only the binary + frontend into a
scratchimage (~10 MB total)
With the server running locally, you can hit the gRPC endpoints directly:
# List all products (server-streaming)
grpcurl -plaintext -d '{}' localhost:9001 shop.ProductService/ListProducts
# Get a single product
grpcurl -plaintext -d '{"product_id":"prod-003"}' localhost:9001 shop.ProductService/GetProduct
# Place an order
grpcurl -plaintext -d '{
"product_id": "prod-001",
"quantity": 2,
"customer": "Preet Patel",
"address": "123 King St W, Toronto ON"
}' localhost:9003 shop.OrderService/PlaceOrder
# Track a shipment (server-streaming) — use the shipping_id from PlaceOrder response
grpcurl -plaintext -d '{"shipping_id":"ship-XXXXXXXX"}' localhost:9002 shop.ShippingService/TrackShipment
# List all orders
grpcurl -plaintext -d '{}' localhost:9003 shop.OrderService/ListOrders
