# README
grpcproxy
Example project with a gRPC client, server, and proxy. Demonstrates a reverse proxy for gRPC requests in Go.
The project includes a server that handles the chat.Greeter and chat.Echo services. A reverse grpc proxy supports forwarding the chat services. Two clients - echo and hello will send an echo request or a hello request.
This project demonstrates using mTLS for all connections.
Requirements
Install protobuf compiler
- Ubuntu:
apt install protobuf-compiler-grpc - macOS:
brew install protobuf
Install Go generator for protobuf and grpc:
go install google.golang.org/protobuf/cmd/protoc-gen-go@latest
go install google.golang.org/grpc/cmd/protoc-gen-go-grpc@latest
Build
A Makefile provides the following targets:
| Target | Use |
|---|---|
| build | Generate pb.go files from proto, a server and proxy keypair, and builds the client, proxy, and server |
| clean | Remove generated files |
| distclean | Remove everything including keypairs |
Running
The server and proxy should either run in separate shells or run in the background.
Server
By default, server listens on :8051 and looks for certificates in the current directory.
./dist/server
Proxy
By default, proxy listens on :8050, forwards to :8051 and looks for certficates in the current directory:
./dist/proxy
client
The client supports two commands:
hello echo
By default, it will send to server on :8051. Use -address to use proxy. The client uses certificates in the current directory by default.
# Send to server
./dist/client hello bob
# Send to proxy
./dist/client -address :8050 echo where are you sally?
Certificates
Running make keys will generate a self-signed keypair (ca.crt and ca.key) for a self-signed CA. Keypairs are created and signed by the CA for server, proxy, and client.
Ad-Hoc
Using gRPC server reflection, tools like grpcurl can be used for making ad-hoc requests.
Example:
grpcurl -cacert ca.crt -cert client.crt -key client.key localhost:8051 list
grpcurl -cacert ca.crt -cert client.crt -key client.key -d '{"name": "Bob"}' localhost:8051 chat.Greeter/SayHello
Response is in JSON:
{
"message": "Hello Bob"
}