This is an example project of connecting two distinct applications over gRPC.

The gRPC server is written in ruby, and can be ran from the main directory, ruby ./server.rb. This starts a gRPC server on port 50051.

class CacheHubServer
  class << self
    def start
      start_grpc_server
    end

    private
    def start_grpc_server
      puts 'cache hub server up'
      @server = GRPC::RpcServer.new
      @server.add_http2_port('0.0.0.0:50052', :this_port_is_insecure)
      @server.handle(CacheHubService)
      @server.run_till_terminated
    end
  end
end

---

There are currently only 2 methods defined in the cache.proto file:

StatusRequest

• Used for basic health check on the server

Upload

• Used as the main file transfer stream method

service CacheHub {
  rpc GetStatus(StatusRequest) returns (StatusResponse) {}
  rpc Upload(stream Chunk) returns (UploadStatus) {}
}

---

Client

The gRPC client in written in Go, and can be found in /golang_client/. You can interact with the client from the command line:

> go run client.go -h
  -a string
        action to preform.  status, get, store
  -f string
        file name
exit status 2

To store a file in memcache:

> go run client.go -a=store -f=/path/to/file/myfile.pdf

To get a file from the cache:

go run client.go -a=get -f=myfile.pdf

File Location: /tmp/myfile.pdf -- md5: 61e4b830ec5baea0fa9ff430e8ddcfa7%

Note: this returns a file path location from the local system, for learning purposes only.

---

The Ruby FileHandler and CacheBroker classes

TODO: Documentation

---

Misc Notes:

To generate go client files:

protoc -I ../protos ../protos/cache.proto --go_out=plugins=grpc:cache

To generate ruby server files:

grpc_tools_ruby_protoc -I protos --ruby_out=lib --grpc_out=lib protos/cache.proto

To start ruby gRPC server:

ruby ./server.rb