Test P2P Network

Small playground for experimenting with peer-to-peer style messaging using Go, gRPC, and a simple CLI.

Requirements

• Go 1.17+
• protoc with the Go gRPC plugin (only needed if you edit .proto files)

Setup

go get -u
go mod tidy

Regenerate protobufs after changing pkg/ping/ping.proto:

protoc --go_out=plugins=grpc:. --go_opt=paths=source_relative pkg/ping/ping.proto

CLI overview

go run ./main.go --help

Command	Description
pingTest	Spins up two demo nodes, has them ping one another, exits
start	Starts a node plus interactive shell (send, exit)

Quick demo (ping test)

go run ./main.go pingTest

This launches nodes on 127.0.0.1:10000 and 127.0.0.1:10001, waits briefly, then has each node ping the other.

Interactive shell

Start a node with sane defaults:

go run ./main.go start

Useful flags:

• --address / -a – host:port to bind the local gRPC server (must exist on your box)
• --listener-addresses / -l – known peers in host:port form (repeatable flag)
• --name / -n – friendly node name (defaults to a UUID)
• --log-file – where to write node logs (default logs/<address>.log)
• --verbose – also stream logs to the interactive console

Every ping reply carries the sender's peer list, so after a node successfully reaches any peer it will automatically learn about the rest of the network. The --listener-addresses flag is only needed to provide the initial bootstrap(s).

Two-node local test

Terminal 1:

go run ./main.go start \
  --address 127.0.0.1:10000 \
  --listener-addresses 127.0.0.1:10001

Terminal 2:

go run ./main.go start \
  --address 127.0.0.1:10001 \
  --listener-addresses 127.0.0.1:10000

Now type send hello in Terminal 2. Both terminals print live → / ← notifications showing who sent or received the payload, so you can watch the message propagate even without verbose logging enabled. Either shell accepts:

• send <message> – ping every known peer with the provided payload
• add-peer <host:port> – add new peers while the node keeps running
• peers – list known peers plus their last-seen timestamp
• exit – stop the gRPC server and quit the shell

If you supply an address you do not own (for example 172.0.0.1), the OS will return bind: can't assign requested address.