import argparse import logging import secrets import multiaddr import trio from libp2p import ( new_host, ) from libp2p.abc import PeerInfo from libp2p.crypto.secp256k1 import ( create_new_key_pair, ) from libp2p.discovery.events.peerDiscovery import peerDiscovery logger = logging.getLogger("libp2p.discovery.mdns") logger.setLevel(logging.INFO) handler = logging.StreamHandler() handler.setFormatter( logging.Formatter("%(asctime)s - %(name)s - %(levelname)s - %(message)s") ) logger.addHandler(handler) # Set root logger to DEBUG to capture all logs from dependencies logging.getLogger().setLevel(logging.DEBUG) def onPeerDiscovery(peerinfo: PeerInfo): logger.info(f"Discovered: {peerinfo.peer_id}") async def run(port: int) -> None: secret = secrets.token_bytes(32) key_pair = create_new_key_pair(secret) listen_addr = multiaddr.Multiaddr(f"/ip4/0.0.0.0/tcp/{port}") peerDiscovery.register_peer_discovered_handler(onPeerDiscovery) print( "Run this from the same folder in another console to " "start another peer on a different port:\n\n" "mdns-demo -p \n" ) print("Waiting for mDNS peer discovery events...\n") logger.info("Starting peer Discovery") host = new_host(key_pair=key_pair, enable_mDNS=True) async with host.run(listen_addrs=[listen_addr]), trio.open_nursery() as nursery: # Start the peer-store cleanup task nursery.start_soon(host.get_peerstore().start_cleanup_task, 60) await trio.sleep_forever() def main() -> None: description = """ This program demonstrates mDNS peer discovery using libp2p. To use it, run 'mdns-demo -p ', where is the port number. Start multiple peers on different ports to see discovery in action. """ parser = argparse.ArgumentParser(description=description) parser.add_argument("-p", "--port", default=0, type=int, help="source port number") parser.add_argument( "-v", "--verbose", action="store_true", help="Enable verbose output" ) args = parser.parse_args() if args.verbose: logger.setLevel(logging.DEBUG) try: trio.run(run, args.port) except KeyboardInterrupt: logger.info("Exiting...") if __name__ == "__main__": main()