Unix Domain Socket Communication

client.go

package main

import (
	"log"
	"net"
	"time"
)


func main() {
	conn, err := net.Dial("unix", "../uds_go.sock")
	if err != nil {
		log.Fatal("Dial error", err)
	}
	defer conn.Close()

	go func (conn net.Conn) {
		buf := make([]byte, 1024)
		for {
			len, err := conn.Read(buf[:])
			if err != nil {
				return
			}
			log.Println("<<", string(buf[0:len]))
		}
	}(conn)

	for {
		msg := "hello world"
		_, err := conn.Write([]byte(msg))
		if err != nil {
			log.Fatal("send to server error", err)
			break
		}
		log.Println("<", msg)
		time.Sleep(1e9)
	}
}

client.py

import socket
import time


socket_path = '../uds_socket_py'

with socket.socket(socket.AF_UNIX, socket.SOCK_STREAM) as sock:
    sock.connect(socket_path)

    while True:
        msg = b'Message from client.'
        print('client sending {!r}'.format(msg))
        sock.sendall(msg)

        amount_recv = 0
        amount_expect = len(msg)

        while amount_recv < amount_expect:
            data = sock.recv(8)
            amount_recv += len(data)
            print('received: {!r}'.format(data))

        print('...')
        time.sleep(1)

    print('close client socket')

server.go

package main

import (
	"log"
	"net"
	"os"
)

const sockAddr = "../uds_go.sock"

func main() {
	if _, err := os.Stat(sockAddr); err == nil {
		if err := os.Remove(sockAddr); err != nil {
			log.Printf("Remove socket file error: %v", err)
		}
	}

	sock, err := net.Listen("unix", sockAddr)
	if err != nil {
		log.Fatal("Listen error: ", err)
	}
	defer sock.Close()

	for {
		conn, err := sock.Accept()
		if err != nil {
			log.Fatal("Accept error: ", err)
		}

		go func(conn net.Conn) {
			for {
				buf := make([]byte, 1024)
				len, err := conn.Read(buf[:])
				if err != nil {
					return
				}
				data := buf[0:len]
				log.Println(">", string(data))
				data = append(data, "@@@"...)
				_, err = conn.Write(data)
				if err != nil {
					log.Fatal("Send to client error: ", err)
				}
			}
		}(conn)
	}
}

server.py

import socket
import pathlib


socket_path = '../uds_socket_py'
path = pathlib.Path(socket_path)
if path.exists():
    print('delete socket file')
    path.unlink()

# UDS
with socket.socket(socket.AF_UNIX, socket.SOCK_STREAM) as sock:
    sock.bind(socket_path)
    sock.listen(1)
    while True:
        print('waiting for connection')
        conn, client = sock.accept()
        with conn:
            print('connection from', client)
            while True:
                data = conn.recv(16)
                print('received {!r}'.format(data))
                if data:
                    print('send back')
                    conn.sendall(data)
                else:
                    print('EOF')
                    break