client.go

package main

import (
	"log"
	"net"
)

func main() {
	addr, err := net.ResolveUnixAddr("unix", "./foo.sock")
	if err != nil {
		log.Fatal(err)
	}

	conn, err := net.DialUnix("unix", nil, addr)
	if err != nil {
		log.Fatal(err)
	}
	defer conn.Close()

	conn.Write([]byte("Hello"))
}

server.go

package main

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

func main() {
	l, err := net.ListenUnix("unix", &net.UnixAddr{
		Name: "./foo.sock",
		Net:  "unix",
	})
	if err != nil {
		log.Fatal(err)
	}
    defer l.Close()
    defer os.Remove("./foo.sock")

    for {
        conn, err := l.AcceptUnix()
        if err != nil {
            log.Fatal(err)
        }
        var b [1024]byte
        conn.Read(b[:])
        fmt.Println(string(b[:]))
        conn.Close()
    }
}