Why I keep getting timeout with gen_tcp in Elixir?

I am trying to implement a simple Server (in Go) / Client (in Elixir).

However, I keep getting timeouts on Elixir side before my request reaches the server.

Server

package main

import (
	"fmt"
	"net"
	"net/http"
	"os"
)

func main() {
	socket := "/tmp/ipc_test.sock"
	os.Remove(socket)

	listener, err := net.Listen("unix", socket)
	if err != nil {
		fmt.Printf("Error listening on unix socket: %s\n", err)
		return
	}

	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
		param := r.URL.Query().Get("param")
		fmt.Printf("%s", param)
		fmt.Fprint(w, param)
	})

	fmt.Printf("Server listening on %s\n", socket)
	http.Serve(listener, nil)
}

Client

defmodule IpcTest do
  def make_request(socket, request) do
    :gen_tcp.send(socket, request)
    {:ok, response} = :gen_tcp.recv(socket, 0)

    :gen_tcp.close(socket)
    response
  end

  def print_responses(responses) do
    responses
    |> Enum.each(&IO.puts/1)
  end

  def run(num_requests) do
    1..num_requests
    |> Enum.map(fn i ->
      request = "/?param=#{i}"

      Task.async(fn ->
        {:ok, socket} =
          :gen_tcp.connect({:local, "/tmp/ipc_test.sock"}, 0, [:binary, packet: 4, active: false])

        make_request(socket, request)
      end)
    end)
    |> Enum.map(&Task.await/1)
  end
end

> go run src/main.go
Server listening on /tmp/js_runner.sock

As you can see, the server seems to be running fine.
However, I am getting the following error in my client.

> iex -S mix
> IpcTest.run 1
** (exit) exited in: Task.await(%Task{mfa: {:erlang, :apply, 2}, owner: #PID<0.237.0>, pid: #PID<0.263.0>, ref: #Reference<0.3740412160.2895708166.190144>}, 5000)
    ** (EXIT) time out
    (elixir 1.14.2) lib/task.ex:830: Task.await/2
    (elixir 1.14.2) lib/enum.ex:1658: Enum."-map/2-lists^map/1-0-"/2
    iex:2: (file)

By default, the :gen_tcp.connect/3 function has a timeout value of 5000 milliseconds (5 seconds). Increase to 10:

{:ok, socket} = :gen_tcp.connect({:local, "/tmp/ipc_test.sock"}, 10000, [:

But you should also try stuff like

socat - UNIX-CONNECT:/tmp/ipc_test.sock

Or the other stuff in: https://unix.stackexchange.com/questions/26715/how-can-i-communicate-with-a-unix-domain-socket-via-the-shell-on-debian-squeeze

to see if the socket file is even working for ANY normal linux cli tool.

Figured it out! My issue was actually in the Go based server.

Here is the updated code if anyone is interested in:

package main

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

const SockAddr = "/tmp/ipc_test.sock"

func echoServer(c net.Conn) {
	log.Printf("Client connected [%s]", c.RemoteAddr().Network())
	io.Copy(c, c)
	c.Close()
}

func main() {
	if err := os.RemoveAll(SockAddr); err != nil {
		log.Fatal(err)
	}

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

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

		go echoServer(conn)
	}
}

Reference: https://eli.thegreenplace.net/2019/unix-domain-sockets-in-go