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.