check fort port ready

lib/port_checker.ex

@@ -0,0 +1,33 @@
+# SPDX-License-Identifier: Apache-2.0
+defmodule TestcontainersElixir.PortChecker do
+  def wait_for_port(ip, port, timeout \\ 1000) do
+    wait_for_port(ip, port, timeout, :os.system_time(:millisecond))
+  end
+
+  defp wait_for_port(ip, port, timeout, start_time) do
+    if timeout + start_time < :os.system_time(:millisecond) do
+      {:error, :timeout}
+    else
+      if port_open?(ip, port) do
+        {:ok, :port_is_open}
+      else
+        # Sleep for 500 ms, then retry
+        :timer.sleep(500)
+        wait_for_port(ip, port, timeout, start_time)
+      end
+    end
+  end
+
+  defp port_open?(ip, port, timeout \\ 1000) do
+    IO.inspect("checking port #{port}")
+
+    case :gen_tcp.connect(~c"#{ip}", port, [:binary, active: false], timeout) do
+      {:ok, socket} ->
+        :gen_tcp.close(socket)
+        true
+
+      {:error, _reason} ->
+        false
+    end
+  end
+end

lib/reaper.ex

@@ -20,6 +20,7 @@ defmodule TestcontainersElixir.Reaper do
   @impl true
   def init(connection) do
     Process.flag(:trap_exit, true)
+
     with {:ok, _image_create_response} <-
            Api.Image.image_create(connection, fromImage: @ryuk_image),
          {:ok, %Model.ContainerCreateResponse{Id: container_id}} <-

test/simple_test.exs

@@ -1,12 +1,14 @@
 defmodule SimpleTest do
   use ExUnit.Case
   import TestcontainersElixir.ExUnit
+  alias TestcontainersElixir.PortChecker
   alias TestcontainersElixir.Container
 
   test "creates and reaps container" do
     {:ok, container} = container(image: "nginx:latest", port: 80)
 
     port = Container.mapped_port(container, 80)
+    PortChecker.wait_for_port("localhost", port, 5000)
 
     {:ok, 200, _headers, body_ref} = :hackney.get("http://localhost:#{port}")
     {:ok, body} = :hackney.body(body_ref)