dotnet-core/runtime/Program.cs

﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using System.Net;
using System.Net.Sockets;

namespace runtime
{
    class Program
    {
        static void Main(string[] args)
        {
            string port = Environment.GetEnvironmentVariable("PORT");
            TcpListener server = new TcpListener(IPAddress.Any, Int32.Parse(port));

            server.Start();

            while (true)
            {
                TcpClient client = server.AcceptTcpClient();
                NetworkStream ns = client.GetStream();

                string document = @"<!DOCTYPE html>
<html>
  <head>
    <title>Powered By Paketo Buildpacks</title>
  </head>
  <body>
    <img style=""display: block; margin-left: auto; margin-right: auto; width: 50%;"" src=""https://paketo.io/images/paketo-logo-full-color.png""></img>
  </body>
</html>";
                string payload = @"HTTP/1.1 200 OK
Accept-Ranges: bytes
Content-Length: " + Encoding.UTF8.GetByteCount(document) + @"
Connection: close
Content-Type: text/html; charset=utf-8

" + document;

                byte[] msg = new byte[System.Text.ASCIIEncoding.Unicode.GetByteCount(payload)];
                msg = Encoding.Default.GetBytes(payload);
                ns.Write(msg, 0, msg.Length);

                client.Close();
            }
        }
    }
}