Webserver Tricks

Webserver Tricks#

When the operator needs an HTTP listener and the box has no nginx, no Apache, no installed web framework, a rudimentary webserver written in whatever interpreter is on hand will do. The handbook collects one-shot servers across AWK, Go, JavaScript, Perl, PHP, Python, and a plain UNIX shell loop.

AWK#

#!/usr/bin/gawk -f
BEGIN {
    RS = ORS = "\r\n"
    HttpService = "/inet/tcp/8080/0/0"
    Hello = "<HTML><HEAD>" \
            "<TITLE>A Famous Greeting</TITLE></HEAD>" \
            "<BODY><H1>Hello, world</H1></BODY></HTML>"
    Len = length(Hello) + length(ORS)
    print "HTTP/1.0 200 OK"        |& HttpService
    print "Content-Length: " Len ORS |& HttpService
    print Hello                    |& HttpService
    while ((HttpService |& getline) > 0)
        continue;
    close(HttpService)
}

Go#

package main

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

func main() {
  http.HandleFunc("/", func(w http.ResponseWriter, req *http.Request) {
     fmt.Fprintln(w, "Goodbye, World!")
  })
  log.Fatal(http.ListenAndServe(":8080", nil))
}

JavaScript#

Node.js.

var http = require('http');
http.createServer(function (req, res) {
    res.writeHead(200, {'Content-Type': 'text/plain'});
    res.end('Goodbye, World!\n');
}).listen(8080, '127.0.0.1');

Perl#

use Socket;
my $port = 8080;
my $protocol = getprotobyname("tcp");
socket(SOCK, PF_INET, SOCK_STREAM, $protocol) or die "couldn't open a socket: $!";
setsockopt(SOCK, SOL_SOCKET, SO_REUSEADDR, 1) or die "couldn't set socket options: $!";
bind(SOCK, sockaddr_in($port, INADDR_ANY)) or die "couldn't bind socket to port $port: $!";
listen(SOCK, SOMAXCONN) or die "couldn't listen to port $port: $!";
while(accept(CLIENT, SOCK)){
  print CLIENT "HTTP/1.1 200 OK\r\n" .
               "Content-Type: text/html; charset=UTF-8\r\n\r\n" .
               "<html><head><title>Goodbye, world!</title></head><body>Goodbye, world!</body></html>\r\n";
  close CLIENT;
}

PHP#

<?php
$socket = socket_create(AF_INET, SOCK_STREAM, 0) or die('Failed to create socket!');
socket_bind($socket, 0, 8080);
socket_listen($socket);
$msg = '<html><head><title>Goodbye, world!</title></head><body>Goodbye, world!</body></html>';
for (;;) {
    if ($client = @socket_accept($socket)) {
        socket_write($client, "HTTP/1.1 200 OK\r\n" .
            "Content-length: " . strlen($msg) . "\r\n" .
            "Content-Type: text/html; charset=UTF-8\r\n\r\n" .
            $msg);
    } else usleep(100000);
}
?>

Python#

Python under 3.2 with wsgiref.simple_server.

from wsgiref.simple_server import make_server

def app(environ, start_response):
    start_response('200 OK', [('Content-Type','text/html')])
    yield b"<h1>Goodbye, World!</h1>"

server = make_server('127.0.0.1', 8080, app)
server.serve_forever()

Python 3 with http.server.

import threading
from http.server import BaseHTTPRequestHandler, ThreadingHTTPServer

class HelloHTTPRequestHandler(BaseHTTPRequestHandler):
  message = 'Hello World!'

  def do_GET(self):
    self.send_response(200)
    self.send_header('Content-type', 'text/html; charset=UTF-8')
    self.end_headers()
    self.wfile.write(self.message.encode('utf-8'))
    self.close_connection = True

def serve(addr, port):
  with ThreadingHTTPServer((addr, port), HelloHTTPRequestHandler) as server:
    server.serve_forever(poll_interval=None)

if __name__ == '__main__':
  addr, port = ('localhost', 80)
  threading.Thread(target=serve, args=(addr, port), daemon=True).start()

UNIX shell#

$ while true; do { echo -e 'HTTP/1.1 200 OK\r\n'; echo 'Hello, World!'; } | nc -l 8080; done

References#

Contents