Implementing a Simple Web Server to Run Scripts

Overview

Sometimes it is convenient to create a simple web server front-end to initiate the running of scripts via a web interface. The following is an example of a simple one based on SimpleHTTPModule...

This code makes use of the commands module (See Running Command-line Scripts in Python) to fire off a Python script which actually does the work - in this case a set of test ODBC accesses to an MS SqlServer database.

#!/usr/bin/env python

"""Simple HTTP Server.

This module builds on BaseHTTPServer by implementing the standard GET
and HEAD requests in a fairly straightforward manner.

"""


__version__ = "0.6"

__all__ = ["SimpleHTTPRequestHandler"]

import os
import posixpath
import BaseHTTPServer
import urllib
import urlparse
import cgi
import shutil
import mimetypes
import commands

try:
    from cStringIO import StringIO
except ImportError:
    from StringIO import StringIO


class SimpleHTTPRequestHandler(BaseHTTPServer.BaseHTTPRequestHandler):

    """Simple HTTP request handler with GET and HEAD commands.

    This serves files from the current directory and any of its
    subdirectories.  The MIME type for files is determined by
    calling the .guess_type() method.

    The GET and HEAD requests are identical except that the HEAD
    request omits the actual contents of the file.

    """

    server_version = "SimpleHTTP/" + __version__

    def do_GET(self):
        """Serve a GET request."""
        #f = self.send_head()
        f = self.do_test()
        if f:
            self.copyfile(f, self.wfile)
            f.close()

    def do_HEAD(self):
        """Serve a HEAD request."""
        f = self.send_head()
        if f:
            f.close()

    def send_head(self):
        pass

    def do_test(self):
        f = StringIO()
        f.write("<title>Test</title>\n")
        f.write("<h2>test</h2>\n")
        f.write("<hr>\n")

        (status, output) = commands.getstatusoutput("./test.py")

        lines = output.split('\n')

        for line in lines:
            f.write("%s<br>\n" % line)

        f.write("<hr>\n")
        length = f.tell()
        f.seek(0)

        self.send_response(200)
        self.send_header("Content-type", "text/html")
        self.send_header("Content-Length", str(length))
        self.end_headers()
        return f

    def copyfile(self, source, outputfile):
        """Copy all data between two file objects.

        The SOURCE argument is a file object open for reading
        (or anything with a read() method) and the DESTINATION
        argument is a file object open for writing (or
        anything with a write() method).

        The only reason for overriding this would be to change
        the block size or perhaps to replace newlines by CRLF
        -- note however that this the default server uses this
        to copy binary data as well.

        """
        shutil.copyfileobj(source, outputfile)

def test(HandlerClass = SimpleHTTPRequestHandler,
         ServerClass = BaseHTTPServer.HTTPServer):
    BaseHTTPServer.test(HandlerClass, ServerClass)

if __name__ == '__main__':
   test()

This code is a cut down version of the standard SimpleHTTPServer module from the 2.5.1 Python distribution (off cygwin) - found in /usr/lib/python2.5 directory.