基于python创建一个简单的HTTP-WEB服务器

• 背景

大多数情况下主机资源只有开发和测试相关人员可以登录直接操作，且有些特定情况“答辩、演示、远程”等这些场景下是无法直接登录主机的。web是所有终端用户都可以访问了，解决了人员权限与特定场景带来的问题。那么我们就来看看最简单的web服务器是怎么创建的~~

• 具体实现

首先搭建python环境，涉及问题请移步http://www.cnblogs.com/xnchll/p/6431664.html。python内建模块SimpleHTTPServer，源码如下路径是/usr/lib64/python2.6/SimpleHTTPServer.py，有兴趣可看看

 """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 cgi
 import sys
 import shutil
 import mimetypes
 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()
         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):
         """Common code for GET and HEAD commands.

         This sends the response code and MIME headers.

         Return value is either a file object (which has to be copied
         to the outputfile by the caller unless the command was HEAD,
         and must be closed by the caller under all circumstances), or
         None, in which case the caller has nothing further to do.

         """
         path = self.translate_path(self.path)
         f = None
         if os.path.isdir(path):
             if not self.path.endswith('/'):
                 # redirect browser - doing basically what apache does
                 self.send_response(301)
                 self.send_header("Location", self.path + "/")
                 self.end_headers()
                 return None
             for index in "index.html", "index.htm":
                 index = os.path.join(path, index)
                 if os.path.exists(index):
                     path = index
                     break
             else:
                 return self.list_directory(path)
         ctype = self.guess_type(path)
         try:
             # Always read in binary mode. Opening files in text mode may cause
             # newline translations, making the actual size of the content
             # transmitted *less* than the content-length!
             f = open(path, 'rb')
         except IOError:
             self.send_error(404, "File not found")
             return None
         self.send_response(200)
         self.send_header("Content-type", ctype)
         fs = os.fstat(f.fileno())
         self.send_header("Content-Length", str(fs[6]))
         self.send_header("Last-Modified", self.date_time_string(fs.st_mtime))
         self.end_headers()
         return f

     def list_directory(self, path):
         """Helper to produce a directory listing (absent index.html).

         Return value is either a file object, or None (indicating an
         error).  In either case, the headers are sent, making the
         interface the same as for send_head().

         """
         try:
             list = os.listdir(path)
         except os.error:
             self.send_error(404, "No permission to list directory")
             return None
         list.sort(key=lambda a: a.lower())
         f = StringIO()
         displaypath = cgi.escape(urllib.unquote(self.path))
         f.write('<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">')
         f.write("<html>\n<title>creditAutoTest project  %s</title>\n" % displaypath)
         f.write("<body>\n<h2>Directory listing for %s</h2>\n" % displaypath)
         f.write("<hr>\n<ul>\n")
         for name in list:
             fullname = os.path.join(path, name)
             displayname = linkname = name
             # Append / for directories or @ for symbolic links
             if os.path.isdir(fullname):
                 displayname = name + "/"
                 linkname = name + "/"
             if os.path.islink(fullname):
                 displayname = name + "@"
                 # Note: a link to a directory displays with @ and links with /
             f.write('<li><a href="%s">%s</a>\n'
                     % (urllib.quote(linkname), cgi.escape(displayname)))
         f.write("</ul>\n<hr>\n</body>\n</html>\n")
         length = f.tell()
         f.seek(0)
         self.send_response(200)
         encoding = sys.getfilesystemencoding()
         self.send_header("Content-type", "text/html; charset=%s" % encoding)
         self.send_header("Content-Length", str(length))
         self.end_headers()
         return f

     def translate_path(self, path):
         """Translate a /-separated PATH to the local filename syntax.

         Components that mean special things to the local file system
         (e.g. drive or directory names) are ignored.  (XXX They should
         probably be diagnosed.)

         """
         # abandon query parameters
         path = path.split('?',1)[0]
         path = path.split('#',1)[0]
         path = posixpath.normpath(urllib.unquote(path))
         words = path.split('/')
         words = filter(None, words)
         path = os.getcwd()
         for word in words:
             drive, word = os.path.splitdrive(word)
             head, word = os.path.split(word)
             if word in (os.curdir, os.pardir): continue
             path = os.path.join(path, word)
         return path

     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 guess_type(self, path):
         """Guess the type of a file.

         Argument is a PATH (a filename).

         Return value is a string of the form type/subtype,
         usable for a MIME Content-type header.

         The default implementation looks the file's extension
         up in the table self.extensions_map, using application/octet-stream
         as a default; however it would be permissible (if
         slow) to look inside the data to make a better guess.

         """

         base, ext = posixpath.splitext(path)
         if ext in self.extensions_map:
             return self.extensions_map[ext]
         ext = ext.lower()
         if ext in self.extensions_map:
             return self.extensions_map[ext]
         else:
             return self.extensions_map['']

     if not mimetypes.inited:
         mimetypes.init() # try to read system mime.types
     extensions_map = mimetypes.types_map.copy()
     extensions_map.update({
         '': 'application/octet-stream', # Default
         '.py': 'text/plain',
         '.c': 'text/plain',
         '.h': 'text/plain',
         '.log':'text/plain',
         '.out':'text/plain',
         '.sql':'text/plain',
         '.conf':'text/plain'
         })

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

 if __name__ == '__main__':
     test()

使用方式如下：

1. 明确需要展示web的根目录，比如/user/src
2. 了解SimpleHTTPServer模块的几个关键参数，只说一下web服务的启动端口port。比如python -m SimpleHTTPServer port
3. 修改一下源码web说明和支撑多种文件格式等等：

最后，启动web服务器：

python -m SimpleHTTPServer 8009

小建议，一般web服务都是常驻进程，这里建议也设置为常驻进程或者添加为linux系统服务。

• 结果展示：