Python實現簡易web伺服器

1、請自行了解 HTTP協議

2、創建Socket服務，監聽指定IP和埠

3、以阻塞方式等待客戶端連接

4、讀取客戶端請求數據並進行解析

5、準備伺服器運行上下文

6、處理客戶端請求數據

7、根據用戶請求路徑讀取文件

8、返迴響應結果給客戶端

9、程序入口

10、目錄結構

11、運行

python wsgiserver.py app:run

12、源碼

a.wsgiserver.py文件

#encoding:utf-8import socketimport StringIOimport sysimport loggingfrom datetime import datetimelogger = logging.getLogger(__name__)class WSGIServer(object): address_family = socket.AF_INET socket_type = socket.SOCK_STREAM request_queue_size = 30 recv_size = 1024 def __init__(self, server_address): self._listen_socket = _listen_socket = socket.socket(self.address_family, self.socket_type) _listen_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR,1) _listen_socket.bind(server_address) _listen_socket.listen(self.request_queue_size) _host, _port = _listen_socket.getsockname() self._server_name = socket.getfqdn(_host) self._server_port = _port self._headers_set = [] self._application = None self._client = None self._request_data = None self._request_method = None self._path = None self._request_version = None self._start_response = None def set_application(self, application): self._application = application def server_forever(self): _listen_socket = self._listen_socket logger.info(listen on %s:%s, self._server_name, self._server_port) while 1: try: self._client, _addr = _listen_socket.accept() self._handle_request(_addr) except KeyboardInterrupt as e: logger.info(interrupt) break except BaseException as e: logger.error(e) def _handle_request(self, client_addr): self._request_data = _request_data = self._client.recv(self.recv_size) self._parse_request_data(_request_data) _env = self._get_environment(client_addr) _result = self._application(_env, self.start_response) self._finish_response(_result) def _parse_request_data(self, request_data): _request_line = str(request_data.splitlines()[0]).rstrip(
) (self._request_method, self._path, self._request_version) = _request_line.split() def _get_environment(self, client_addr): _env = {} _env[wsgi.version] = (1, 0) _env[wsgi.url_scheme] = http _env[wsgi.input] = StringIO.StringIO(self._request_data) _env[wsgi.errors] = sys.stderr _env[wsgi.multithread] = False _env[wsgi.multiprocess] = False _env[wsgi.run_once] = False _env[REQUEST_METHOD] = self._request_method.upper() _env[PATH_INFO] = self._path _env[SERVER_NAME] = self._server_name _env[SERVER_PORT] = self._server_port _env[HTTP_CLIENT_IP] = client_addr[0] logger.info(%s %s %s %s, _env[HTTP_CLIENT_IP], datetime.now().strftime(%Y-%m-%d %H:%M:%S), _env[REQUEST_METHOD], _env[PATH_INFO]) return _env def start_response(self, status, response_headers, exc_info=None): _server_headers = [ (Date, Sun, 7 Jun 2015 23:07:04 GMT), (Server, WSGIServer 0.1) ] self._headers_set = [status, response_headers + _server_headers] def _finish_response(self, result): _status, _response_headers = self._headers_set _response = HTTP/1.1 {status}
.format(status=_status) for _header in _response_headers: _response += {0}:{1}
.format(*_header) _response +=
for _data in result: _response += _data self._client.sendall(_response) self._client.close()def make_server(server_address, application): server = WSGIServer(server_address) server.set_application(application) return server if __name__ == __main__: logging.basicConfig(level=logging.DEBUG) server_addr= (0.0.0.0, 43002) app_path = sys.argv[1] module, application = app_path.split(:) module = __import__(module) application = getattr(module, application) httpd = make_server(server_addr, application) httpd.server_forever()

b.app.py文件

#encoding:utf-8import osclass PageNotFoundException(BaseException): passdef render(filename, dirname=html): _path = os.path.join(dirname, filename) if os.path.exists(_path): with open(_path, rb) as handler: return handler.read() raise PageNotFoundException(file not found:%s % _path) def run(env, start_response): _path = env.get(PATH_INFO) response = try: _path = index.html if _path == / else _path[1:] if _path.endswith(.css): start_response(200 OK, [(Content-Type, text/css)]) elif _path.endswith(.js): start_response(200 OK, [(Content-Type, text/javascript)] elif _path.endswith(.html): start_response(200 OK, [(Content-Type, text/html)]) else: start_response(200 OK, [(Content-Type, text/plain), (Content-Disposition, attachment; filename=%s % os.path.basename(_path))]) response = render(_path) except PageNotFoundException as e: response = render(404.html) return [response,
]