Merge flask framework and other stuff from master

1 files changed, 1074 insertions, 0 deletions

diff --git a/python/werkzeug/serving.py b/python/werkzeug/serving.py
new file mode 100644
index 0000000..ff9f880
--- /dev/null
+++ b/python/werkzeug/serving.py
@@ -0,0 +1,1074 @@
+# -*- coding: utf-8 -*-
+"""
+    werkzeug.serving
+    ~~~~~~~~~~~~~~~~
+
+    There are many ways to serve a WSGI application.  While you're developing
+    it you usually don't want a full blown webserver like Apache but a simple
+    standalone one.  From Python 2.5 onwards there is the `wsgiref`_ server in
+    the standard library.  If you're using older versions of Python you can
+    download the package from the cheeseshop.
+
+    However there are some caveats. Sourcecode won't reload itself when
+    changed and each time you kill the server using ``^C`` you get an
+    `KeyboardInterrupt` error.  While the latter is easy to solve the first
+    one can be a pain in the ass in some situations.
+
+    The easiest way is creating a small ``start-myproject.py`` that runs the
+    application::
+
+        #!/usr/bin/env python
+        # -*- coding: utf-8 -*-
+        from myproject import make_app
+        from werkzeug.serving import run_simple
+
+        app = make_app(...)
+        run_simple('localhost', 8080, app, use_reloader=True)
+
+    You can also pass it a `extra_files` keyword argument with a list of
+    additional files (like configuration files) you want to observe.
+
+    For bigger applications you should consider using `click`
+    (http://click.pocoo.org) instead of a simple start file.
+
+
+    :copyright: 2007 Pallets
+    :license: BSD-3-Clause
+"""
+import io
+import os
+import signal
+import socket
+import sys
+
+import werkzeug
+from ._compat import PY2
+from ._compat import reraise
+from ._compat import WIN
+from ._compat import wsgi_encoding_dance
+from ._internal import _log
+from .exceptions import InternalServerError
+from .urls import uri_to_iri
+from .urls import url_parse
+from .urls import url_unquote
+
+try:
+    import socketserver
+    from http.server import BaseHTTPRequestHandler
+    from http.server import HTTPServer
+except ImportError:
+    import SocketServer as socketserver
+    from BaseHTTPServer import HTTPServer
+    from BaseHTTPServer import BaseHTTPRequestHandler
+
+try:
+    import ssl
+except ImportError:
+
+    class _SslDummy(object):
+        def __getattr__(self, name):
+            raise RuntimeError("SSL support unavailable")
+
+    ssl = _SslDummy()
+
+try:
+    import termcolor
+except ImportError:
+    termcolor = None
+
+
+def _get_openssl_crypto_module():
+    try:
+        from OpenSSL import crypto
+    except ImportError:
+        raise TypeError("Using ad-hoc certificates requires the pyOpenSSL library.")
+    else:
+        return crypto
+
+
+ThreadingMixIn = socketserver.ThreadingMixIn
+can_fork = hasattr(os, "fork")
+
+if can_fork:
+    ForkingMixIn = socketserver.ForkingMixIn
+else:
+
+    class ForkingMixIn(object):
+        pass
+
+
+try:
+    af_unix = socket.AF_UNIX
+except AttributeError:
+    af_unix = None
+
+
+LISTEN_QUEUE = 128
+can_open_by_fd = not WIN and hasattr(socket, "fromfd")
+
+# On Python 3, ConnectionError represents the same errnos as
+# socket.error from Python 2, while socket.error is an alias for the
+# more generic OSError.
+if PY2:
+    _ConnectionError = socket.error
+else:
+    _ConnectionError = ConnectionError
+
+
+class DechunkedInput(io.RawIOBase):
+    """An input stream that handles Transfer-Encoding 'chunked'"""
+
+    def __init__(self, rfile):
+        self._rfile = rfile
+        self._done = False
+        self._len = 0
+
+    def readable(self):
+        return True
+
+    def read_chunk_len(self):
+        try:
+            line = self._rfile.readline().decode("latin1")
+            _len = int(line.strip(), 16)
+        except ValueError:
+            raise IOError("Invalid chunk header")
+        if _len < 0:
+            raise IOError("Negative chunk length not allowed")
+        return _len
+
+    def readinto(self, buf):
+        read = 0
+        while not self._done and read < len(buf):
+            if self._len == 0:
+                # This is the first chunk or we fully consumed the previous
+                # one. Read the next length of the next chunk
+                self._len = self.read_chunk_len()
+
+            if self._len == 0:
+                # Found the final chunk of size 0. The stream is now exhausted,
+                # but there is still a final newline that should be consumed
+                self._done = True
+
+            if self._len > 0:
+                # There is data (left) in this chunk, so append it to the
+                # buffer. If this operation fully consumes the chunk, this will
+                # reset self._len to 0.
+                n = min(len(buf), self._len)
+                buf[read : read + n] = self._rfile.read(n)
+                self._len -= n
+                read += n
+
+            if self._len == 0:
+                # Skip the terminating newline of a chunk that has been fully
+                # consumed. This also applies to the 0-sized final chunk
+                terminator = self._rfile.readline()
+                if terminator not in (b"\n", b"\r\n", b"\r"):
+                    raise IOError("Missing chunk terminating newline")
+
+        return read
+
+
+class WSGIRequestHandler(BaseHTTPRequestHandler, object):
+
+    """A request handler that implements WSGI dispatching."""
+
+    @property
+    def server_version(self):
+        return "Werkzeug/" + werkzeug.__version__
+
+    def make_environ(self):
+        request_url = url_parse(self.path)
+
+        def shutdown_server():
+            self.server.shutdown_signal = True
+
+        url_scheme = "http" if self.server.ssl_context is None else "https"
+        if not self.client_address:
+            self.client_address = "<local>"
+        if isinstance(self.client_address, str):
+            self.client_address = (self.client_address, 0)
+        else:
+            pass
+        path_info = url_unquote(request_url.path)
+
+        environ = {
+            "wsgi.version": (1, 0),
+            "wsgi.url_scheme": url_scheme,
+            "wsgi.input": self.rfile,
+            "wsgi.errors": sys.stderr,
+            "wsgi.multithread": self.server.multithread,
+            "wsgi.multiprocess": self.server.multiprocess,
+            "wsgi.run_once": False,
+            "werkzeug.server.shutdown": shutdown_server,
+            "SERVER_SOFTWARE": self.server_version,
+            "REQUEST_METHOD": self.command,
+            "SCRIPT_NAME": "",
+            "PATH_INFO": wsgi_encoding_dance(path_info),
+            "QUERY_STRING": wsgi_encoding_dance(request_url.query),
+            # Non-standard, added by mod_wsgi, uWSGI
+            "REQUEST_URI": wsgi_encoding_dance(self.path),
+            # Non-standard, added by gunicorn
+            "RAW_URI": wsgi_encoding_dance(self.path),
+            "REMOTE_ADDR": self.address_string(),
+            "REMOTE_PORT": self.port_integer(),
+            "SERVER_NAME": self.server.server_address[0],
+            "SERVER_PORT": str(self.server.server_address[1]),
+            "SERVER_PROTOCOL": self.request_version,
+        }
+
+        for key, value in self.get_header_items():
+            key = key.upper().replace("-", "_")
+            value = value.replace("\r\n", "")
+            if key not in ("CONTENT_TYPE", "CONTENT_LENGTH"):
+                key = "HTTP_" + key
+                if key in environ:
+                    value = "{},{}".format(environ[key], value)
+            environ[key] = value
+
+        if environ.get("HTTP_TRANSFER_ENCODING", "").strip().lower() == "chunked":
+            environ["wsgi.input_terminated"] = True
+            environ["wsgi.input"] = DechunkedInput(environ["wsgi.input"])
+
+        if request_url.scheme and request_url.netloc:
+            environ["HTTP_HOST"] = request_url.netloc
+
+        return environ
+
+    def run_wsgi(self):
+        if self.headers.get("Expect", "").lower().strip() == "100-continue":
+            self.wfile.write(b"HTTP/1.1 100 Continue\r\n\r\n")
+
+        self.environ = environ = self.make_environ()
+        headers_set = []
+        headers_sent = []
+
+        def write(data):
+            assert headers_set, "write() before start_response"
+            if not headers_sent:
+                status, response_headers = headers_sent[:] = headers_set
+                try:
+                    code, msg = status.split(None, 1)
+                except ValueError:
+                    code, msg = status, ""
+                code = int(code)
+                self.send_response(code, msg)
+                header_keys = set()
+                for key, value in response_headers:
+                    self.send_header(key, value)
+                    key = key.lower()
+                    header_keys.add(key)
+                if not (
+                    "content-length" in header_keys
+                    or environ["REQUEST_METHOD"] == "HEAD"
+                    or code < 200
+                    or code in (204, 304)
+                ):
+                    self.close_connection = True
+                    self.send_header("Connection", "close")
+                if "server" not in header_keys:
+                    self.send_header("Server", self.version_string())
+                if "date" not in header_keys:
+                    self.send_header("Date", self.date_time_string())
+                self.end_headers()
+
+            assert isinstance(data, bytes), "applications must write bytes"
+            self.wfile.write(data)
+            self.wfile.flush()
+
+        def start_response(status, response_headers, exc_info=None):
+            if exc_info:
+                try:
+                    if headers_sent:
+                        reraise(*exc_info)
+                finally:
+                    exc_info = None
+            elif headers_set:
+                raise AssertionError("Headers already set")
+            headers_set[:] = [status, response_headers]
+            return write
+
+        def execute(app):
+            application_iter = app(environ, start_response)
+            try:
+                for data in application_iter:
+                    write(data)
+                if not headers_sent:
+                    write(b"")
+            finally:
+                if hasattr(application_iter, "close"):
+                    application_iter.close()
+                application_iter = None
+
+        try:
+            execute(self.server.app)
+        except (_ConnectionError, socket.timeout) as e:
+            self.connection_dropped(e, environ)
+        except Exception:
+            if self.server.passthrough_errors:
+                raise
+            from .debug.tbtools import get_current_traceback
+
+            traceback = get_current_traceback(ignore_system_exceptions=True)
+            try:
+                # if we haven't yet sent the headers but they are set
+                # we roll back to be able to set them again.
+                if not headers_sent:
+                    del headers_set[:]
+                execute(InternalServerError())
+            except Exception:
+                pass
+            self.server.log("error", "Error on request:\n%s", traceback.plaintext)
+
+    def handle(self):
+        """Handles a request ignoring dropped connections."""
+        rv = None
+        try:
+            rv = BaseHTTPRequestHandler.handle(self)
+        except (_ConnectionError, socket.timeout) as e:
+            self.connection_dropped(e)
+        except Exception as e:
+            if self.server.ssl_context is None or not is_ssl_error(e):
+                raise
+        if self.server.shutdown_signal:
+            self.initiate_shutdown()
+        return rv
+
+    def initiate_shutdown(self):
+        """A horrible, horrible way to kill the server for Python 2.6 and
+        later.  It's the best we can do.
+        """
+        # Windows does not provide SIGKILL, go with SIGTERM then.
+        sig = getattr(signal, "SIGKILL", signal.SIGTERM)
+        # reloader active
+        if is_running_from_reloader():
+            os.kill(os.getpid(), sig)
+        # python 2.7
+        self.server._BaseServer__shutdown_request = True
+        # python 2.6
+        self.server._BaseServer__serving = False
+
+    def connection_dropped(self, error, environ=None):
+        """Called if the connection was closed by the client.  By default
+        nothing happens.
+        """
+
+    def handle_one_request(self):
+        """Handle a single HTTP request."""
+        self.raw_requestline = self.rfile.readline()
+        if not self.raw_requestline:
+            self.close_connection = 1
+        elif self.parse_request():
+            return self.run_wsgi()
+
+    def send_response(self, code, message=None):
+        """Send the response header and log the response code."""
+        self.log_request(code)
+        if message is None:
+            message = code in self.responses and self.responses[code][0] or ""
+        if self.request_version != "HTTP/0.9":
+            hdr = "%s %d %s\r\n" % (self.protocol_version, code, message)
+            self.wfile.write(hdr.encode("ascii"))
+
+    def version_string(self):
+        return BaseHTTPRequestHandler.version_string(self).strip()
+
+    def address_string(self):
+        if getattr(self, "environ", None):
+            return self.environ["REMOTE_ADDR"]
+        elif not self.client_address:
+            return "<local>"
+        elif isinstance(self.client_address, str):
+            return self.client_address
+        else:
+            return self.client_address[0]
+
+    def port_integer(self):
+        return self.client_address[1]
+
+    def log_request(self, code="-", size="-"):
+        try:
+            path = uri_to_iri(self.path)
+            msg = "%s %s %s" % (self.command, path, self.request_version)
+        except AttributeError:
+            # path isn't set if the requestline was bad
+            msg = self.requestline
+
+        code = str(code)
+
+        if termcolor:
+            color = termcolor.colored
+
+            if code[0] == "1":  # 1xx - Informational
+                msg = color(msg, attrs=["bold"])
+            elif code[0] == "2":  # 2xx - Success
+                msg = color(msg, color="white")
+            elif code == "304":  # 304 - Resource Not Modified
+                msg = color(msg, color="cyan")
+            elif code[0] == "3":  # 3xx - Redirection
+                msg = color(msg, color="green")
+            elif code == "404":  # 404 - Resource Not Found
+                msg = color(msg, color="yellow")
+            elif code[0] == "4":  # 4xx - Client Error
+                msg = color(msg, color="red", attrs=["bold"])
+            else:  # 5xx, or any other response
+                msg = color(msg, color="magenta", attrs=["bold"])
+
+        self.log("info", '"%s" %s %s', msg, code, size)
+
+    def log_error(self, *args):
+        self.log("error", *args)
+
+    def log_message(self, format, *args):
+        self.log("info", format, *args)
+
+    def log(self, type, message, *args):
+        _log(
+            type,
+            "%s - - [%s] %s\n"
+            % (self.address_string(), self.log_date_time_string(), message % args),
+        )
+
+    def get_header_items(self):
+        """
+        Get an iterable list of key/value pairs representing headers.
+
+        This function provides Python 2/3 compatibility as related to the
+        parsing of request headers. Python 2.7 is not compliant with
+        RFC 3875 Section 4.1.18 which requires multiple values for headers
+        to be provided or RFC 2616 which allows for folding of multi-line
+        headers. This function will return a matching list regardless
+        of Python version. It can be removed once Python 2.7 support
+        is dropped.
+
+        :return: List of tuples containing header hey/value pairs
+        """
+        if PY2:
+            # For Python 2, process the headers manually according to
+            # W3C RFC 2616 Section 4.2.
+            items = []
+            for header in self.headers.headers:
+                # Remove "\r\n" from the header and split on ":" to get
+                # the field name and value.
+                try:
+                    key, value = header[0:-2].split(":", 1)
+                except ValueError:
+                    # If header could not be slit with : but starts with white
+                    # space and it follows an existing header, it's a folded
+                    # header.
+                    if header[0] in ("\t", " ") and items:
+                        # Pop off the last header
+                        key, value = items.pop()
+                        # Append the current header to the value of the last
+                        # header which will be placed back on the end of the
+                        # list
+                        value = value + header
+                    # Otherwise it's just a bad header and should error
+                    else:
+                        # Re-raise the value error
+                        raise
+
+                # Add the key and the value once stripped of leading
+                # white space. The specification allows for stripping
+                # trailing white space but the Python 3 code does not
+                # strip trailing white space. Therefore, trailing space
+                # will be left as is to match the Python 3 behavior.
+                items.append((key, value.lstrip()))
+        else:
+            items = self.headers.items()
+
+        return items
+
+
+#: backwards compatible name if someone is subclassing it
+BaseRequestHandler = WSGIRequestHandler
+
+
+def generate_adhoc_ssl_pair(cn=None):
+    from random import random
+
+    crypto = _get_openssl_crypto_module()
+
+    # pretty damn sure that this is not actually accepted by anyone
+    if cn is None:
+        cn = "*"
+
+    cert = crypto.X509()
+    cert.set_serial_number(int(random() * sys.maxsize))
+    cert.gmtime_adj_notBefore(0)
+    cert.gmtime_adj_notAfter(60 * 60 * 24 * 365)
+
+    subject = cert.get_subject()
+    subject.CN = cn
+    subject.O = "Dummy Certificate"  # noqa: E741
+
+    issuer = cert.get_issuer()
+    issuer.CN = subject.CN
+    issuer.O = subject.O  # noqa: E741
+
+    pkey = crypto.PKey()
+    pkey.generate_key(crypto.TYPE_RSA, 2048)
+    cert.set_pubkey(pkey)
+    cert.sign(pkey, "sha256")
+
+    return cert, pkey
+
+
+def make_ssl_devcert(base_path, host=None, cn=None):
+    """Creates an SSL key for development.  This should be used instead of
+    the ``'adhoc'`` key which generates a new cert on each server start.
+    It accepts a path for where it should store the key and cert and
+    either a host or CN.  If a host is given it will use the CN
+    ``*.host/CN=host``.
+
+    For more information see :func:`run_simple`.
+
+    .. versionadded:: 0.9
+
+    :param base_path: the path to the certificate and key.  The extension
+                      ``.crt`` is added for the certificate, ``.key`` is
+                      added for the key.
+    :param host: the name of the host.  This can be used as an alternative
+                 for the `cn`.
+    :param cn: the `CN` to use.
+    """
+    from OpenSSL import crypto
+
+    if host is not None:
+        cn = "*.%s/CN=%s" % (host, host)
+    cert, pkey = generate_adhoc_ssl_pair(cn=cn)
+
+    cert_file = base_path + ".crt"
+    pkey_file = base_path + ".key"
+
+    with open(cert_file, "wb") as f:
+        f.write(crypto.dump_certificate(crypto.FILETYPE_PEM, cert))
+    with open(pkey_file, "wb") as f:
+        f.write(crypto.dump_privatekey(crypto.FILETYPE_PEM, pkey))
+
+    return cert_file, pkey_file
+
+
+def generate_adhoc_ssl_context():
+    """Generates an adhoc SSL context for the development server."""
+    crypto = _get_openssl_crypto_module()
+    import tempfile
+    import atexit
+
+    cert, pkey = generate_adhoc_ssl_pair()
+    cert_handle, cert_file = tempfile.mkstemp()
+    pkey_handle, pkey_file = tempfile.mkstemp()
+    atexit.register(os.remove, pkey_file)
+    atexit.register(os.remove, cert_file)
+
+    os.write(cert_handle, crypto.dump_certificate(crypto.FILETYPE_PEM, cert))
+    os.write(pkey_handle, crypto.dump_privatekey(crypto.FILETYPE_PEM, pkey))
+    os.close(cert_handle)
+    os.close(pkey_handle)
+    ctx = load_ssl_context(cert_file, pkey_file)
+    return ctx
+
+
+def load_ssl_context(cert_file, pkey_file=None, protocol=None):
+    """Loads SSL context from cert/private key files and optional protocol.
+    Many parameters are directly taken from the API of
+    :py:class:`ssl.SSLContext`.
+
+    :param cert_file: Path of the certificate to use.
+    :param pkey_file: Path of the private key to use. If not given, the key
+                      will be obtained from the certificate file.
+    :param protocol: One of the ``PROTOCOL_*`` constants in the stdlib ``ssl``
+                     module. Defaults to ``PROTOCOL_SSLv23``.
+    """
+    if protocol is None:
+        protocol = ssl.PROTOCOL_SSLv23
+    ctx = _SSLContext(protocol)
+    ctx.load_cert_chain(cert_file, pkey_file)
+    return ctx
+
+
+class _SSLContext(object):
+
+    """A dummy class with a small subset of Python3's ``ssl.SSLContext``, only
+    intended to be used with and by Werkzeug."""
+
+    def __init__(self, protocol):
+        self._protocol = protocol
+        self._certfile = None
+        self._keyfile = None
+        self._password = None
+
+    def load_cert_chain(self, certfile, keyfile=None, password=None):
+        self._certfile = certfile
+        self._keyfile = keyfile or certfile
+        self._password = password
+
+    def wrap_socket(self, sock, **kwargs):
+        return ssl.wrap_socket(
+            sock,
+            keyfile=self._keyfile,
+            certfile=self._certfile,
+            ssl_version=self._protocol,
+            **kwargs
+        )
+
+
+def is_ssl_error(error=None):
+    """Checks if the given error (or the current one) is an SSL error."""
+    exc_types = (ssl.SSLError,)
+    try:
+        from OpenSSL.SSL import Error
+
+        exc_types += (Error,)
+    except ImportError:
+        pass
+
+    if error is None:
+        error = sys.exc_info()[1]
+    return isinstance(error, exc_types)
+
+
+def select_address_family(host, port):
+    """Return ``AF_INET4``, ``AF_INET6``, or ``AF_UNIX`` depending on
+    the host and port."""
+    # disabled due to problems with current ipv6 implementations
+    # and various operating systems.  Probably this code also is
+    # not supposed to work, but I can't come up with any other
+    # ways to implement this.
+    # try:
+    #     info = socket.getaddrinfo(host, port, socket.AF_UNSPEC,
+    #                               socket.SOCK_STREAM, 0,
+    #                               socket.AI_PASSIVE)
+    #     if info:
+    #         return info[0][0]
+    # except socket.gaierror:
+    #     pass
+    if host.startswith("unix://"):
+        return socket.AF_UNIX
+    elif ":" in host and hasattr(socket, "AF_INET6"):
+        return socket.AF_INET6
+    return socket.AF_INET
+
+
+def get_sockaddr(host, port, family):
+    """Return a fully qualified socket address that can be passed to
+    :func:`socket.bind`."""
+    if family == af_unix:
+        return host.split("://", 1)[1]
+    try:
+        res = socket.getaddrinfo(
+            host, port, family, socket.SOCK_STREAM, socket.IPPROTO_TCP
+        )
+    except socket.gaierror:
+        return host, port
+    return res[0][4]
+
+
+class BaseWSGIServer(HTTPServer, object):
+
+    """Simple single-threaded, single-process WSGI server."""
+
+    multithread = False
+    multiprocess = False
+    request_queue_size = LISTEN_QUEUE
+
+    def __init__(
+        self,
+        host,
+        port,
+        app,
+        handler=None,
+        passthrough_errors=False,
+        ssl_context=None,
+        fd=None,
+    ):
+        if handler is None:
+            handler = WSGIRequestHandler
+
+        self.address_family = select_address_family(host, port)
+
+        if fd is not None:
+            real_sock = socket.fromfd(fd, self.address_family, socket.SOCK_STREAM)
+            port = 0
+
+        server_address = get_sockaddr(host, int(port), self.address_family)
+
+        # remove socket file if it already exists
+        if self.address_family == af_unix and os.path.exists(server_address):
+            os.unlink(server_address)
+        HTTPServer.__init__(self, server_address, handler)
+
+        self.app = app
+        self.passthrough_errors = passthrough_errors
+        self.shutdown_signal = False
+        self.host = host
+        self.port = self.socket.getsockname()[1]
+
+        # Patch in the original socket.
+        if fd is not None:
+            self.socket.close()
+            self.socket = real_sock
+            self.server_address = self.socket.getsockname()
+
+        if ssl_context is not None:
+            if isinstance(ssl_context, tuple):
+                ssl_context = load_ssl_context(*ssl_context)
+            if ssl_context == "adhoc":
+                ssl_context = generate_adhoc_ssl_context()
+            # If we are on Python 2 the return value from socket.fromfd
+            # is an internal socket object but what we need for ssl wrap
+            # is the wrapper around it :(
+            sock = self.socket
+            if PY2 and not isinstance(sock, socket.socket):
+                sock = socket.socket(sock.family, sock.type, sock.proto, sock)
+            self.socket = ssl_context.wrap_socket(sock, server_side=True)
+            self.ssl_context = ssl_context
+        else:
+            self.ssl_context = None
+
+    def log(self, type, message, *args):
+        _log(type, message, *args)
+
+    def serve_forever(self):
+        self.shutdown_signal = False
+        try:
+            HTTPServer.serve_forever(self)
+        except KeyboardInterrupt:
+            pass
+        finally:
+            self.server_close()
+
+    def handle_error(self, request, client_address):
+        if self.passthrough_errors:
+            raise
+        # Python 2 still causes a socket.error after the earlier
+        # handling, so silence it here.
+        if isinstance(sys.exc_info()[1], _ConnectionError):
+            return
+        return HTTPServer.handle_error(self, request, client_address)
+
+    def get_request(self):
+        con, info = self.socket.accept()
+        return con, info
+
+
+class ThreadedWSGIServer(ThreadingMixIn, BaseWSGIServer):
+
+    """A WSGI server that does threading."""
+
+    multithread = True
+    daemon_threads = True
+
+
+class ForkingWSGIServer(ForkingMixIn, BaseWSGIServer):
+
+    """A WSGI server that does forking."""
+
+    multiprocess = True
+
+    def __init__(
+        self,
+        host,
+        port,
+        app,
+        processes=40,
+        handler=None,
+        passthrough_errors=False,
+        ssl_context=None,
+        fd=None,
+    ):
+        if not can_fork:
+            raise ValueError("Your platform does not support forking.")
+        BaseWSGIServer.__init__(
+            self, host, port, app, handler, passthrough_errors, ssl_context, fd
+        )
+        self.max_children = processes
+
+
+def make_server(
+    host=None,
+    port=None,
+    app=None,
+    threaded=False,
+    processes=1,
+    request_handler=None,
+    passthrough_errors=False,
+    ssl_context=None,
+    fd=None,
+):
+    """Create a new server instance that is either threaded, or forks
+    or just processes one request after another.
+    """
+    if threaded and processes > 1:
+        raise ValueError("cannot have a multithreaded and multi process server.")
+    elif threaded:
+        return ThreadedWSGIServer(
+            host, port, app, request_handler, passthrough_errors, ssl_context, fd=fd
+        )
+    elif processes > 1:
+        return ForkingWSGIServer(
+            host,
+            port,
+            app,
+            processes,
+            request_handler,
+            passthrough_errors,
+            ssl_context,
+            fd=fd,
+        )
+    else:
+        return BaseWSGIServer(
+            host, port, app, request_handler, passthrough_errors, ssl_context, fd=fd
+        )
+
+
+def is_running_from_reloader():
+    """Checks if the application is running from within the Werkzeug
+    reloader subprocess.
+
+    .. versionadded:: 0.10
+    """
+    return os.environ.get("WERKZEUG_RUN_MAIN") == "true"
+
+
+def run_simple(
+    hostname,
+    port,
+    application,
+    use_reloader=False,
+    use_debugger=False,
+    use_evalex=True,
+    extra_files=None,
+    reloader_interval=1,
+    reloader_type="auto",
+    threaded=False,
+    processes=1,
+    request_handler=None,
+    static_files=None,
+    passthrough_errors=False,
+    ssl_context=None,
+):
+    """Start a WSGI application. Optional features include a reloader,
+    multithreading and fork support.
+
+    This function has a command-line interface too::
+
+        python -m werkzeug.serving --help
+
+    .. versionadded:: 0.5
+       `static_files` was added to simplify serving of static files as well
+       as `passthrough_errors`.
+
+    .. versionadded:: 0.6
+       support for SSL was added.
+
+    .. versionadded:: 0.8
+       Added support for automatically loading a SSL context from certificate
+       file and private key.
+
+    .. versionadded:: 0.9
+       Added command-line interface.
+
+    .. versionadded:: 0.10
+       Improved the reloader and added support for changing the backend
+       through the `reloader_type` parameter.  See :ref:`reloader`
+       for more information.
+
+    .. versionchanged:: 0.15
+        Bind to a Unix socket by passing a path that starts with
+        ``unix://`` as the ``hostname``.
+
+    :param hostname: The host to bind to, for example ``'localhost'``.
+        If the value is a path that starts with ``unix://`` it will bind
+        to a Unix socket instead of a TCP socket..
+    :param port: The port for the server.  eg: ``8080``
+    :param application: the WSGI application to execute
+    :param use_reloader: should the server automatically restart the python
+                         process if modules were changed?
+    :param use_debugger: should the werkzeug debugging system be used?
+    :param use_evalex: should the exception evaluation feature be enabled?
+    :param extra_files: a list of files the reloader should watch
+                        additionally to the modules.  For example configuration
+                        files.
+    :param reloader_interval: the interval for the reloader in seconds.
+    :param reloader_type: the type of reloader to use.  The default is
+                          auto detection.  Valid values are ``'stat'`` and
+                          ``'watchdog'``. See :ref:`reloader` for more
+                          information.
+    :param threaded: should the process handle each request in a separate
+                     thread?
+    :param processes: if greater than 1 then handle each request in a new process
+                      up to this maximum number of concurrent processes.
+    :param request_handler: optional parameter that can be used to replace
+                            the default one.  You can use this to replace it
+                            with a different
+                            :class:`~BaseHTTPServer.BaseHTTPRequestHandler`
+                            subclass.
+    :param static_files: a list or dict of paths for static files.  This works
+                         exactly like :class:`SharedDataMiddleware`, it's actually
+                         just wrapping the application in that middleware before
+                         serving.
+    :param passthrough_errors: set this to `True` to disable the error catching.
+                               This means that the server will die on errors but
+                               it can be useful to hook debuggers in (pdb etc.)
+    :param ssl_context: an SSL context for the connection. Either an
+                        :class:`ssl.SSLContext`, a tuple in the form
+                        ``(cert_file, pkey_file)``, the string ``'adhoc'`` if
+                        the server should automatically create one, or ``None``
+                        to disable SSL (which is the default).
+    """
+    if not isinstance(port, int):
+        raise TypeError("port must be an integer")
+    if use_debugger:
+        from .debug import DebuggedApplication
+
+        application = DebuggedApplication(application, use_evalex)
+    if static_files:
+        from .middleware.shared_data import SharedDataMiddleware
+
+        application = SharedDataMiddleware(application, static_files)
+
+    def log_startup(sock):
+        display_hostname = hostname if hostname not in ("", "*") else "localhost"
+        quit_msg = "(Press CTRL+C to quit)"
+        if sock.family == af_unix:
+            _log("info", " * Running on %s %s", display_hostname, quit_msg)
+        else:
+            if ":" in display_hostname:
+                display_hostname = "[%s]" % display_hostname
+            port = sock.getsockname()[1]
+            _log(
+                "info",
+                " * Running on %s://%s:%d/ %s",
+                "http" if ssl_context is None else "https",
+                display_hostname,
+                port,
+                quit_msg,
+            )
+
+    def inner():
+        try:
+            fd = int(os.environ["WERKZEUG_SERVER_FD"])
+        except (LookupError, ValueError):
+            fd = None
+        srv = make_server(
+            hostname,
+            port,
+            application,
+            threaded,
+            processes,
+            request_handler,
+            passthrough_errors,
+            ssl_context,
+            fd=fd,
+        )
+        if fd is None:
+            log_startup(srv.socket)
+        srv.serve_forever()
+
+    if use_reloader:
+        # If we're not running already in the subprocess that is the
+        # reloader we want to open up a socket early to make sure the
+        # port is actually available.
+        if not is_running_from_reloader():
+            if port == 0 and not can_open_by_fd:
+                raise ValueError(
+                    "Cannot bind to a random port with enabled "
+                    "reloader if the Python interpreter does "
+                    "not support socket opening by fd."
+                )
+
+            # Create and destroy a socket so that any exceptions are
+            # raised before we spawn a separate Python interpreter and
+            # lose this ability.
+            address_family = select_address_family(hostname, port)
+            server_address = get_sockaddr(hostname, port, address_family)
+            s = socket.socket(address_family, socket.SOCK_STREAM)
+            s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+            s.bind(server_address)
+            if hasattr(s, "set_inheritable"):
+                s.set_inheritable(True)
+
+            # If we can open the socket by file descriptor, then we can just
+            # reuse this one and our socket will survive the restarts.
+            if can_open_by_fd:
+                os.environ["WERKZEUG_SERVER_FD"] = str(s.fileno())
+                s.listen(LISTEN_QUEUE)
+                log_startup(s)
+            else:
+                s.close()
+                if address_family == af_unix:
+                    _log("info", "Unlinking %s" % server_address)
+                    os.unlink(server_address)
+
+        # Do not use relative imports, otherwise "python -m werkzeug.serving"
+        # breaks.
+        from ._reloader import run_with_reloader
+
+        run_with_reloader(inner, extra_files, reloader_interval, reloader_type)
+    else:
+        inner()
+
+
+def run_with_reloader(*args, **kwargs):
+    # People keep using undocumented APIs.  Do not use this function
+    # please, we do not guarantee that it continues working.
+    from ._reloader import run_with_reloader
+
+    return run_with_reloader(*args, **kwargs)
+
+
+def main():
+    """A simple command-line interface for :py:func:`run_simple`."""
+
+    # in contrast to argparse, this works at least under Python < 2.7
+    import optparse
+    from .utils import import_string
+
+    parser = optparse.OptionParser(usage="Usage: %prog [options] app_module:app_object")
+    parser.add_option(
+        "-b",
+        "--bind",
+        dest="address",
+        help="The hostname:port the app should listen on.",
+    )
+    parser.add_option(
+        "-d",
+        "--debug",
+        dest="use_debugger",
+        action="store_true",
+        default=False,
+        help="Use Werkzeug's debugger.",
+    )
+    parser.add_option(
+        "-r",
+        "--reload",
+        dest="use_reloader",
+        action="store_true",
+        default=False,
+        help="Reload Python process if modules change.",
+    )
+    options, args = parser.parse_args()
+
+    hostname, port = None, None
+    if options.address:
+        address = options.address.split(":")
+        hostname = address[0]
+        if len(address) > 1:
+            port = address[1]
+
+    if len(args) != 1:
+        sys.stdout.write("No application supplied, or too much. See --help\n")
+        sys.exit(1)
+    app = import_string(args[0])
+
+    run_simple(
+        hostname=(hostname or "127.0.0.1"),
+        port=int(port or 5000),
+        application=app,
+        use_reloader=options.use_reloader,
+        use_debugger=options.use_debugger,
+    )
+
+
+if __name__ == "__main__":
+    main()