_cpserver.py

"""Manage HTTP servers with CherryPy."""

import cherrypy
from cherrypy.lib.reprconf import attributes
from cherrypy._cpcompat import text_or_bytes
from cherrypy.process.servers import ServerAdapter


__all__ = ('Server', )


class Server(ServerAdapter):
    """An adapter for an HTTP server.

    You can set attributes (like socket_host and socket_port)
    on *this* object (which is probably cherrypy.server), and call
    quickstart. For example::

        cherrypy.server.socket_port = 80
        cherrypy.quickstart()
    """

    socket_port = 8080
    """The TCP port on which to listen for connections."""

    _socket_host = '127.0.0.1'

    @property
    def socket_host(self):  # noqa: D401; irrelevant for properties
        """The hostname or IP address on which to listen for connections.

        Host values may be any IPv4 or IPv6 address, or any valid hostname.
        The string 'localhost' is a synonym for '127.0.0.1' (or '::1', if
        your hosts file prefers IPv6). The string '0.0.0.0' is a special
        IPv4 entry meaning "any active interface" (INADDR_ANY), and '::'
        is the similar IN6ADDR_ANY for IPv6. The empty string or None are
        not allowed.
        """
        return self._socket_host

    @socket_host.setter
    def socket_host(self, value):
        if value == '':
            raise ValueError("The empty string ('') is not an allowed value. "
                             "Use '0.0.0.0' instead to listen on all active "
                             'interfaces (INADDR_ANY).')
        self._socket_host = value

    socket_file = None
    """If given, the name of the UNIX socket to use instead of TCP/IP.

    When this option is not None, the `socket_host` and `socket_port` options
    are ignored."""

    socket_queue_size = 5
    """The 'backlog' argument to socket.listen(); specifies the maximum number
    of queued connections (default 5)."""

    socket_timeout = 10
    """The timeout in seconds for accepted connections (default 10)."""

    accepted_queue_size = -1
    """The maximum number of requests which will be queued up before
    the server refuses to accept it (default -1, meaning no limit)."""

    accepted_queue_timeout = 10
    """The timeout in seconds for attempting to add a request to the
    queue when the queue is full (default 10)."""

    shutdown_timeout = 5
    """The time to wait for HTTP worker threads to clean up."""

    protocol_version = 'HTTP/1.1'
    """The version string to write in the Status-Line of all HTTP responses,
    for example, "HTTP/1.1" (the default). Depending on the HTTP server used,
    this should also limit the supported features used in the response."""

    thread_pool = 10
    """The number of worker threads to start up in the pool."""

    thread_pool_max = -1
    """The maximum size of the worker-thread pool. Use -1 to indicate no limit.
    """

    max_request_header_size = 500 * 1024
    """The maximum number of bytes allowable in the request headers.
    If exceeded, the HTTP server should return "413 Request Entity Too Large".
    """

    max_request_body_size = 100 * 1024 * 1024
    """The maximum number of bytes allowable in the request body. If exceeded,
    the HTTP server should return "413 Request Entity Too Large"."""

    instance = None
    """If not None, this should be an HTTP server instance (such as
    cheroot.wsgi.Server) which cherrypy.server will control.
    Use this when you need
    more control over object instantiation than is available in the various
    configuration options."""

    ssl_context = None
    """When using PyOpenSSL, an instance of SSL.Context."""

    ssl_certificate = None
    """The filename of the SSL certificate to use."""

    ssl_certificate_chain = None
    """When using PyOpenSSL, the certificate chain to pass to
    Context.load_verify_locations."""

    ssl_private_key = None
    """The filename of the private key to use with SSL."""

    ssl_ciphers = None
    """The ciphers list of SSL."""

    ssl_module = 'builtin'
    """The name of a registered SSL adaptation module to use with
    the builtin WSGI server. Builtin options are: 'builtin' (to
    use the SSL library built into recent versions of Python).
    You may also register your own classes in the
    cheroot.server.ssl_adapters dict."""

    statistics = False
    """Turns statistics-gathering on or off for aware HTTP servers."""

    nodelay = True
    """If True (the default since 3.1), sets the TCP_NODELAY socket option."""

    wsgi_version = (1, 0)
    """The WSGI version tuple to use with the builtin WSGI server.
    The provided options are (1, 0) [which includes support for PEP 3333,
    which declares it covers WSGI version 1.0.1 but still mandates the
    wsgi.version (1, 0)] and ('u', 0), an experimental unicode version.
    You may create and register your own experimental versions of the WSGI
    protocol by adding custom classes to the cheroot.server.wsgi_gateways dict.
    """

    peercreds = False
    """If True, peer cred lookup for UNIX domain socket will put to WSGI env.

    This information will then be available through WSGI env vars:
    * X_REMOTE_PID
    * X_REMOTE_UID
    * X_REMOTE_GID
    """

    peercreds_resolve = False
    """If True, username/group will be looked up in the OS from peercreds.

    This information will then be available through WSGI env vars:
    * REMOTE_USER
    * X_REMOTE_USER
    * X_REMOTE_GROUP
    """

    def __init__(self):
        """Initialize Server instance."""
        self.bus = cherrypy.engine
        self.httpserver = None
        self.interrupt = None
        self.running = False

    def httpserver_from_self(self, httpserver=None):
        """Return a (httpserver, bind_addr) pair based on self attributes."""
        if httpserver is None:
            httpserver = self.instance
        if httpserver is None:
            from cherrypy import _cpwsgi_server
            httpserver = _cpwsgi_server.CPWSGIServer(self)
        if isinstance(httpserver, text_or_bytes):
            # Is anyone using this? Can I add an arg?
            httpserver = attributes(httpserver)(self)
        return httpserver, self.bind_addr

    def start(self):
        """Start the HTTP server."""
        if not self.httpserver:
            self.httpserver, self.bind_addr = self.httpserver_from_self()
        super(Server, self).start()
    start.priority = 75

    @property
    def bind_addr(self):
        """Return bind address.

        A (host, port) tuple for TCP sockets or a str for Unix domain sockts.
        """
        if self.socket_file:
            return self.socket_file
        if self.socket_host is None and self.socket_port is None:
            return None
        return (self.socket_host, self.socket_port)

    @bind_addr.setter
    def bind_addr(self, value):
        if value is None:
            self.socket_file = None
            self.socket_host = None
            self.socket_port = None
        elif isinstance(value, text_or_bytes):
            self.socket_file = value
            self.socket_host = None
            self.socket_port = None
        else:
            try:
                self.socket_host, self.socket_port = value
                self.socket_file = None
            except ValueError:
                raise ValueError('bind_addr must be a (host, port) tuple '
                                 '(for TCP sockets) or a string (for Unix '
                                 'domain sockets), not %r' % value)

    def base(self):
        """Return the base for this server.

        e.i. scheme://host[:port] or sock file
        """
        if self.socket_file:
            return self.socket_file

        host = self.socket_host
        if host in ('0.0.0.0', '::'):
            # 0.0.0.0 is INADDR_ANY and :: is IN6ADDR_ANY.
            # Look up the host name, which should be the
            # safest thing to spit out in a URL.
            import socket
            host = socket.gethostname()

        port = self.socket_port

        if self.ssl_certificate:
            scheme = 'https'
            if port != 443:
                host += ':%s' % port
        else:
            scheme = 'http'
            if port != 80:
                host += ':%s' % port

        return '%s://%s' % (scheme, host)