"""Manage an HTTP server with CherryPy.""" import socket import threading import time import cherrypy from cherrypy.lib import attributes class Server(object): """Manager for a set of HTTP servers. This is both a container and controller for "HTTP server" objects, which are kept in Server.httpservers, a dictionary of the form: {httpserver: bind_addr} where 'bind_addr' is usually a (host, port) tuple. Most often, you will only be starting a single HTTP server. In this common case, 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.server.quickstart() But if you need to start more than one HTTP server (to serve on multiple ports, or protocols, etc.), you can manually register each one and then control them all through this object: s1 = MyWSGIServer(host='', port=80) s2 = another.HTTPServer(host='localhost', SSL=True) cherrypy.server.httpservers = {s1: ('', 80), s2: ('localhost', 443)} # Note we do not use quickstart when we define our own httpservers cherrypy.server.start() Whether you use quickstart(), or define your own httpserver entries and use start(), you'll find that the start, wait, restart, and stop methods work the same way, controlling all registered httpserver objects at once. """ socket_port = 8080 socket_host = '' socket_file = '' socket_queue_size = 5 socket_timeout = 10 protocol_version = 'HTTP/1.1' reverse_dns = False thread_pool = 10 max_request_header_size = 500 * 1024 max_request_body_size = 100 * 1024 * 1024 instance = None ssl_certificate = None ssl_private_key = None def __init__(self): self.httpservers = {} self.interrupt = None def quickstart(self, server=None): """Start from defaults. MUST be called from the main thread. This function works like CherryPy 2's server.start(). It loads and starts an httpserver based on the given server object (if provided) and attributes of self. """ httpserver, bind_addr = self.httpserver_from_self(server) self.httpservers[httpserver] = bind_addr self.start() 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 httpserver = _cpwsgi.CPWSGIServer() if isinstance(httpserver, basestring): httpserver = attributes(httpserver)() if self.socket_file: return httpserver, self.socket_file host = self.socket_host port = self.socket_port return httpserver, (host, port) def start(self): """Start all registered HTTP servers.""" self.interrupt = None if not self.httpservers: raise ValueError("No HTTP servers have been created. " "Try server.quickstart instead.") for httpserver in self.httpservers: self._start_http(httpserver) def _start_http(self, httpserver): """Start the given httpserver in a new thread.""" scheme = "http" if getattr(httpserver, "ssl_certificate", None): scheme = "https" bind_addr = self.httpservers[httpserver] if isinstance(bind_addr, tuple): wait_for_free_port(*bind_addr) host, port = bind_addr if not host: host = '0.0.0.0' on_what = "%s://%s:%s/" % (scheme, host, port) else: on_what = "socket file: %s" % bind_addr t = threading.Thread(target=self._start_http_thread, args=(httpserver,)) t.setName("CPHTTPServer " + t.getName()) t.start() self.wait(httpserver) cherrypy.log("Serving %s on %s" % (scheme.upper(), on_what), 'HTTP') def _start_http_thread(self, httpserver): """HTTP servers MUST be started in new threads, so that the main thread persists to receive KeyboardInterrupt's. If an exception is raised in the httpserver's thread then it's trapped here, and the httpserver(s) and engine are shut down. """ try: httpserver.start() except KeyboardInterrupt, exc: cherrypy.log(" hit: shutting down HTTP servers", "SERVER") self.interrupt = exc self.stop() cherrypy.engine.stop() except SystemExit, exc: cherrypy.log("SystemExit raised: shutting down HTTP servers", "SERVER") self.interrupt = exc self.stop() cherrypy.engine.stop() raise def wait(self, httpserver=None): """Wait until the HTTP server is ready to receive requests. If no httpserver is specified, wait for all registered httpservers. """ if httpserver is None: httpservers = self.httpservers.items() else: httpservers = [(httpserver, self.httpservers[httpserver])] for httpserver, bind_addr in httpservers: while not (getattr(httpserver, "ready", False) or self.interrupt): time.sleep(.1) if self.interrupt: raise self.interrupt # Wait for port to be occupied if isinstance(bind_addr, tuple): wait_for_occupied_port(*bind_addr) def stop(self): """Stop all HTTP servers.""" for httpserver, bind_addr in self.httpservers.items(): try: httpstop = httpserver.stop except AttributeError: pass else: # httpstop() MUST block until the server is *truly* stopped. httpstop() if isinstance(bind_addr, tuple): wait_for_free_port(*bind_addr) cherrypy.log("HTTP Server shut down", "HTTP") def restart(self): """Restart all HTTP servers.""" self.stop() self.start() def check_port(host, port): """Raise an error if the given port is not free on the given host.""" if not host: # The empty string signifies INADDR_ANY, # which should respond on localhost. host = 'localhost' port = int(port) # AF_INET or AF_INET6 socket # Get the correct address family for our host (allows IPv6 addresses) for res in socket.getaddrinfo(host, port, socket.AF_UNSPEC, socket.SOCK_STREAM): af, socktype, proto, canonname, sa = res s = None try: s = socket.socket(af, socktype, proto) # See http://groups.google.com/group/cherrypy-users/ # browse_frm/thread/bbfe5eb39c904fe0 s.settimeout(1.0) s.connect((host, port)) s.close() raise IOError("Port %s is in use on %s; perhaps the previous " "httpserver did not shut down properly." % (repr(port), repr(host))) except socket.error: if s: s.close() def wait_for_free_port(host, port): """Wait for the specified port to become free (drop requests).""" if not host: # The empty string signifies INADDR_ANY, # which should respond on localhost. host = 'localhost' for trial in xrange(50): try: check_port(host, port) except IOError: # Give the old server thread time to free the port. time.sleep(.1) else: return msg = "Port %s not free on %s" % (repr(port), repr(host)) cherrypy.log(msg, 'HTTP') raise IOError(msg) def wait_for_occupied_port(host, port): """Wait for the specified port to become active (receive requests).""" if not host: # The empty string signifies INADDR_ANY, # which should respond on localhost. host = 'localhost' for trial in xrange(50): try: check_port(host, port) except IOError: return else: time.sleep(.1) msg = "Port %s not bound on %s" % (repr(port), repr(host)) cherrypy.log(msg, 'HTTP') raise IOError(msg)