A high-speed, production ready, thread pooled, generic HTTP server.
Simplest example on how to use this module directly (without using CherryPy’s application machinery):
from cherrypy import wsgiserver
def my_crazy_app(environ, start_response):
status = '200 OK'
response_headers = [('Content-type','text/plain')]
start_response(status, response_headers)
return ['Hello world!']
server = wsgiserver.CherryPyWSGIServer(
('0.0.0.0', 8070), my_crazy_app,
server_name='www.cherrypy.example')
server.start()
The CherryPy WSGI server can serve as many WSGI applications as you want in one instance by using a WSGIPathInfoDispatcher:
d = WSGIPathInfoDispatcher({'/': my_crazy_app, '/blog': my_blog_app})
server = wsgiserver.CherryPyWSGIServer(('0.0.0.0', 80), d)
Want SSL support? Just set server.ssl_adapter to an SSLAdapter instance.
This won’t call the CherryPy engine (application side) at all, only the HTTP server, which is independent from the rest of CherryPy. Don’t let the name “CherryPyWSGIServer” throw you; the name merely reflects its origin, not its coupling.
For those of you wanting to understand internals of this module, here’s the basic call flow. The server’s listening thread runs a very tight loop, sticking incoming connections onto a Queue:
server = CherryPyWSGIServer(...)
server.start()
while True:
tick()
# This blocks until a request comes in:
child = socket.accept()
conn = HTTPConnection(child, ...)
server.requests.put(conn)
Worker threads are kept in a pool and poll the Queue, popping off and then handling each connection in turn. Each connection can consist of an arbitrary number of requests and their responses, so we run a nested loop:
while True:
conn = server.requests.get()
conn.communicate()
-> while True:
req = HTTPRequest(...)
req.parse_request()
-> # Read the Request-Line, e.g. "GET /page HTTP/1.1"
req.rfile.readline()
read_headers(req.rfile, req.inheaders)
req.respond()
-> response = app(...)
try:
for chunk in response:
if chunk:
req.write(chunk)
finally:
if hasattr(response, "close"):
response.close()
if req.close_connection:
return
An HTTP Request (and response).
A single HTTP connection may consist of multiple request/response pairs.
If True, output will be encoded with the “chunked” transfer-coding.
This value is set automatically inside send_headers.
Parse a Request-URI into (scheme, authority, path).
Note that Request-URI’s must be one of:
Request-URI = "*" | absoluteURI | abs_path | authority
Therefore, a Request-URI which starts with a double forward-slash cannot be a “net_path”:
net_path = "//" authority [ abs_path ]
Instead, it must be interpreted as an “abs_path” with an empty first path segment:
abs_path = "/" path_segments
path_segments = segment *( "/" segment )
segment = *pchar *( ";" param )
param = *pchar
Assert, process, and send the HTTP response message-headers.
You must set self.status, and self.outheaders before calling this.
An HTTP connection (active socket).
server: the Server object which received this connection. socket: the raw socket object (usually TCP) for this connection. makefile: a fileobject class for reading from the socket.
An HTTP server.
The interface on which to listen for connections.
For TCP sockets, a (host, port) tuple. 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.
For UNIX sockets, supply the filename as a string.
The version string to write in the Status-Line of all HTTP responses.
For example, “HTTP/1.1” is the default. This also limits the supported features used in the response.
The value to set for the SERVER_SOFTWARE entry in the WSGI environ.
If None, this defaults to '%s Server' % self.version.
An instance of SSLAdapter (or a subclass).
You must have the corresponding SSL driver library installed.
Wraps a file-like object, returning an empty string when exhausted.
This class is intended to provide a conforming wsgi.input value for request entities that have been encoded with the ‘chunked’ transfer encoding.
Thread which continuously polls a Queue for Connection objects.
Due to the timing issues of polling a Queue, a WorkerThread does not check its own ‘ready’ flag after it has started. To stop the thread, it is necessary to stick a _SHUTDOWNREQUEST object onto the Queue (one for each running WorkerThread).
A Request Queue for the CherryPyWSGIServer which pools threads.
ThreadPool objects must provide min, get(), put(obj), start() and stop(timeout) attributes.
Base class for SSL driver library adapters.
Required methods:
- wrap(sock) -> (wrapped socket, ssl environ dict)
- makefile(sock, mode='r', bufsize=DEFAULT_BUFFER_SIZE) -> socket file object
WSGI callable to write unbuffered data to the client.
This method is also used internally by start_response (to write data from the iterable returned by the WSGI application).
A WSGI dispatcher for dispatch based on the PATH_INFO.
apps: a dict or list of (path_prefix, app) pairs.