| author |
Steve Losh <steve@stevelosh.com> |
| date |
Tue, 02 Mar 2010 19:45:54 -0500 |
| parents |
(none) |
| children |
(none) |
"""Native adapter for serving CherryPy via mod_python
Basic usage:
##########################################
# Application in a module called myapp.py
##########################################
import cherrypy
class Root:
@cherrypy.expose
def index(self):
return 'Hi there, Ho there, Hey there'
# We will use this method from the mod_python configuration
# as the entry point to our application
def setup_server():
cherrypy.tree.mount(Root())
cherrypy.config.update({'environment': 'production',
'log.screen': False,
'show_tracebacks': False})
##########################################
# mod_python settings for apache2
# This should reside in your httpd.conf
# or a file that will be loaded at
# apache startup
##########################################
# Start
DocumentRoot "/"
Listen 8080
LoadModule python_module /usr/lib/apache2/modules/mod_python.so
<Location "/">
PythonPath "sys.path+['/path/to/my/application']"
SetHandler python-program
PythonHandler cherrypy._cpmodpy::handler
PythonOption cherrypy.setup myapp::setup_server
PythonDebug On
</Location>
# End
The actual path to your mod_python.so is dependent on your
environment. In this case we suppose a global mod_python
installation on a Linux distribution such as Ubuntu.
We do set the PythonPath configuration setting so that
your application can be found by from the user running
the apache2 instance. Of course if your application
resides in the global site-package this won't be needed.
Then restart apache2 and access http://127.0.0.1:8080
"""
import logging
try:
from cStringIO import StringIO
except ImportError:
from StringIO import StringIO
import cherrypy
from cherrypy._cperror import format_exc, bare_error
from cherrypy.lib import httputil
# ------------------------------ Request-handling
def setup(req):
from mod_python import apache
# Run any setup functions defined by a "PythonOption cherrypy.setup" directive.
options = req.get_options()
if 'cherrypy.setup' in options:
for function in options['cherrypy.setup'].split():
atoms = function.split('::', 1)
if len(atoms) == 1:
mod = __import__(atoms[0], globals(), locals())
else:
modname, fname = atoms
mod = __import__(modname, globals(), locals(), [fname])
func = getattr(mod, fname)
func()
cherrypy.config.update({'log.screen': False,
"tools.ignore_headers.on": True,
"tools.ignore_headers.headers": ['Range'],
})
engine = cherrypy.engine
if hasattr(engine, "signal_handler"):
engine.signal_handler.unsubscribe()
if hasattr(engine, "console_control_handler"):
engine.console_control_handler.unsubscribe()
engine.autoreload.unsubscribe()
cherrypy.server.unsubscribe()
def _log(msg, level):
newlevel = apache.APLOG_ERR
if logging.DEBUG >= level:
newlevel = apache.APLOG_DEBUG
elif logging.INFO >= level:
newlevel = apache.APLOG_INFO
elif logging.WARNING >= level:
newlevel = apache.APLOG_WARNING
# On Windows, req.server is required or the msg will vanish. See
# http://www.modpython.org/pipermail/mod_python/2003-October/014291.html.
# Also, "When server is not specified...LogLevel does not apply..."
apache.log_error(msg, newlevel, req.server)
engine.subscribe('log', _log)
engine.start()
def cherrypy_cleanup(data):
engine.exit()
try:
# apache.register_cleanup wasn't available until 3.1.4.
apache.register_cleanup(cherrypy_cleanup)
except AttributeError:
req.server.register_cleanup(req, cherrypy_cleanup)
class _ReadOnlyRequest:
expose = ('read', 'readline', 'readlines')
def __init__(self, req):
for method in self.expose:
self.__dict__[method] = getattr(req, method)
recursive = False
_isSetUp = False
def handler(req):
from mod_python import apache
try:
global _isSetUp
if not _isSetUp:
setup(req)
_isSetUp = True
# Obtain a Request object from CherryPy
local = req.connection.local_addr
local = httputil.Host(local[0], local[1], req.connection.local_host or "")
remote = req.connection.remote_addr
remote = httputil.Host(remote[0], remote[1], req.connection.remote_host or "")
scheme = req.parsed_uri[0] or 'http'
req.get_basic_auth_pw()
try:
# apache.mpm_query only became available in mod_python 3.1
q = apache.mpm_query
threaded = q(apache.AP_MPMQ_IS_THREADED)
forked = q(apache.AP_MPMQ_IS_FORKED)
except AttributeError:
bad_value = ("You must provide a PythonOption '%s', "
"either 'on' or 'off', when running a version "
"of mod_python < 3.1")
threaded = options.get('multithread', '').lower()
if threaded == 'on':
threaded = True
elif threaded == 'off':
threaded = False
else:
raise ValueError(bad_value % "multithread")
forked = options.get('multiprocess', '').lower()
if forked == 'on':
forked = True
elif forked == 'off':
forked = False
else:
raise ValueError(bad_value % "multiprocess")
sn = cherrypy.tree.script_name(req.uri or "/")
if sn is None:
send_response(req, '404 Not Found', [], '')
else:
app = cherrypy.tree.apps[sn]
method = req.method
path = req.uri
qs = req.args or ""
reqproto = req.protocol
headers = req.headers_in.items()
rfile = _ReadOnlyRequest(req)
prev = None
try:
redirections = []
while True:
request, response = app.get_serving(local, remote, scheme,
"HTTP/1.1")
request.login = req.user
request.multithread = bool(threaded)
request.multiprocess = bool(forked)
request.app = app
request.prev = prev
# Run the CherryPy Request object and obtain the response
try:
request.run(method, path, qs, reqproto, headers, rfile)
break
except cherrypy.InternalRedirect, ir:
app.release_serving()
prev = request
if not recursive:
if ir.path in redirections:
raise RuntimeError("InternalRedirector visited the "
"same URL twice: %r" % ir.path)
else:
# Add the *previous* path_info + qs to redirections.
if qs:
qs = "?" + qs
redirections.append(sn + path + qs)
# Munge environment and try again.
method = "GET"
path = ir.path
qs = ir.query_string
rfile = StringIO()
send_response(req, response.status, response.header_list,
response.body, response.stream)
finally:
app.release_serving()
except:
tb = format_exc()
cherrypy.log(tb, 'MOD_PYTHON', severity=logging.ERROR)
s, h, b = bare_error()
send_response(req, s, h, b)
return apache.OK
def send_response(req, status, headers, body, stream=False):
# Set response status
req.status = int(status[:3])
# Set response headers
req.content_type = "text/plain"
for header, value in headers:
if header.lower() == 'content-type':
req.content_type = value
continue
req.headers_out.add(header, value)
if stream:
# Flush now so the status and headers are sent immediately.
req.flush()
# Set response body
if isinstance(body, basestring):
req.write(body)
else:
for seg in body:
req.write(seg)
# --------------- Startup tools for CherryPy + mod_python --------------- #
import os
import re
def read_process(cmd, args=""):
pipein, pipeout = os.popen4("%s %s" % (cmd, args))
try:
firstline = pipeout.readline()
if (re.search(r"(not recognized|No such file|not found)", firstline,
re.IGNORECASE)):
raise IOError('%s must be on your system path.' % cmd)
output = firstline + pipeout.read()
finally:
pipeout.close()
return output
class ModPythonServer(object):
template = """
# Apache2 server configuration file for running CherryPy with mod_python.
DocumentRoot "/"
Listen %(port)s
LoadModule python_module modules/mod_python.so
<Location %(loc)s>
SetHandler python-program
PythonHandler %(handler)s
PythonDebug On
%(opts)s
</Location>
"""
def __init__(self, loc="/", port=80, opts=None, apache_path="apache",
handler="cherrypy._cpmodpy::handler"):
self.loc = loc
self.port = port
self.opts = opts
self.apache_path = apache_path
self.handler = handler
def start(self):
opts = "".join([" PythonOption %s %s\n" % (k, v)
for k, v in self.opts])
conf_data = self.template % {"port": self.port,
"loc": self.loc,
"opts": opts,
"handler": self.handler,
}
mpconf = os.path.join(os.path.dirname(__file__), "cpmodpy.conf")
f = open(mpconf, 'wb')
try:
f.write(conf_data)
finally:
f.close()
response = read_process(self.apache_path, "-k start -f %s" % mpconf)
self.ready = True
return response
def stop(self):
os.popen("apache -k stop")
self.ready = False