/usr/share/pyshared/paste/util/scgiserver.py is in python-paste 1.7.5.1-4ubuntu2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 | """
SCGI-->WSGI application proxy, "SWAP".
(Originally written by Titus Brown.)
This lets an SCGI front-end like mod_scgi be used to execute WSGI
application objects. To use it, subclass the SWAP class like so::
class TestAppHandler(swap.SWAP):
def __init__(self, *args, **kwargs):
self.prefix = '/canal'
self.app_obj = TestAppClass
swap.SWAP.__init__(self, *args, **kwargs)
where 'TestAppClass' is the application object from WSGI and '/canal'
is the prefix for what is served by the SCGI Web-server-side process.
Then execute the SCGI handler "as usual" by doing something like this::
scgi_server.SCGIServer(TestAppHandler, port=4000).serve()
and point mod_scgi (or whatever your SCGI front end is) at port 4000.
Kudos to the WSGI folk for writing a nice PEP & the Quixote folk for
writing a nice extensible SCGI server for Python!
"""
import sys
import time
from scgi import scgi_server
def debug(msg):
timestamp = time.strftime("%Y-%m-%d %H:%M:%S",
time.localtime(time.time()))
sys.stderr.write("[%s] %s\n" % (timestamp, msg))
class SWAP(scgi_server.SCGIHandler):
"""
SCGI->WSGI application proxy: let an SCGI server execute WSGI
application objects.
"""
app_obj = None
prefix = None
def __init__(self, *args, **kwargs):
assert self.app_obj, "must set app_obj"
assert self.prefix is not None, "must set prefix"
args = (self,) + args
scgi_server.SCGIHandler.__init__(*args, **kwargs)
def handle_connection(self, conn):
"""
Handle an individual connection.
"""
input = conn.makefile("r")
output = conn.makefile("w")
environ = self.read_env(input)
environ['wsgi.input'] = input
environ['wsgi.errors'] = sys.stderr
environ['wsgi.version'] = (1, 0)
environ['wsgi.multithread'] = False
environ['wsgi.multiprocess'] = True
environ['wsgi.run_once'] = False
# dunno how SCGI does HTTPS signalling; can't test it myself... @CTB
if environ.get('HTTPS','off') in ('on','1'):
environ['wsgi.url_scheme'] = 'https'
else:
environ['wsgi.url_scheme'] = 'http'
## SCGI does some weird environ manglement. We need to set
## SCRIPT_NAME from 'prefix' and then set PATH_INFO from
## REQUEST_URI.
prefix = self.prefix
path = environ['REQUEST_URI'][len(prefix):].split('?', 1)[0]
environ['SCRIPT_NAME'] = prefix
environ['PATH_INFO'] = path
headers_set = []
headers_sent = []
chunks = []
def write(data):
chunks.append(data)
def start_response(status, response_headers, exc_info=None):
if exc_info:
try:
if headers_sent:
# Re-raise original exception if headers sent
raise exc_info[0], exc_info[1], exc_info[2]
finally:
exc_info = None # avoid dangling circular ref
elif headers_set:
raise AssertionError("Headers already set!")
headers_set[:] = [status, response_headers]
return write
###
result = self.app_obj(environ, start_response)
try:
for data in result:
chunks.append(data)
# Before the first output, send the stored headers
if not headers_set:
# Error -- the app never called start_response
status = '500 Server Error'
response_headers = [('Content-type', 'text/html')]
chunks = ["XXX start_response never called"]
else:
status, response_headers = headers_sent[:] = headers_set
output.write('Status: %s\r\n' % status)
for header in response_headers:
output.write('%s: %s\r\n' % header)
output.write('\r\n')
for data in chunks:
output.write(data)
finally:
if hasattr(result,'close'):
result.close()
# SCGI backends use connection closing to signal 'fini'.
try:
input.close()
output.close()
conn.close()
except IOError, err:
debug("IOError while closing connection ignored: %s" % err)
def serve_application(application, prefix, port=None, host=None, max_children=None):
"""
Serve the specified WSGI application via SCGI proxy.
``application``
The WSGI application to serve.
``prefix``
The prefix for what is served by the SCGI Web-server-side process.
``port``
Optional port to bind the SCGI proxy to. Defaults to SCGIServer's
default port value.
``host``
Optional host to bind the SCGI proxy to. Defaults to SCGIServer's
default host value.
``host``
Optional maximum number of child processes the SCGIServer will
spawn. Defaults to SCGIServer's default max_children value.
"""
class SCGIAppHandler(SWAP):
def __init__ (self, *args, **kwargs):
self.prefix = prefix
self.app_obj = application
SWAP.__init__(self, *args, **kwargs)
kwargs = dict(handler_class=SCGIAppHandler)
for kwarg in ('host', 'port', 'max_children'):
if locals()[kwarg] is not None:
kwargs[kwarg] = locals()[kwarg]
scgi_server.SCGIServer(**kwargs).serve()
|