Added mod_wsgi handler

This is an alternative Python handler for the XML-RPC server, making
use of the WSGI platform instead.

If the rteval_xmlrpc.wsgi script is started manually, using python
it will act as a standalone server, listening to localhost:65432
as default.

This script can also be loaded by, f.ex., the mod_wsgi module to
Apache.  A template for Apache config is also added.

Signed-off-by: David Sommerseth <davids@redhat.com>

2 files changed, 154 insertions, 0 deletions

diff --git a/server/apache-rteval-wsgi.conf.tpl b/server/apache-rteval-wsgi.conf.tpl
new file mode 100644
index 0000000..9bf5fea
--- /dev/null
+++ b/server/apache-rteval-wsgi.conf.tpl
@@ -0,0 +1,41 @@
+# File: apache-rteval.conf
+#
+# Apache config entry to enable the rteval XML-RPC server
+#
+#   Copyright 2011      David Sommerseth <davids@redhat.com>
+#
+#   This program is free software; you can redistribute it and/or modify
+#   it under the terms of the GNU General Public License as published by
+#   the Free Software Foundation; either version 2 of the License, or
+#   (at your option) any later version.
+#
+#   This program is distributed in the hope that it will be useful,
+#   but WITHOUT ANY WARRANTY; without even the implied warranty of
+#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#   GNU General Public License for more details.
+#
+#   You should have received a copy of the GNU General Public License
+#   along with this program; if not, write to the Free Software
+#   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+#
+#   For the avoidance of doubt the "preferred form" of this code is one which
+#   is in an open unpatent encumbered format. Where cryptographic key signing
+#   forms part of the process of creating an executable the information
+#   including keys needed to generate an equivalently functional executable
+#   are deemed to be part of the source code.
+#
+
+WSGISocketPrefix /var/run/wsgi
+WSGIDaemonProcess rtevalxmlrpc processes=3 threads=15 python-path={_INSTALLDIR_}
+WSGIScriptAlias /rteval/API1 {_INSTALLDIR_}/rteval_xmlrpc.wsgi
+
+<Directory "{_INSTALLDIR_}">
+    Options Indexes FollowSymLinks
+    AllowOverride None
+    Order allow,deny
+    Allow from all
+
+    WSGIProcessGroup rtevalxmlrpc
+    WSGICallableObject rtevalXMLRPC_handler
+</Directory>
+
diff --git a/server/rteval_xmlrpc.wsgi b/server/rteval_xmlrpc.wsgi
new file mode 100644
index 0000000..f782657
--- /dev/null
+++ b/server/rteval_xmlrpc.wsgi
@@ -0,0 +1,113 @@
+#
+#   rteval_xmlrpc.wsgi
+#   XML-RPC handler for the rteval server, using mod_wsgi
+#
+#   Copyright 2011      David Sommerseth <davids@redhat.com>
+#
+#   This program is free software; you can redistribute it and/or modify
+#   it under the terms of the GNU General Public License as published by
+#   the Free Software Foundation; either version 2 of the License, or
+#   (at your option) any later version.
+#
+#   This program is distributed in the hope that it will be useful,
+#   but WITHOUT ANY WARRANTY; without even the implied warranty of
+#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#   GNU General Public License for more details.
+#
+#   You should have received a copy of the GNU General Public License
+#   along with this program; if not, write to the Free Software
+#   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+#
+#   For the avoidance of doubt the "preferred form" of this code is one which
+#   is in an open unpatent encumbered format. Where cryptographic key signing
+#   forms part of the process of creating an executable the information
+#   including keys needed to generate an equivalently functional executable
+#   are deemed to be part of the source code.
+#
+
+from wsgiref.simple_server import make_server
+import types
+from xmlrpclib import dumps, loads, Fault
+from xmlrpc_API1 import XMLRPC_API1
+from rteval.rtevalConfig import rtevalConfig
+
+def rtevalXMLRPC_Dispatch(method, args):
+    # Default configuration
+    defcfg = {'xmlrpc_server': { 'datadir':     './var/lib/rteval',
+                                 'db_server':   'localhost',
+                                 'db_port':     5432,
+                                 'database':    'rteval',
+                                 'db_username': 'rtevxmlrpc',
+                                 'db_password': 'rtevaldb'
+                                 }
+              }
+
+    # Fetch configuration
+    cfg = rtevalConfig(defcfg)
+    cfg.Load(append=True)
+
+    # Prepare an object for executing the query
+    xmlrpc = XMLRPC_API1(config=cfg.GetSection('xmlrpc_server'))
+
+    # Exectute it
+    result = xmlrpc.Dispatch(method, args)
+
+    # Send the result
+    if type(result) == types.TupleType:
+        return dumps(result, None, methodresponse=1)
+    else:
+        return dumps((result,), None, methodresponse=1)
+
+
+def rtevalXMLRPC_handler(environ, start_response):
+
+   # the environment variable CONTENT_LENGTH may be empty or missing
+   try:
+      request_body_size = int(environ.get('CONTENT_LENGTH', 0))
+   except (ValueError):
+      request_body_size = 0
+
+   # When the method is POST the query string will be sent
+   # in the HTTP request body which is passed by the WSGI server
+   # in the file like wsgi.input environment variable.
+   try:
+       if (environ['REQUEST_METHOD'] != 'POST') or (request_body_size < 1):
+           raise Exception('Error in request')
+
+       request_body = environ['wsgi.input'].read(request_body_size)
+       try:
+           args, method = loads(request_body)
+       except:
+           raise Exception('Invalid XML-RPC request')
+
+       # Execute the XML-RPC call
+       status = '200 OK'
+       cont_type = 'text/xml'
+       response = [rtevalXMLRPC_Dispatch(method, args)]
+   except Exception, ex:
+       status = '500 Internal server error: %s' % str(ex)
+       cont_type = 'text/plain'
+       response = [
+           '500 Internal server error\n',
+           'ERROR: %s' % str(ex)
+           ]
+       import traceback, sys
+       traceback.print_exc(file=sys.stderr)
+
+   response_headers = [('Content-Type', cont_type),
+                       ('Content-Length', str(len("".join(response))))]
+   start_response(status, response_headers)
+   return response
+
+
+if __name__ == '__main__':
+    #
+    # Simple stand-alone XML-RPC server, if started manually
+    # Not suitable for production environments, but for testing
+    #
+    httpd = make_server('localhost', 65432, rtevalXMLRPC_handler)
+    try:
+        httpd.serve_forever()
+    except KeyboardInterrupt:
+        print "\nShutting down"
+