Add WSGI application support and documentation

README.txt

@@ -24,3 +24,5 @@ Usage:
 
   nilmdb-server --help
   nilmtool --help
+
+See docs/wsgi.md for info on setting up a WSGI application in Apache.

docs/wsgi.md

@@ -0,0 +1,18 @@
+WSGI Application in Apache
+--------------------------
+
+Apache configuration should look something like:
+
+    <VirtualHost>
+        WSGIScriptAlias /nilmdb /home/nilmdb/nilmdb.wsgi
+        WSGIApplicationGroup nilmdb
+        WSGIProcessGroup nilmdb
+        WSGIDaemonProcess nilmdb threads=32
+    </VirtualHost>
+	
+where `/home/nilmdb/nilmdb.wsgi` is a file containing:
+
+    import nilmdb.server
+	application = nilmdb.server.wsgi_application("/home/nilmdb/db")
+	
+where `/home/nilmdb/db` is the path to the database.

nilmdb/server/__init__.py

@@ -17,5 +17,5 @@ except (ImportError, TypeError): # pragma: no cover
     pass
 
 from nilmdb.server.nilmdb import NilmDB
-from nilmdb.server.server import Server
+from nilmdb.server.server import Server, wsgi_application
 from nilmdb.server.errors import NilmDBError, StreamError, OverlapError

nilmdb/server/server.py

@@ -536,6 +536,14 @@ class Server(object):
         else:
             cherrypy.server.shutdown_timeout = 5
 
+    def get_application(self):
+        """Return a WSGI application object"""
+        def app(environ, start_response):
+            if environ['wsgi.multiprocess']:
+                raise Exception("can't function in a multi-process environment")
+            return cherrypy.tree(environ, start_response)
+        return app
+
     def json_error_page(self, status, message, traceback, version):
         """Return a custom error page in JSON so the client can parse it"""
         errordata = { "status" : status,
@@ -602,3 +610,10 @@ class Server(object):
 
     def stop(self):
         cherrypy.engine.exit()
+
+def wsgi_application(dbpath):
+    """Return a WSGI application object with a database at the
+    specified path."""
+    db = nilmdb.utils.serializer_proxy(nilmdb.server.NilmDB)(dbpath)
+    server = nilmdb.server.Server(db, embedded = True)
+    return server.get_application()