Plug our Flask app into Nailgun's web.py

tuning_box/nailgun.py

@@ -12,11 +12,66 @@
 
 from __future__ import absolute_import
 
+import itertools
 import os
+import threading
 
+from nailgun import db as nailgun_db
 from nailgun import extensions
+import web
 
 import tuning_box
+from tuning_box import app as tb_app
+from tuning_box import db as tb_db
+
+
+class App2WebPy(web.application):
+    def __init__(self):
+        web.application.__init__(self)
+        self.__name__ = self
+        self.app = None
+        self.lock = threading.Lock()
+
+    def create_app(self):
+        raise NotImplementedError
+
+    def get_app(self):
+        with self.lock:
+            if not self.app:
+                self.app = self.create_app()
+            return self.app
+
+    def handle(self):
+        written_data = []
+
+        def write(data):
+            assert start_response.called
+            written_data.append(data)
+
+        def start_response(status, headers, exc_info=None):
+            assert not start_response.called
+            assert not exc_info
+            start_response.called = True
+            web.ctx.status = status
+            web.ctx.headers.extend(headers)
+            return write
+
+        start_response.called = False
+
+        app = self.get_app()
+        environ = dict(web.ctx.environ)
+        environ["PATH_INFO"] = environ["REQUEST_URI"] = web.ctx.path
+        result = app(environ, start_response)
+        return itertools.chain(written_data, result)
+
+
+class TB2WebPy(App2WebPy):
+    def create_app(self):
+        app = tb_app.build_app()
+        tb_db.prefix_tables(Extension.table_prefix())
+        tb_db.db.session = nailgun_db.db
+        app.config["PROPAGATE_EXCEPTIONS"] = True
+        return app
 
 
 class Extension(extensions.BaseExtension):
@@ -24,6 +79,8 @@ class Extension(extensions.BaseExtension):
     version = tuning_box.__version__
     description = 'Plug tuning_box endpoints into Nailgun itself'
 
+    urls = [{'uri': '/config', 'handler': TB2WebPy()}]
+
     @classmethod
     def alembic_migrations_path(cls):
         return os.path.join(os.path.dirname(__file__), 'migrations')