add aiohttp app middleware reference

buckler_aiohttp.py

@@ -0,0 +1,61 @@
+#!/usr/bin/env python3
+"""
+Session interface middlewares to integrate the aiohttp app with Buckler.
+"""
+import json
+from datetime import datetime
+
+import aiohttp
+from aiohttp import web
+
+import config
+
+@web.middleware
+async def buckler_session(request, handler):
+	"""
+	Verifies the user with the configured Buckler app and retrieves any
+	session data they may have. Redirects them to the login page otherwise.
+	"""
+	user_id = request.cookies.get('userid')
+	user_sid = request.cookies.get('session')
+
+	url = config.buckler['url'] + '/get_session'
+	params = {
+		'app_id': config.buckler['app_id'],
+		'app_key': config.buckler['app_key'],
+		'userid': user_id,
+		'session': user_sid
+	}
+	async with aiohttp.ClientSession() as session:
+		async with session.get(url, params=params) as resp:
+			data = await resp.json()
+			if data.get('error'):
+				raise web.HTTPFound(location=config.buckler['login_url'])
+			request['session'] = data['session_data']
+			request['meta'] = data['meta']
+
+		resp = await handler(request)
+
+		if request['session'] != data['session_data']: # session data modified
+			url = config.buckler['url'] + '/set_session'
+			data = json.dumps(request['session'])
+			session.post(url, params=params, data=data) # TODO: error handle?
+
+		last_used = datetime.fromisoformat(request['meta']['last_used'])
+		now = datetime.now(last_used.tzinfo)
+		delta = now - last_used
+		if delta.seconds > 600:
+			resp.set_cookie(
+				'userid',
+				user_id,
+				max_age=30*24*60*60,
+				secure=True,
+				httponly=True)
+			resp.set_cookie(
+				'session',
+				user_sid,
+				max_age=30*24*60*60,
+				secure=True,
+				httponly=True)
+
+	return resp