Dockerfile

@@ -1,7 +1,9 @@
 FROM alpine:latest
 
 RUN apk add --update --no-cache \
-	bash python3 py3-pip nginx uwsgi uwsgi-python3 certbot certbot-nginx
+	bash python3 py3-pip nginx uwsgi uwsgi-python3 certbot certbot-nginx npm jq
+
+RUN npm install -g web-push
 
 
 

INSTALL.md

@@ -161,3 +161,40 @@ jänE   doé
 ```
 
 would still work, but `Jane D` wouldn't).
+
+### Automatic data deletion (GDPR compliance)
+
+The `delete_after_days` configuration option can be set to a number of days
+after which attendance records are purged from the database. If it is not set
+(or empty) automatic deletion is deactivated. Automatic deletion is final and
+non-recoverable. This option is intended to help make the system fully GDPR
+compliant by guaranteeing deletion after a certain period. Keep in mind that a
+legally binding data protection guideline and user consent are still required.
+
+### User notification on forgotten sign-out
+
+`ftracker` is capable of notifying users if they forgot to sign-out at the end
+of a day using modern web push notifications using the VAPID system. To make
+this work, a few things are needed:
+
+Firstly, you need an EC-Prime256v1 keypair in base64url encoding. If you're
+using the Docker container, this is automatically generated for you. If not,
+the easiest way to create one is to install the `web-push` `npm` package and
+run it:
+
+```bash
+sudo npm install -g web-push
+web-push generate-vapid-keys
+```
+
+The keys then need to be copied into the config options `push_public_key` and
+`push_private_key` respectively so the backend can handle the rest.
+
+Next, to be VAPID compliant you have to announce an contact address claim to
+the push services so they can contact you if anything is going wrong with your
+notifications. Do this by entering your email address as a `mailto:` link in
+the `push_sender_info` option, like `mailto:it@fasttube.de`.
+
+Finally, you can use the `notify_after_hrs` option to specify how long the
+system should wait after a user's arrival to notify them of their missing
+departure.

config.ini

@@ -24,3 +24,13 @@ guideline_url = https://fasttube.de/wp-content/uploads/2020/12/Cororna-Regeln-St
 
 # JSON indentation for debugging
 json_indent = 4
+
+# VAPID credentials for push notifications
+# private key: base64url encoded public part of an EC-Prime256v1 keypair. See INSTALL.md
+# private key: base64url encoded private part of an EC-Prime256v1 keypair. See INSTALL.md
+# sender info: usually mailto link to responsible party to contact about issues
+push_public_key = BBwBPYxhogHLU3B1FpxfQNzO3q7qZpmD1n1KaaL8WJbcVmJSHhi1uB-VmvsVjjUHWYCeqKyLT7w-1LBfpIcbbcg
+push_private_key = abcdefghijklm_NOPQRSTUVWXYZ-0123456789
+push_sender_info = mailto:it@fasttube.de
+# when to notify users, in hours after arrival
+notify_after_hrs = 10

ftracker/config.py

@@ -9,17 +9,17 @@ class Config:
 		def findConfigFile():
 			if len(sys.argv) > 1:
 				return sys.argv[1]
-			elif Path('config.ini').is_file():
-				return 'config.ini'
 			elif Path('/etc/ftracker/config.ini').is_file():
 				return '/etc/ftracker/config.ini'
+			elif Path('config.ini').is_file():
+				return 'config.ini'
 			else:
 				return None
 
 		configfile = findConfigFile()
 
 		if configfile:
-			self.config = ConfigParser()
+			self.config = ConfigParser(strict=False)
 			self.config.read(configfile)
 		else:
 			raise Exception("No config file found")
@@ -30,3 +30,6 @@ class Config:
 
 	def __getitem__(self, key):
 		return self.config['global'].get(key)
+
+	def __repr__(self):
+		return repr(self.config.items('global'))

ftracker/core.py

@@ -26,6 +26,15 @@ if config['delete_after_days']:
 	from .deleter import Deleter
 	deleter = Deleter(db, int(config['delete_after_days']))
 
+
+if config['notify_after_hrs']:
+	from .notifier import Notifier
+	notifier = Notifier(db, int(config['notify_after_hrs']), {
+		'private_key': config['push_private_key'],
+		'claims': {'sub': config['push_sender_info']}
+	})
+
+
 def shutdown():
 	print('\rReceived stop signal, stopping threads...')
 	deleter.stop()
@@ -33,6 +42,7 @@ def shutdown():
 
 atexit.register(shutdown)
 
+
 @app.route('/guidelines')
 def get_guidelines():
 	dest = config['guideline_url'] or None
@@ -159,3 +169,62 @@ def get_data():
 	)
 
 	return json.dumps(r, indent=SPACES), 200
+
+
+@app.route('/pushinfo')
+def get_pushinfo():
+
+	if config['notify_after_hrs']:
+
+		r = {
+			'enabled': True,
+			'publickey': config['push_public_key']
+		}
+
+	else:
+
+		r = {
+			'enabled': False,
+			'publickey': None
+		}
+
+	return json.dumps(r, indent=SPACES), 200
+
+@app.route('/pushsubscribe', methods=['POST'])
+def post_pushsub():
+
+	try:
+		payload = request.data.decode('UTF-8')
+		data = json.loads(payload)
+	except ValueError as e:
+		return 'Error: JSON decode error:\n' + str(e), 400
+
+	notifier.subscribe_user(data)
+
+	return 'OK', 201
+
+@app.route('/testpush/<name>')
+def testpush(name):
+
+	if not 'Authorization' in request.headers:
+		return 'Error: No Authorization', 401, {'WWW-Authenticate': 'Basic'}
+
+	if request.authorization.username != config['admin_user']:
+		return "Wrong username", 403
+
+	if request.authorization.password != config['admin_pass']:
+		return "Wrong password", 403
+
+	Entry = Query()
+	arrivals = db.search((Entry.name == name) & (Entry.departure == None))
+
+	if len(arrivals) == 0:
+		print("User is not logged in :(")
+		return "Error: User is not logged in :(", 409
+
+	error = notifier.notify_user(arrivals[0])
+
+	if error:
+		return 'Error: ' + error, 404
+
+	return 'OK', 201

ftracker/notifier.py

@@ -0,0 +1,97 @@
+import json
+from slugify import slugify
+from threading import Thread, Event
+from datetime import datetime, timedelta
+
+from tinydb import Query
+
+from pywebpush import webpush, WebPushException
+
+ONE_HOUR_IN_S = 60 * 60
+
+class Notifier(Thread):
+
+	def subscribe_user(self, data):
+
+		pushsubs = self.db.table('pushsubs')
+
+		name = slugify(data['name'])
+		data['name'] = name
+
+		Entry = Query()
+		pushsubs.upsert(data, Entry.name == name)
+
+	def notify_user(self, arrival):
+
+		pushsubs = self.db.table('pushsubs')
+
+		Entry = Query()
+		ps = pushsubs.search(Entry.name == arrival['name'])
+		if len(ps) == 0:
+			print("User is not subscribed to notifications :(")
+			return "User is not subscribed to notifications :("
+
+		ps = ps[0]
+
+		print("Sending notification", arrival, ps)
+
+		subscription = ps['sub']
+		notification = {
+			'title': "Forgot to sign out?",
+			'body': "You didn't sign out of ftracker yet",
+			'arr': arrival
+		}
+
+		try:
+			webpush(
+				subscription,
+				json.dumps(notification),
+				vapid_private_key = self.vapid_creds['private_key'],
+				vapid_claims = self.vapid_creds['claims']
+			)
+			print("Notification sent")
+			return None
+		except WebPushException as exc:
+			print("Notification failed", exc)
+			return repr(exc)
+
+
+	def notify_logged_in_users(self):
+
+		print("Notifying users that aren't signed out yet...")
+
+		td = timedelta(hours=self.hours)
+
+		threshold = datetime.utcnow() - td
+
+		iso = threshold.isoformat() + 'Z'
+
+		Entry = Query()
+		arrivals = self.db.search(
+			(Entry.arrival < iso) & (Entry.departure == None)
+		)
+
+		for arrival in arrivals:
+			self.notify_user(arrival)
+
+		print("Notified everything until UTC", iso)
+
+	def __init__(self, db, hours, vapid_creds):
+
+		self.db = db
+		self.hours = hours
+		self.vapid_creds = vapid_creds
+
+		self.notify_logged_in_users()
+
+		Thread.__init__(self, daemon=True)
+		self.stopped = Event()
+		self.start()
+
+	def run(self):
+
+		while not self.stopped.wait(ONE_HOUR_IN_S):
+			self.notify_logged_in_users()
+
+	def stop(self):
+		self.stopped.set()

res/config.deploy.ini

@@ -4,6 +4,9 @@
 # Remove or leave empty for temporary (/tmp/ftracker-db.json) storage
 db_file = /var/ftracker/db.json
 
+# Delete all information after X days (e.g. for GDPR compliance)
+delete_after_days = 28
+
 # List of people to be allowed, in .csv format (comma, no delimiters)
 # Col1: First Name(s), Col2: Last Name(s), Col3 (optional): EMail
 # Remove or leave empty for no check
@@ -21,3 +24,13 @@ guideline_url = https://youtu.be/oHg5SJYRHA0
 
 # JSON indentation for debugging
 json_indent = 4
+
+# VAPID credentials for push notifications
+# private key: base64url encoded public part of an EC-Prime256v1 keypair. See INSTALL.md
+# private key: base64url encoded private part of an EC-Prime256v1 keypair. See INSTALL.md
+# sender info: usually mailto link to responsible party to contact about issues
+push_public_key = abcdefghijklm_NOPQRSTUVWXYZ-0123456789abcdefghijklm_NOPQRSTUVWXYZ-0123456789abcdefghijklm_NOPQRSTUVWXYZ-0123456789
+push_private_key = abcdefghijklm_NOPQRSTUVWXYZ-0123456789
+push_sender_info = mailto:admin@example.com
+# when to notify users, in hours after arrival
+notify_after_hrs = 10

res/docker-entrypoint.sh

@@ -1,5 +1,24 @@
 #!/bin/bash
 
+echo " >>> Checking / Creating & patching VAPID creds <<< "
+
+VAPID_CREDS_FILE=/etc/ftracker/vapid-creds.json
+if [[ ! -f $VAPID_CREDS_FILE ]]
+then
+
+	echo "Generating keypair ..."
+
+	web-push generate-vapid-keys --json > $VAPID_CREDS_FILE
+
+	echo "Patching keypair into config ..."
+	PUB_KEY=`cat $VAPID_CREDS_FILE | jq -r .publicKey`
+	echo "pushServerPublicKey = ${PUB_KEY}" >> /var/www/html/ftracker/main.js
+
+	PRIV_KEY=`cat $VAPID_CREDS_FILE | jq -r .privateKey`
+	echo "push_private_key = ${PRIV_KEY}" >> /etc/ftracker/config.ini
+
+fi
+
 echo " >>> Starting nginx <<< "
 
 mkdir /run/nginx # needed because of bug in package

setup.py

@@ -20,6 +20,7 @@ st.setup(
 		"flask",
 		"tinydb",
 		"python-slugify",
+		"pywebpush",
 	],
 	license=license_text,
 	classifiers=[

web/index.html

@@ -13,25 +13,27 @@
 				'departure': 'I have cleaned my workspace'
 			}
 			var testCheckBox = '<label class="checkbox"><input type="checkbox" name="tested" id="tested"><span>I have been tested negative for COVID in the last 24 hours</span></label>'
+			var editTimeBox = '<label>Departure Date/Time:<input type="datetime-local" name="datetime" id="datetime" required></label>'
 			function getParams() {
-				var h = document.location.href
-				var qparam = h.split('?')[1] || null
-				if (qparam == null)
-					return null
-				var vals = qparam.split('=')
-				if (vals.length < 2 || !cbt.hasOwnProperty(vals[0]))
-					return null
-				return {
-					action: vals[0],
-					room: vals[1]
+				var qparams = document.location.search.substr(1)
+				if (qparams == "") return {}
+				qparams = qparams.split('&')
+				var qps = {}
+				for (var qparam of qparams) {
+					var vals = qparam.split('=')
+					qps[vals[0]] = vals[1] || null
 				}
+				// Backwards compat
+				if (qps.arrival)   {qps.action = 'arrival';   qps.room = qps.arrival}
+				if (qps.departure) {qps.action = 'departure'; qps.room = qps.departure}
+				return qps
 			}
 			var qp = getParams()
 		</script>
 	</head>
 	<body>
 		<h1><script>
-			document.write(qp ? (qp.action + "<br>Room " + qp.room) : 'FTracker<br>V1')
+			document.write(qp.action ? (qp.action + "<br>Room " + qp.room) : 'FTracker<br>V1')
 		</script></h1>
 		<div id="startpage">
 			This is a web app to track which people
@@ -56,6 +58,10 @@
 				Full Name:<br>
 				<input type="text" name="name" id="name" placeholder="John Doe" required>
 			</label>
+			<script>
+				if (qp.edittime && qp.edittime == 1)
+					document.write(editTimeBox)
+			</script>
 			<label class="checkbox">
 				<input type="checkbox" name="agree" id="agree" required>
 				<span><script>
@@ -63,7 +69,7 @@
 				</script></span>
 			</label>
 			<script>
-				if (qp && qp.action == 'arrival')
+				if (qp.action && qp.action == 'arrival')
 					document.write(testCheckBox)
 			</script>
 			<input type="submit">

web/main.js

@@ -1,7 +1,7 @@
 var spage = document.getElementById('startpage')
 var mform = document.getElementById('mainform')
 
-if (qp) {
+if (qp.action) {
 	spage.style.display = 'none'
 	mform.style.display = 'block'
 }
@@ -12,18 +12,26 @@ if (savedName && qp)
 	document.getElementById('name').value = savedName
 
 // 2nd script, server API communication
-var name, agreed, tested
+var name, datetime, agreed, tested
 mform.onsubmit = function(e) {
 
 	e.preventDefault()
 
-	name = e.srcElement[0].value
-	agreed = e.srcElement[1].checked
-	if (e.srcElement.length > 2)
-		tested = e.srcElement[2].checked
+	var i = 0;
+	name = e.srcElement[i++].value
+	if (qp.edittime && qp.edittime == 1) {
+		var value = e.srcElement[i++].value
+		datetime = new Date(value).toISOString()
+	}
+	agreed = e.srcElement[i++].checked
+	if (qp.action && qp.action == 'arrival')
+		tested = e.srcElement[i++].checked
+
 
 	sendMainData()
 
+	initPush(name)
+
 }
 
 function sendMainData() {
@@ -33,11 +41,13 @@ function sendMainData() {
 		{
 			'room': qp.room,
 			'name': name,
+			'arrival': datetime,
 			'agreetoguidelines': agreed,
 			'tested': tested
 		} :
 		{
 			'name': name,
+			'departure': datetime,
 			'cleanedworkspace': agreed
 		}
 
@@ -159,7 +169,7 @@ function handleRequest(res) {
 				<form id="reqform">
 					<label>
 						${reqt[json.request]}
-						<input type="datetime-local" id="datetime" ${minD} max="${now}" required>
+						<input type="datetime-local" ${minD} max="${now}" required>
 						${aInfo}
 					</label>
 					${doubleT}
@@ -179,3 +189,90 @@ function handleRequest(res) {
 	})
 
 }
+
+
+if (qp.edittime && qp.edittime == 1) {
+	var now = localISOTimeMinutes(new Date())
+	document.getElementById('datetime').value = now;
+	document.getElementById('datetime').max = now;
+}
+
+
+/* Push Notifications */
+
+function sendNotification() {
+
+	navigator.serviceWorker.ready.then(function(serviceWorker) {
+		serviceWorker.showNotification("Forgot to sign out?", {
+			body: "You didn't sign out of ftracker yet",
+			icon: "/favicon.ico",
+			actions: [{
+				action: "depart",
+				title: "Sign Out"
+			}]
+		})
+	})
+
+}
+
+function initPush(name) {
+
+	// Check availability
+	var supported = "serviceWorker" in navigator && "PushManager" in window
+	if (!supported) {
+		console.warn("Push Notifications not supported!")
+		return
+	}
+
+	fetch('/pushinfo').then(function(res) {
+		if (res.ok)
+			res.json().then(function(push) {
+				if (push.enabled)
+					registerPush(name, push.publickey);
+			});
+	});
+
+}
+
+function registerPush(name, pushServerPublicKey) {
+
+	// Register service worker
+	navigator.serviceWorker.register("/sw.js").then(function(swRegistration) {
+		console.log("ServiceWorker registered:", swRegistration)
+	})
+
+	// Request permission
+	// TODO: Only do this AFTER the first? SUCCESSFUL sign-in
+	Notification.requestPermission(function(result) {
+		return (result === 'granted')
+	}).then(function(consent) {
+		console.log('Notifications', consent ? 'enabled' : 'denied');
+	})
+
+	// Check if already initialized
+	if (localStorage.getItem('pushsub'))
+		return
+
+	// Register push service
+	navigator.serviceWorker.ready.then(function(serviceWorker) {
+		serviceWorker.pushManager.subscribe({
+			userVisibleOnly: true,
+			applicationServerKey: pushServerPublicKey
+		}).then(function(subscription) {
+			console.log("User is subscribed:", subscription);
+
+			fetch('/pushsubscribe', {
+				method: "POST",
+				headers: {"Content-Type": "application/json"},
+				body: JSON.stringify({
+					name: name,
+					sub: subscription
+				})
+			}).then(function(res) {
+				if (res.ok)
+					localStorage.setItem('pushsub', subscription);
+			});
+		});
+	});
+
+}

web/sw.js

@@ -0,0 +1,35 @@
+function receivePushNotification(event) {
+
+	var data = event.data.json();
+
+	console.log("[Service Worker] Push Received:", data)
+
+	var room = data.arr ? data.arr.room : 'test'
+
+	var options = {
+		data: `/?departure=${room}&edittime=1`,
+		body: data.body,
+		icon: "/favicon.ico",
+		actions: [{
+			action: "depart",
+			title: "Sign Out"
+		}]
+	};
+
+	event.waitUntil(self.registration.showNotification(data.title, options))
+
+}
+
+self.addEventListener("push", receivePushNotification)
+
+
+function openPushNotification(event) {
+
+	console.log("[Service Worker] Notification click Received.", event.notification.data)
+
+	event.notification.close()
+	event.waitUntil(clients.openWindow(event.notification.data))
+
+}
+
+self.addEventListener("notificationclick", openPushNotification)