Move VAPID public key config to backend for easier config

Also enables the frontend not asking for notiffication permission if it
doesn't need them.
Should also help if it ever needs to be changed to circumvent cache.

INSTALL.md

@@ -187,10 +187,10 @@ sudo npm install -g web-push
 web-push generate-vapid-keys
 ```
 
-The public Key needs to be copied into `web/main.js` (first line), while the
+The keys then need to be copied into the config options `push_public_key` and
-private key is put into the config option `push_private_key`.
+`push_private_key` respectively so the backend can handle the rest.
 
-Then, to be VAPID compliant you have to announce an contact address claim to
+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`.

config.ini

@@ -26,8 +26,10 @@ guideline_url = https://fasttube.de/wp-content/uploads/2020/12/Cororna-Regeln-St
 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

ftracker/core.py

@@ -171,6 +171,25 @@ 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():
 

res/config.deploy.ini

@@ -26,8 +26,10 @@ guideline_url = https://youtu.be/oHg5SJYRHA0
 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

res/docker-entrypoint.sh

@@ -10,11 +10,10 @@ then
 
 	web-push generate-vapid-keys --json > $VAPID_CREDS_FILE
 
-	echo "Patching public key into frontend ..."
+	echo "Patching keypair into config ..."
 	PUB_KEY=`cat $VAPID_CREDS_FILE | jq -r .publicKey`
-	sed -i "s/pushServerPublicKey = '[a-zA-Z0-9_\-]*'/pushServerPublicKey = '${PUB_KEY}'/" /var/www/html/ftracker/main.js
+	echo "pushServerPublicKey = ${PUB_KEY}" >> /var/www/html/ftracker/main.js
 
-	echo "Patching private key into backend config ..."
 	PRIV_KEY=`cat $VAPID_CREDS_FILE | jq -r .privateKey`
 	echo "push_private_key = ${PRIV_KEY}" >> /etc/ftracker/config.ini
 

web/main.js

@@ -1,5 +1,3 @@
-var pushServerPublicKey = 'BBwBPYxhogHLU3B1FpxfQNzO3q7qZpmD1n1KaaL8WJbcVmJSHhi1uB-VmvsVjjUHWYCeqKyLT7w-1LBfpIcbbcg'
-
 var spage = document.getElementById('startpage')
 var mform = document.getElementById('mainform')
 
@@ -226,6 +224,18 @@ function initPush(name) {
 		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)