a demo for web push (service worker, pwa)

• a VAPID includes a public key and a private key;
• server: check if there is already a VAPID, otherwise generates it;
• browser: check if there is already a subscription, otherwise get publickey from server;
• browser: subscribe to FCM, get endpoint info;
• browser: send endpoint info and other info (userid, for example) to the server;
• server: send endpoint info to the FCM and browser get a push;

  git clone
  npm i
  npm start

• open localhost:3000 subscribe
• close chrome tab and reopen localhost:3000, let the service worker take control of the page
• open localhost:3000/admin.html , send a update resource push
• when the client localhost:3000 get the push, it will get /push-log resource and update it automatically

• google service framework is needed if you want to run it in an Android devices;
• a scientifically network is needed. You should be able to access FCM;

• https://gauntface.github.io/simple-push-demo/
• google Docs