Deploying a Flask app

Under Gunicorn or uWSGI behind nginx, or on a PaaS: nothing realtime is kept on your servers, so any worker answers any request.

Its settings

WORDPLUS_SITE, WORDPLUS_SECRET	from your app in WordPlus Cloud
WORDPLUS_LOCAL_KEY	yours: kept as long as the app

Set them in the server environment, as you do SECRET_KEY. Keep the secret and the local key out of your repository and out of every page. The key reaches pages through config(), which is what it is for.

Its addresses

Add every address your pages are served from to the app in WordPlus Cloud: scheme, host and port exactly (https://shop.example.com, https://www.shop.example.com). A page anywhere else is refused with wrong_origin. Up to 20 addresses an app. If your server hears webhooks, set their address there too.

Its files

realtime-worker.js, realtime-rooms.min.js, realtime-rooms-e2ee.worker.js and realtime-ui.min.js are served by your app, from its own address: a browser runs a worker only from the page origin. Copy them into static/ in your build (npx wordplus-realtime copy static/), so each release serves the ones its package came with.

Workers

Every Gunicorn worker answers the realtime route, and an emit is an HTTPS request to WordPlus Cloud, done in the view. For many emits, or ones you do not want a request to wait on, send them from a task queue (Celery, RQ).

Behind a proxy

Wrap the app in the Werkzeug ProxyFix, and set SESSION_COOKIE_SECURE = True, as for any Flask app behind TLS: the realtime route uses the session.

Content Security Policy

If your pages send one, let them reach the WordPlus Cloud servers (the realtime servers, which may move a connection to another of them, and the media servers for group calls) and run the workers from your own address:

connect-src 'self' https://*.wordplus.cloud wss://*.wordplus.cloud;
worker-src 'self';

Clocks

Your server signs what it sends with the time. Keep its clock synced (NTP): one more than 5 minutes off has its emits refused with stale_signature.