Notification system add to user demo

[llarsson]

@cristiklein and I discussed that we, from time to time, get customer requests for how to do app and web page notifications in the browser.

While it sounds simple enough, it is not at all obvious how one does that, given the Ingress that is in the way, and whether support for web sockets is readily available, etc.

Time permitting, we could update the demo application so that it pushes out events to clients using some popular notification API.

This task requires investigating how all this stuff works, what libraries are out there, and how we can make it all work nicely in Compliant Kubernetes. So it's quite a feat!

[cristiklein]

@llarsson The team has asked for adding more context to issues they work on. Can you edit the issue to add context here?

[llarsson]

Thanks, CK! Yeah, this came out of one of our meetings and none of us filled in the details about what we discussed. :joy:

[cristiklein]

So, "notifications" can mean two things:

1. That annoying thing where a web page or app buzzes you, although the web page or app itself is closed.
2. That useful things where the web page or app is updated real-time, as determined by the server.

No 1 works via the Push API and does not need anything special from the Ingress. In fact, the "magic" happens in the backend, which needs to talk to a push service. Push services are hard-coded in the browser's code. Google Chrome has theirs and Mozilla has theirs.

No 2 would, indeed, work via WebSockets which works out-of-the-box with the Ingress Controller we use.

Anything else we need to investigate @llarsson ?

[llarsson]

This was not about an investigation, but rather, it would be about coding the second option.

Requests from this have slowed down, so I wouldn't prioritize it very highly.