Add Auth example to docs

[philippjfr]

In bokeh 1.4 authentication was added to the bokeh server. We should explore how this works and provide an example in the panel docs.

[MarcSkovMadsen]

I would really, really like to know more about it. Would it be possible for you @philippjfr to just write down a brainstorm of your thoughts below? Spend maybe 5 minutes and throw in a link to where I should get started?

My use case is authentication via Azure AD. I now have a basic understanding and a working Flask example. Would like to translate to a Tornado/ Panel example.

I will be doing it for work. But when I get the time I would share the knowledge somehow to the Panel community.

[MarcSkovMadsen]

Ok. I found some Bokeh sample code on authentication - not for Azure AD though. I have a poc for Azure AD and Bokeh working now.

[MarcSkovMadsen]

I'm starting with Panel example now. I can see that the bokeh authentication mechanism runs when I use panel serve with panel.servable

But when I use python with panel.serve or my_app.show() the auth module and get_user function is not run.

I.e. authentication in Panel seems to work only with the panel.servable way of launching the application. Which is not good for my use cases.

[MarcSkovMadsen]

@philippjfr . Where could I find information on how to hook up authentication when I use panel.serve or my_app.show()? It is not working (for me at least). See above comment.

[MarcSkovMadsen]

A stackoverflow question from a user regarding Panel+Flask auth. Maybe that should be added to the documentation as well

https://stackoverflow.com/questions/60169875/handling-user-authentication-in-flask-bokeh-panel-setup

[philippjfr]

So currently I was just considering adding OAuth plugins as I started to do in this PR: #820

That said if there are other auth solutions we should consider shipping with Panel we should probably do so.

Where could I find information on how to hook up authentication when I use panel.serve or my_app.show()?

Basically you just provide an auth_provider as a keyword argument to the show command and or you could work up a PR to add auth handling equivalent to this code in bokeh directly to the get_server utility in Panel.

[philippjfr]

There is now a section on Auth providers: https://pyviz-dev.github.io/panel/user_guide/Authentication.html