Make sure that web resources handled by the Vaadin Servlet are available in OSGi

[denis-anisimov]

This ticket is about resources which are internally handled by the Vaadin servlet as a static resource (via StaticFileServer).
There are some internal URLs which are handled by Flow like StreamResource (their URI starts with VAADIN/dynamic/resource/) see StreamRequestHandler::generateURI .
Also VaadinServlet has logic which handles webjar URLs.
Those resources should be available as web resources in OSGi.

See mmerruko/framework@687a900 for related (but not necessary the same) support in FW8.

This will require some OSGi test environment. So it might be that this should not be done before #4227.

[denis-anisimov]

This is kind of blocked by the #4227 but it doesn't have to wait when the task will be completely done (and merged).
The #4227 should give a way to check whether an application can be used in OSGi.
At least there should be a simple way to deploy an application and check the result.
Otherwise this needs to be done every time when any OSGi related task is done and this is waste of time to reinvent the testing path every time.

[denis-anisimov]

What needs to be done: create an application, deploy it to OSGi and make sure the internal web resources are available there (webjars and internal URLs are handled properly).
If the custom way to do this is too complicated or may be improved then provide a way which can be used to simplify this in OSGi environment (see mentioned commit in FW).

[denis-anisimov]

Similar issue is #4230

[denis-anisimov]

The resolution comments for this ticket:

• webjars don't work at all with OSGi. Separate ticket for this: Webjars are not OSGi compatible #4413.
• static resource has separate issue : Make sure that static web resources are available in OSGi #4230.
  • Compiled client resources are registered via an HttpService (and so made available via HTTP).
  • Other static resources has an issue with ServletContext. It's describe in Make sure that static web resources are available in OSGi #4230.
• Dynamic internal resources functionality is tested via Templates test but there is no dedicated test for this. I will create one.

So in the result: this issue is divided to a number of sub-issues already reported.
The only remaining part here is dedicated test for dynamic resources.