Use bjoern instead of uwsgi for lower resource usage

[neuhaus]

Since Otterwiki targets small installs, have you considered using bjoern instead of uwsgi?
It should be fast and need less RAM.

[redimp]

Hey @neuhaus! Thanks for suggesting bjoern, never heard of it before.

Currently I'm considering to remove nginx (and rendered unnecessary supervisord) from the image. This is discussed in #121.

The otterwiki:2.x.y-slim images works in this way, see Dockerfile.slim for the details.

Without nginx, the WSGI server used must be able to serve static files efficiently, which uwsgi can do amazingly well according to my benchmarks. This feature is not supported by bjoern, as far as I have seen. Serving the static files via Flask is unfortunately far too inefficient to be considered.

[neuhaus]

Another solution would be to provide all static files in a volume so nginx can serve them, even when it's not in the container.
Most users will probably need nginx in order to provide more than one service per virtual host.