Speed up serving static files by serving them through ngnix and not application

[michaelwood]

Serving the files via gunicorn is much slower than directly from the web server/ngnix

We optimised this in insights-ng. See example in insights-ng:

insights salt file:

dokku storage:ensure-directory insights_static
dokku storage:mount insights-ng /var/lib/dokku/data/storage/insights_static:/insights_static

insights_ngnix_static_conf:
  file.managed:
    - name: /home/dokku/insights/nginx.conf.d/static.conf
    - source: salt://nginx/insights_static.conf
    - require:
      - cmd: insights_create_app

static.conf:

location /static/ {
  alias /var/lib/dokku/data/storage/insights_static/;
}