[-] The primary server API is exposed via Flask (Python) and all static files, including all html, css, js is served by nginx.
[-] Python is exposing an API at url http://domain.com/api/download/<file_id>, where file_id is a database id for the file that we're interested in downloading.
1. User wants to download a file, so we spawn a new window with the url '/api/download/<file_id>'
2. Nginx intercepts the request, sees that it starts with /api/, and then forwards the request to Flask, which is being served on port 5000.
3. Flask routes the request to its download method, retrieves the pertinent data from the file_id, and constructs additional header settings to make nginx happy and to force the browser to see the file stream as a download request instead of the browser just trying to open the file in a new window. Flask then returns the modified header stream to nginx
4. Nginx is finally ready to do some work. While parsing the headers for the incoming request, it encounters "X-Accel-Redirect", which instructs nginx to serve the file specified
5. The browser should spawn a download dialog box, but instead it just spawns a new window that contains, as text, the binary contents of the file...