acts as FTP proxy forward all FTP connection from clients to FTP server
using tcp_proxy filter chain
using prometheus for monitoring
FTP server
works as FTP server
using pam_url plugins to send(POST method) authenticated FTP request login to flask API for authentication
using pam_script plugin to create a folder for client after successfully authentication
vsftpd has a definition virtual users, what is virtual users
The user is not working on the OS system level
The user is only meaning with ftp account
Nginx server
acts as web reverse proxy for caching authenticatons for flask API
Flask framework
acts as API web server
Flask routes
```ss
Endpoint Methods Rule
-------------- ------- -----------------------
account.check POST /account/check
account.create POST /account/create
account.delete POST /account/delete
account.index GET /account/
static GET /static/