Information from shellhacks.com.
The following command recursively downloads your site with all its files and folders from FTP server and saves them to the current directory.
|ftp.server.com||IP address or domain name of an FTP server|
|-l||Maximum recursion depth (0 = unlimit) (default = 5)|
|-nH||Disable generation of host-prefixed directories|
|-X||exclude a list of directories|
Now you can compress the folder with your site as follows:
Install pluxml on raspberry pi
I am using nginx + php7 + pluxml followinf these two links: