Linux

Add sudoer

useradd -d /home/my_user -m -U -G sudo my_user

nano /etc/passwd
# Reaplce `my_user:x:1000:1000::/home/my_user:/bin/sh`
# with `my_user:x:1000:1000::/home/my_user:/bin/bash`

visudo
# Replace `%sudo   ALL=(ALL:ALL) ALL`
# with `%sudo   ALL=(ALL:ALL) NOPASSWD: ALL`

Disable ssh password auth

nano /etc/ssh/sshd_config

# Replace `#PasswordAuthentication yes`
# with `PasswordAuthentication no`

Remote rsync with login and password

# For RSA key fingerprint
ssh {login}@{ip/host}

sshpass -p '{secret}' rsync --progress --ignore-errors -azqKL \
    -e ssh {user}@{ip/host}:/var/www/remote/* /var/www/guest