add only sftp user to serverpilot app

add_user_sftp_serverpilot.sh

#! /bin/bash
# $1 user
# $2 from path

# prerequisites:
# create sftp-only group
# sudo groupadd sftp-only

# add sftp-only configurations
# we need to modify the ssh configuration on file /etc/ssh/sshd_config replacing the following line:
# Subsystem sftp /usr/lib/openssh/sftp-server
# to: Subsystem sftp internal-sftp
# and add in end of file:

# Match group sftp-only
#     PermitTunnel no
#     X11Forwarding no
#     AllowTcpForwarding no
#     ForceCommand internal-sftp

if test "$#" -ne 2; then
    echo "expected 2 params: {user} {from-path}"
    exit 1
fi

printf "add user $1\n"
read -n 1 -s -r -p "Press any key to continue"
printf "\n"

# create user
sudo adduser $1

# prevent ssh access
sudo usermod -s /bin/false $1

# add to server group
# (in serverpilot is "serverpilot")
sudo usermod -a -G serverpilot $1

# add sft-only group
sudo usermod -a -G sftp-only $1

# set de primary group 
sudo usermod -g serverpilot $1

printf "mounting the directory /home/$1/$(basename $2)\n"
read -n 1 -s -r -p "Press any key to continue"
printf "\n"
# create mountpoint container
sudo mkdir /home/$1/$(basename $2)
sudo chown $USER:serverpilot /home/$1/$(basename $2)
# mount the real path

sudo mount --bind $2 /home/$1/$(basename $2)

printf "add to crontab: mounting the directory /home/$1/$(basename $2)\n"
read -n 1 -s -r -p "Press any key to continue"
printf "\n"

#write out current crontab
crontab -l > /tmp/mycron
#echo new cron into cron file
echo "@reboot mount --bind $2 /home/$1/$(basename $2)" >> /tmp/mycron

#install new cron file
crontab /tmp/mycron
rm /tmp/mycron

printf "success\n"