How to restrict or limit a new ubuntu user from accessing other folder?

1. add a new user

sudo adduser newuser

2. add user to sudo group

sudo usermod -aG sudo newuser

3. add user to ssh group

sudo vim /etc/ssh/sshd_config

>>AllowUsers newuser

4. add restriction to the new user (space sensitive)

sudo visudo -f /etc/sudoers.d/newuser

>>newuser ALL=(ALL) ALL, !sudoedit, !/usr/bin/su, !/bin/su, !/bin/bash, !/bin/sh, !/usr/bin/chmod, !/usr/bin/chown, !/usr/bin/docker, !/usr/bin/passwd, !/usr/sbin/visudo

5. check the new restriction

sudo visudo -c

If it is ok, you will the following message print out:

/etc/sudoers: parsed OK

/etc/sudoers.d/README: parsed OK

/etc/sudoers.d/newuser: parsed OK

6. apply folder restriction to current user folder

sudo chmod -R 700 /home/currentuser

7. reboot the machine and check the restriction

sudo reboot

cd /home/currentuser

sudo chmod -R 777 /home/currentuser

sudo docker ps