To find out whether a user exists or not in a Linux machine: * grep username /etc/passwd or * id username To give a new user access to Linux machine: 1. Login as root user 2. Run this: $ /usr/sbin/adduser new_user 3. Set a new password: $ passwd new_user (and put the password when prompted) To give them root access: 4. Edit the /etc/sudoers file $ vi /etc/sudoers User_Alias YOUR_GROUP = new_user YOUR_GROUP ALL=(ALL) NOPASSWD: ALL To test whether the new_user has been granted root access, run these two commands: $ su new_user (user should be 'new_user' now) $ sudo su (user should be 'root' now) If the conditions above met, then new_user has root access. If the new_user want to use public/private key gen authorization: 5. Change your user to be the new_user $ su new_user 6. Create ~/.ssh/authorized_keys file if it doesn't exist yet $ mkdir ~/.ssh $ chmod 700 ~/.ssh 7. Insert the public key on the authorized_keys
A collection of my rambling thoughts that just need to be put down somewhere