On Ubuntu Server and Arch I was able to change the following line in /lib/systemd/system/getty@.service

# Before
ExecStart=-/sbin/agetty -o '-p -- \\u' --noclear %I $TERM


# After
ExecStart=-/sbin/agetty --noissue --autologin john %I $TERM Type=idle

And it works, that it will login to the user john but when I logout of the user john with using exit in the terminal, it logs john back in. Is there a way to change this ExecStart setting to enable auto login for a user on startup but only on startup?