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[Raspberry Pi 3] How to Change Only the Ubuntu Username Without Changing the User ID (uid)

Sat, 14 Mar 2020 20:09:17 +0900

This continues from [Raspberry Pi 3] Installing Ubuntu 18.04 LTS (No Keyboard or Display Required).
Leaving the user and password as ubuntu/ubuntu is dangerous, so this is about changing them for now.
Creating a new user and then deleting the ubuntu user would be fine too, but I tried changing only the name while keeping uid=1000 and gid=1000.

Test Environment

Raspberry Pi 3
Ubuntu 18.04.04 LTS 32-bit

How to Do It

You need to log in as root before doing the work, so it may be a little more troublesome than adding a new user and deleting the ubuntu user.

Firewall Settings on Ubuntu 19.10

Fri, 06 Dec 2019 21:14:37 +0900

Since the machine connects directly to an external network over PPPoE, I enable the firewall.

$ sudo ufw allow 80
$ sudo ufw allow 443
$ sudo ufw limit 22
$ sudo ufw enable

I exposed the web server and SSH. SSH password login was disabled beforehand.

/etc/ssh/sshd_config
PasswordAuthentication no

Check the settings with an online nmap site or similar.