Flash using the Raspberry Pi Imager – don't forget to click into the settings cog and adjust things like username/password, host IP etc, and turn on SSH (don't bother with writing a blank ssh file to the boot partition).
nmap -sP 10.0.0.0/24 is fairly reliable.
The default user (which can now be named slack comes with: slack adm dialout cdrom sudo audio video plugdev games users input render netdev gpio i2c spi. So I don't think any groups need adding. (See buster page if needed.)
Set up a root user that can be logged in to, starting with sudo su then passwd.
Pi-hole arranges/messes with this, so if you're installing that maybe set the IP address that way.
If not, then change /etc/dhcpcd.conf:
# Example static IP configuration: interface eth0 static ip_address=10.0.0.7/24 #static ip6_address=fd51:42f8:caae:d92e::ff/64 static routers=10.0.0.2 static domain_name_servers=8.8.8.8 8.8.4.4
[Shouldn't be necessary:] To set the hostname, use hostnamectl set-hostname walter,
Fix up /etc/hosts.
I guess, like, reboot to bring that up?
Raspbian contains more packages than Debian net install it seems.
[Starting from the “full” desktop install but pitched at headless]
apt install screen zsh gem install pry awesome_print
ln -s /sys/bus/w1/devices /home/slack/w1
As buster.
Copy over authorized_keys from alan.
ssh-keygen -t rsa -b 4096 -C slack-np@walter
Copy id_rsa.pub into any authosized_keys as needed.