RaspberryPi after-first-boot config shell script

pi_init.sh

#!/bin/bash

# If you wish to have the pi change its default hostname from 'raspberrypi',
# pass the new hostname as an argument, ie:
# /boot/init.sh urmomspi

# Change these values for your environment, or set them to empty strings
# to leave at the default
LOCALE="en_US.UTF-8"
KEYB_LAYOUT="us"
TIMEZONE="America/Chicago"

# =========

if [ -n "$1" ]; then
	echo "Setting hostname to $1"
	sed -i "/^127.0.1.1\s*raspberrypi/s/raspberrypi/$1/" /etc/hosts
	echo "$1" > /etc/hostname
	touch /var/run/reboot-required
else
	echo "No hostname provided, skipping"
fi

if [ -n "$LOCALE" ]; then
	echo "Setting locale..."
	sed -i "/^# $LOCALE/s/^#\s*//" /etc/locale.gen
	locale-gen $LOCALE
	update-locale $LOCALE
fi

if [ -n "$KEYB_LAYOUT" ]; then
	echo "Setting keyboard layout..."
	sed -i "/^XKBLAYOUT=.*/c XKBLAYOUT=\"$KEYB_LAYOUT\"" /etc/default/keyboard
fi

if [ -n "$TIMEZONE" ]; then
	echo "Setting timezone"
	rm -fv /etc/localtime
	ln -sv /usr/share/zoneinfo/$TIMEZONE /etc/localtime
fi

if [ -e /boot/id_rsa.pub ]; then
	echo "Copying public key to pi user..."
	if [ ! -d ~pi/.ssh ]; then
		mkdir ~pi/.ssh
		chown pi:pi ~pi/.ssh
	fi

	cat /boot/id_rsa.pub >> ~pi/.ssh/authorized_keys
	chown pi:pi ~pi/.ssh/authorized_keys
	rm /boot/id_rsa.pub
else
	echo "No public key found at /boot/id_rsa.pub, skipping"
fi

# Stop Microsoft from getting installed
echo "Excising microsoft"
cat /dev/null > /etc/apt/sources.list.d/vscode.list
cat /dev/null > /etc/apt/trusted.gpg.d/microsoft.gpg
# Prevent future Raspbian upgrades from re-populating the microsoft repo config
chattr +i /etc/apt/sources.list.d/vscode.list /etc/apt/trusted.gpg.d/microsoft.gpg

apt-get update

echo "Installing vim and friend"
apt-get -y install vim pcregrep

echo "Installing python env tools"
apt-get -y install python3-pip python3-setuptools

echo "Running updates, this may take a while"
apt-get -y upgrade
# If an upgrade actually happened, mark reboot
pcregrep -qM 'apt-get.*upgrade(\n|.)*^Upgrade:' /var/log/apt/history.log && touch /var/run/reboot-required


if [ -e /var/run/reboot-required ]; then
	shutdown -r 6 "completing initial setup"
fi

not sure exactly when, but somewhere along the way the US locale string in /etc/locale.gen changed from en_US.UTF8 to en_US.UTF-8. Updated the script to match.