example.customizer.hook.sh

#!/bin/bash
echo "HOOK: Updating package lists..."
apt update
apt list --upgradable

echo "HOOK: Enabling squid-deb-proxy-client for local network..."
apt install squid-deb-proxy-client -y

echo "HOOK: Installing git."
apt-get install -y --no-install-recommends git
echo "HOOK: Updating packages to current..."
# Work around annoying GUI recommends (fonts-droid-fallback)
apt-get install -y --no-install-recommends libgs9-common 
# Do the package upgrade to bring us to the latest package versions
# Using apt for this instead of apt-get, we get a nice progress bar for longer operations.
apt full-upgrade -y
# Clean up any extra packages from the upgrade
apt-get autoremove --purge -y

echo "HOOK: Configuring git."
git config --global user.email "user@example.com"
git config --global user.name "Local User"
git config --global push.default simple
mkdir -p /home/git/

echo "HOOK: Checking out project repository..."
cd /home/git/
git clone https://user@github.com/user/project.git --depth=1

echo "hook: Attempting to customize ISO contents..."
cd /home/git/project/buildscripts/bionic/
git pull

echo "HOOK: Running customization script..."
./00-build-ubuntu-iso-from-source.sh
apt-get autoremove --purge -y

echo "HOOK: Autobuild complete."
exit 0