bootstrap.sh

#!/usr/bin/env bash

set -euo pipefail

### Packages, kernel, systemd ###

# Fix cloudflare postrm
if [[ -f /var/lib/dpkg/info/cloudflared.postrm ]]; then
  cat <<-EOF > /var/lib/dpkg/info/cloudflared.postrm
  #!/bin/bash
  set -eu
  rm -f /usr/local/bin/cloudflared
  rm -f /usr/local/etc/cloudflared/.installedFromPackageManager || true
EOF
fi

# Stop cloudflared and jupyter units
systemctl disable --now cloudflared.service cloudflared-update.{service,timer} lambda-jupyter.service || true

# Get current cloud image manifest
wget https://cloud-images.ubuntu.com/jammy/current/jammy-server-cloudimg-amd64.manifest -O /tmp/manifest

# Automated interactions
export DEBIAN_FRONTEND=noninteractive

# Extract differences in installed packages
comm -23 <(dpkg --get-selections | awk '{print $1}; F=":" {print $1}' | sort) <(awk '{print $1}; F=":" {print $1}' /tmp/manifest | sort) > /tmp/extra-packages

# Purge extras
xargs apt autoremove --purge -y < /tmp/extra-packages

# Purge old kernels
apt autoremove --purge -y linux-*-5* linux-*-6*

# Purge apparmor and snap
apt autoremove --purge -y apparmor snapd

# Remove 3rd party repos
rm -f /etc/apt/{cloud-init.gpg.d,sources.list.d}/*

# Remove custom services
rm -f /etc/systemd/system/cloudflared*
rm -f /etc/systemd/system/lambda-jupyter*

# Update repos
apt update

# Install latest HWE kernel
apt install --no-install-recommends -y linux-image-generic-hwe-22.04

# Upgrade rest of system
apt upgrade -y

# Disable apparmor in kernel
sed -i 's/GRUB_CMDLINE_LINUX=""/GRUB_CMDLINE_LINUX="apparmor=0"/' /etc/default/grub
update-grub

### Fixup networking ###

public_ip() {
  # Strip CIDR
  address=${1%/*}

  # Check RFC1918 space
  if [[ "$address" =~ ^10\.|^172\.(1[6-9]|2[0-9]|3[0-1])\.|^192\.168\. ]]; then
    return 1 # Private
  else
    return 0 # Public
  fi
}

NETWORK_FILE=/etc/systemd/network/20-wired.network

# Grab addresses from network definition
for address in $(grep ^Address= $NETWORK_FILE); do
  # Strip Address= prefix
  if public_ip ${address/Address=/}; then
    # Delete from network file
    sed -i "/Address=$address/d" $NETWORK_FILE
  fi
done

### Miscellaneous ###

# Cleanup ubuntu user
rm -rf /home/ubuntu/.{local,cache,jupyter,ipython}

### Finished ###

# Reboot
reboot