#!/usr/bin/env bash
set -euo pipefail

DISK="${DISK:-/dev/sda}"
PARTITION_NUMBER="${PARTITION_NUMBER:-3}"
PARTITION="${PARTITION:-${DISK}${PARTITION_NUMBER}}"
LV_PATH="${LV_PATH:-/dev/ubuntu-vg/ubuntu-lv}"

if [ "$(id -u)" -ne 0 ]; then
  echo "This script must run as root. Use: sudo $0" >&2
  exit 1
fi

echo "Before:"
lsblk -o NAME,SIZE,TYPE,FSTYPE,MOUNTPOINTS "$DISK"
df -h /
pvs
vgs
lvs

echo "Growing partition ${PARTITION} to fill ${DISK}..."
growpart "$DISK" "$PARTITION_NUMBER"

echo "Resizing LVM physical volume ${PARTITION}..."
pvresize "$PARTITION"

echo "Extending ${LV_PATH} to all free VG space and resizing filesystem..."
lvextend -l +100%FREE -r "$LV_PATH"

echo "After:"
lsblk -o NAME,SIZE,TYPE,FSTYPE,MOUNTPOINTS "$DISK"
df -h /
pvs
vgs
lvs