scripts/shell/chroot-rescue

#!/usr/bin/env bash
# This script will mount and chroot a linux system
# Copyright 2024 Bryan C. Roessler

lsblk

# Set defaults
RP=${ROOT_PART:-/dev/nvme0n0p3}
BP=${BOOT_PART:-/dev/nvme0n0p1}

echo "Press enter to accept default value"
read -r -p "Root partition [$RP]: " RP
read -r -p "Boot partition [$BP]: " BP
MD="${MOUNT_DIR:-/mnt/${RP##*/}}"
[[ -d $MD ]] && MD=$MD-$RANDOM
read -r -p "Mount directory [$MD]: " MD

[[ -e $RP && -e $BP ]] || exit 1

# Mount and entire the chroot
echo "Mounting and entering chroot"
sudo mkdir -p "$MD" &&
sudo mount "$RP" "$MD" &&
for i in proc sys dev; do
  sudo mount --bind /$i "$MD/$i"
done &&
sudo mount "$BP" "$MD/boot/efi" &&
sudo chroot "$MD";

# After chroot
echo "Exiting and unmounting chroot"
sudo umount "$MD/boot/efi"
for i in proc sys dev; do
  sudo umount "$MD/$i"
done 
sudo umount "$MD"

exit $?