Chrooty Setup Script

This script is designed to help you set up a rescue environment in Linux by mounting necessary partitions and creating a chroot environment with just a blink of an eye ;).

It is intended for recovery operations where you need to repair or troubleshoot a system from a live environment (e.g., live USB).

Key Points:

• The script is designed for rescue operations where you may need to mount partitions and set up a chroot environment for system repair.
• The root check ensures that the script is executed with the necessary privileges.
• The script allows users to easily mount system and UEFI partitions and bind the necessary directories for recovery tasks.
• The user interaction makes it easy to choose partitions while also providing feedback messages for smooth execution.

Features

• Root Check: Ensures the script is run as root before proceeding.
• Chroot Folder Setup: Verifies if the /rescue folder exists. If it doesn't, the script will create it.
• Partition Selection: Lets the user select the system partition and UEFI partition (if available). If a UEFI partition is not selected, the system partition will be used for the rescue environment.
• Mounting Partitions: Mounts the system partition and optional UEFI partition to set up the chroot environment.
• Bind Mounts: Binds critical system directories (/dev, /sys, /proc, /run, and /etc/resolv.conf) into the chroot environment for full system access.
• Unmount Cleanup: Safely unmounts all previous bind mounts from the chroot environment when done.

Requirements

The script must be executed with root privileges. Available partitions for mounting (system and optionally UEFI) must exist.

Usage

Open a terminal. Run the script as root (you can either use sudo or switch to the root user):

sudo ./rescue_setup.sh

The script will check if it's running as root. If not, it will exit with an error message.

Workflow

Root Check: The script first ensures it’s being run as root. If not, it exits immediately.

if [[ "$EUID" -ne 0 ]]; then
  echo "This script must be run as root. Exiting."
  exit 1
fi

Chroot Folder Check: The script checks if the /rescue folder exists:

If the folder doesn't exist, it will create it (mkdir -p /rescue). If the folder exists, it will confirm this and proceed.

if [[ ! -d "$rsfolder" ]]; then
  mkdir -p /rescue
fi

Partition Selection: The script will display all available disks and partitions using lsblk and ask the user to select:

System Partition: This partition is required. UEFI Partition: If a UEFI partition exists, it can be selected. If not, you can skip it.

Example:

lsblk -o NAME,SIZE,TYPE,MOUNTPOINT

Mount Partitions:

If a UEFI partition is selected, it will be mounted to /rescue/boot/efi. The system partition is mounted to /rescue.

The script mounts the partitions using the mount command:

mount "$uefi_partition" $rsfolder/boot/efi
mount "$system_partition" $rsfolder

Bind Mount Filesystems: The script binds critical directories (/dev, /sys, /proc, /run, and /etc/resolv.conf) into the chroot environment:

mount --bind /dev $rsfolder/dev
mount --bind /sys $rsfolder/sys
mount --bind /proc $rsfolder/proc
mount --bind /run $rsfolder/run
mount --bind /etc/resolv.conf $rsfolder/etc/resolv.conf

Unmount Cleanup: Once the operations are completed, the script unmounts all the bind-mounted directories:

umount $rsfolder/dev/pts || true
umount $rsfolder/dev || true
umount $rsfolder/sys || true
umount $rsfolder/proc || true
umount $rsfolder/run || true
umount $rsfolder/etc/resolv.conf || true

Completion: After successfully setting up the chroot environment - entered chroot and left, the script prints a success message and exits.

echo "Chroot environment has been cleaned up successfully."

Troubleshooting

• Error: "System partition is required!" This message appears if no system partition is selected. Please make sure you select the correct partition when prompted.

• Error: "Failed to mount partition" This error may occur if the partition is not valid or the mount point is already in use. Ensure that the partitions are not already mounted.

License

This script is open-source and free to use and under AGPL 3 licensed. Contributions and improvements are welcome!