This script automates the process of entering a chroot environment.

chroot_assist.sh

#!/bin/bash

: '
Interactive Chroot Script

This script automates the process of entering a chroot environment. It lists available disks and partitions,
prompts the user to select a partition, mounts the necessary filesystems, and enters the chroot environment.
The script also provides a command (`exit-chroot`) to trigger the unmounting of filesystems and exit the script.

Functions:
- list_disks: Lists available disks and partitions using lsblk.
- select_partition: Prompts the user to select a partition to chroot into and validates the input.
- mount_filesystems: Mounts the target partition and binds /dev, /dev/pts, /proc, /sys, and /run to the chroot environment.
- unmount_filesystems: Unmounts the filesystems and exits the script.
- enter_chroot: Enters the chroot environment.
- key_monitor: Monitors for the specific command `exit-chroot` to trigger unmounting.

Usage:
- Run the script as root to ensure it has the necessary privileges.
- Follow the prompts to select a partition.
- Type `exit-chroot` at any time to unmount the filesystems and exit the script.
'

# Function to list available disks and partitions
list_disks() {
    echo "Available disks and partitions:"
    lsblk
}

# Function to prompt the user to select a partition
select_partition() {
    echo "Enter the partition to chroot into (e.g., /dev/sda1):"
    read TARGET_PARTITION
    if [ ! -b "$TARGET_PARTITION" ]; then
        echo "Error: Invalid partition. Please try again."
        select_partition
    fi
}

# Function to mount necessary filesystems
mount_filesystems() {
    echo "Mounting filesystems..."
    sudo mount $TARGET_PARTITION $MOUNT_POINT && echo "Mounted $TARGET_PARTITION on $MOUNT_POINT"
    sudo mount --bind /dev $MOUNT_POINT/dev && echo "Mounted /dev on $MOUNT_POINT/dev"
    sudo mount --bind /dev/pts $MOUNT_POINT/dev/pts && echo "Mounted /dev/pts on $MOUNT_POINT/dev/pts"
    sudo mount --bind /proc $MOUNT_POINT/proc && echo "Mounted /proc on $MOUNT_POINT/proc"
    sudo mount --bind /sys $MOUNT_POINT/sys && echo "Mounted /sys on $MOUNT_POINT/sys"
    sudo mount --bind /run $MOUNT_POINT/run && echo "Mounted /run on $MOUNT_POINT/run"
    echo "Filesystems mounted."
}

# Function to unmount filesystems
unmount_filesystems() {
    echo "Unmounting filesystems..."
    sudo umount $MOUNT_POINT/dev/pts && echo "Unmounted $MOUNT_POINT/dev/pts"
    sudo umount $MOUNT_POINT/dev && echo "Unmounted $MOUNT_POINT/dev"
    sudo umount $MOUNT_POINT/proc && echo "Unmounted $MOUNT_POINT/proc"
    sudo umount $MOUNT_POINT/sys && echo "Unmounted $MOUNT_POINT/sys"
    sudo umount $MOUNT_POINT/run && echo "Unmounted $MOUNT_POINT/run"
    sudo umount $MOUNT_POINT && echo "Unmounted $MOUNT_POINT"
    echo "Filesystems unmounted."
    exit 0
}

# Function to enter chroot environment
enter_chroot() {
    echo "Entering chroot environment..."
    sudo chroot $MOUNT_POINT /bin/bash
}

# Function to handle unmount command
command_monitor() {
    while true; do
        echo "Type 'exit-chroot' to unmount and exit."
        read -p "> " cmd
        if [[ $cmd == "exit-chroot" ]]; then
            echo "Unmounting triggered by user command."
            unmount_filesystems
        fi
    done
}

# Check if the script is being run with root privileges
if [ "$EUID" -ne 0 ]; then
    echo "Please run as root"
    exit
fi

# Define the mount point
MOUNT_POINT="/mnt"

# List disks and prompt user to select a partition
list_disks
select_partition

# Mount filesystems
mount_filesystems

# Start command monitor in background
command_monitor &

# Enter chroot environment
enter_chroot

# Unmount filesystems after exiting chroot
unmount_filesystems