Automates the conversion of traditional Linux users to systemd-homed management, preserving everything that matters - UIDs, groups, and home directories - with safety backups along the way.

move-user-to-homed.sh

#!/bin/bash

# Function to check if the script is run with sudo (root privileges)
check_root() {
    if [[ $EUID -ne 0 ]]; then
        echo "This script must be run as root (use sudo)."
        exit 1
    fi
}

# Function to display help message
show_help() {
    echo "This script automates the process of converting a traditional user account to a systemd-homed managed user."
    echo "It also supports adding additional arguments for shell, timezone, language, and other customizations."
    echo ""
    echo "Usage:"
    echo "  sudo ./convert_to_homed.sh <username> [--shell=<shell>] [--timezone=<timezone>] [--language=<language>] [additional arguments]"
    echo "  sudo ./convert_to_homed.sh --help           - Displays this help message."
    exit 0
}

# Function to convert an existing user to systemd-homed managed user
convert_user() {
    local username=$1
    shift  # Remove the username from the arguments to handle other arguments

    local user_home="/home/$username"
    local user_home_backup="/home/$username.saved"

    # Check if the user exists
    if ! getent passwd "$username" > /dev/null; then
        echo "Error: User '$username' does not exist."
        exit 1
    fi

    # Backup the current home directory
    echo "Backing up the home directory for $username..."
    mv "$user_home" "$user_home_backup" || { echo "Failed to move home directory."; exit 1; }

    # Get user details
    user_details=$(getent passwd "$username")
    user_uid=$(echo "$user_details" | cut -d: -f3)  # UID
    user_gecos=$(echo "$user_details" | cut -d: -f5)  # GECOS field
    user_gid=$(echo "$user_details" | cut -d: -f4)  # GID

    # Get the group name for the user
    user_group=$(getent group "$user_gid" | cut -d: -f1)

    echo "User details for $username: UID=$user_uid, GECOS=$user_gecos, GID=$user_gid, Group=$user_group"

    # Get all groups the user is a part of
    user_groups=$(id -Gn "$username" | tr ' ' ',')  # Convert space-separated list to comma-separated

    # Check for optional arguments like shell, timezone, and language
    user_shell=""
    user_timezone=""
    user_language=""

    while [[ $# -gt 0 ]]; do
        case "$1" in
            --shell=*)
                user_shell="${1#*=}"
                shift
                ;;
            --timezone=*)
                user_timezone="${1#*=}"
                shift
                ;;
            --language=*)
                user_language="${1#*=}"
                shift
                ;;
            *)
                echo "Unknown argument: $1"
                shift
                ;;
        esac
    done

    # Remove the user entry from /etc/passwd, /etc/shadow, and /etc/group
    echo "Removing the old user account from /etc/passwd, /etc/shadow, and /etc/group..."
    vipw -s -u "$username" && vipw -s -g "$user_group" && vigr -s -g "$user_group" && vigr -s -u "$username"

    # Create the systemd-homed user with the same UID and GECOS, and include user groups
    echo "Creating the systemd-homed user $username..."
    homectl create "$username" --uid="$user_uid" --real-name="$user_gecos" --member-of="$user_groups" \
        ${user_shell:+--shell="$user_shell"} \
        ${user_timezone:+--timezone="$user_timezone"} \
        ${user_language:+--language="$user_language"} || { echo "Failed to create homed user."; exit 1; }

    # Migrate the old home directory to the new systemd-homed user directory
    echo "Migrating the old home directory..."
    homectl with "$username" -- rsync -aHANUXv --remove-source-files "$user_home_backup/" /home/"$username" || { echo "Failed to migrate home directory."; exit 1; }

    # Clean up the old home directory backup
    echo "Removing old home directory backup..."
    rmdir "$user_home_backup" || { echo "Failed to remove backup directory."; exit 1; }

    # Restart NetworkManager for any changes to take effect
    echo "Restarting NetworkManager..."
    systemctl restart NetworkManager
    echo "User '$username' has been successfully converted to a systemd-homed managed user!"
}

# Main logic of the script
check_root  # Ensure the script is run with root privileges

# Handle arguments
if [[ "$1" == "--help" ]]; then
    show_help  # Display help message and exit
fi

# Ensure a username is provided
if [[ -z "$1" ]]; then
    echo "Error: You must provide a username to convert to systemd-homed."
    exit 1
fi

# Convert the user to systemd-homed
convert_user "$@"