Scavenger Hunt

#!/usr/bin/env bash

# Ubuntu Scavenger Hunt seeder

# Creates folders, flags, and light config to support the hunt.

# Safe to re-run; will not clobber existing student work.

set -euo pipefail

### --- Config (feel free to change) ---

FLAG1="FLAG{I_AM_HERE}"                    # Task 1 flag revealed via pwd alias

FLAG2="FLAG{HIDDEN_IN_PLAIN_SIGHT}"        # Task 2 flag inside .readme

BIRD="ROBIN"                                # Task 4 bird folder/file name

CREATE_LABMATE=true                         # Task 7: create a 'labmate' user

LABMATE_SHELL="/bin/bash"

APT_PACKAGES=(tree htop nginx lsb-release)  # Tools for tasks 4,5,10 & info

TEACHER_NOTE="~/.scavenger_teacher_notes.txt"

### ------------------------------------

# Detect distro (best-effort)

if ! command -v lsb_release >/dev/null 2>&1; then

  echo "[*] Installing lsb-release for distro detection (requires sudo)..."

  sudo apt-get update -y

  sudo apt-get install -y lsb-release

fi

DISTRO="$(lsb_release -sd || echo Ubuntu)"

echo "[*] Detected: $DISTRO"

# Ensure bashrc exists

touch "${HOME}/.bashrc"

echo "[*] Creating hunt directories..."

mkdir -p "${HOME}/hunt/level1"

# --- Task 1 seed: show a flag when students run `pwd` ---

# We drop a file and lightly alias pwd to print it after the real path.

echo "$FLAG1" > "${HOME}/.whereami.flag"

if ! grep -q "SCAV_HUNT_PWD_ALIAS" "${HOME}/.bashrc"; then

  cat >> "${HOME}/.bashrc" <<'EOF'

# SCAV_HUNT_PWD_ALIAS: show a tiny hint/flag once per shell when running `pwd`

if [ -f "$HOME/.whereami.flag" ]; then

  # Avoid double aliasing if re-sourced

  if ! alias pwd 2>/dev/null | grep -q 'builtin pwd'; then

    alias pwd='builtin pwd; [ -f "$HOME/.whereami.flag" ] && cat "$HOME/.whereami.flag"'

  fi

fi

EOF

  echo "[*] Added pwd alias to ~/.bashrc (reload terminal to activate)."

else

  echo "[*] pwd alias already present."

fi

# --- Task 2 seed: hidden .readme with a flag ---

if [ ! -f "${HOME}/hunt/level1/.readme" ]; then

  echo "Welcome to the hunt! ${FLAG2}" > "${HOME}/hunt/level1/.readme"

  echo "[*] Seeded ${HOME}/hunt/level1/.readme with flag."

else

  echo "[*] ${HOME}/hunt/level1/.readme already exists (skipping)."

fi

# --- Task 4 seed: bird-named item students will see in `tree ~` ---

if [ ! -d "${HOME}/${BIRD}_notes" ] && [ ! -f "${HOME}/${BIRD}.txt" ]; then

  mkdir -p "${HOME}/${BIRD}_notes"

  echo "You found the ${BIRD}!" > "${HOME}/${BIRD}_notes/hello.txt"

  echo "[*] Created ${HOME}/${BIRD}_notes/ (flag is BIRD name: ${BIRD})."

else

  echo "[*] Bird item already present (skipping)."

fi

# --- Install packages for tasks (tree/nginx/etc.) ---

echo "[*] Installing required packages (sudo)..."

export DEBIAN_FRONTEND=noninteractive

sudo apt-get update -y

sudo apt-get install -y "${APT_PACKAGES[@]}"

# --- Task 5 prep: ensure nginx runs, but let students create clue.txt themselves ---

echo "[*] Ensuring nginx is installed. Starting service (sudo)..."

sudo systemctl daemon-reload || true

sudo systemctl enable nginx >/dev/null 2>&1 || true

sudo systemctl start nginx || true

# Create a default index if missing (harmless)

if [ ! -f /var/www/html/index.nginx-debian.html ] && [ ! -f /var/www/html/index.html ]; then

  echo "<h1>Ubuntu Scavenger Hunt</h1><p>Nginx is running.</p>" | sudo tee /var/www/html/index.html >/dev/null

  echo "[*] Added simple /var/www/html/index.html"

fi

# --- Task 7 optional: create labmate user (no password needed for chown demo) ---

if $CREATE_LABMATE; then

  if id labmate >/dev/null 2>&1; then

    echo "[*] User 'labmate' already exists (skipping)."

  else

    echo "[*] Creating user 'labmate' (sudo)..."

    sudo useradd -m -s "$LABMATE_SHELL" labmate || true

    # No password; students don't need to log in for chown/group checks.

  fi

fi

# --- Teacher notes quick-reference ---

cat > "${TEACHER_NOTE}" <<EOF

Ubuntu Scavenger Hunt — Teacher Notes

====================================

Seeded items on: $(date -Iseconds)

User: $(whoami)  Host: $(hostname)

Flags & Seeds:

- Task 1: ~/.whereami.flag  -> ${FLAG1}

  * Activated by a pwd alias injected into ~/.bashrc (reload the terminal).

- Task 2: ~/hunt/level1/.readme  -> ${FLAG2}

- Task 4: ~/${BIRD}_notes/       -> BIRD flag is ${BIRD}

- Task 5: nginx installed & started; students create /var/www/html/clue.txt

- Task 7: user 'labmate' created (no password)

Packages installed:

- ${APT_PACKAGES[*]}

Clean-up suggestions:

- Remove pwd alias lines between '# SCAV_HUNT_PWD_ALIAS' and next blank in ~/.bashrc

- rm -f ~/.whereami.flag

- rm -rf ~/hunt ~/${BIRD}_notes

- sudo deluser --remove-home labmate (if desired)

- sudo apt-get remove --purge nginx tree htop lsb-release -y (optional)

EOF

echo "[*] Wrote teacher notes to ${TEACHER_NOTE}"

echo

echo "All set! 👉 Restart or open a new terminal so the pwd alias takes effect."

echo "Quick test commands:"

echo "  pwd            # should print your path + ${FLAG1}"

echo "  cat ~/hunt/level1/.readme"

echo "  tree ~ | head  # should show ${BIRD}_notes"

echo "  curl -I http://127.0.0.1   # nginx running"