Check for dependencies.

tools/dependency_check.sh

@@ -0,0 +1,42 @@
+#!/bin/bash
+
+set -eu
+
+# List of entries: "executable[:package]"
+entries=(
+  "podman"
+  "podman-compose"
+  "dig:bind9-dnsutils"
+
+)
+
+missing_packages=()
+
+echo "Checking required executables..."
+
+for entry in "${entries[@]}"; do
+  IFS=":" read -r cmd pkg <<< "$entry"
+
+  # If pkg is empty (no colon found), default package name to executable name
+  if [ -z "$pkg" ]; then
+    pkg="$cmd"
+  fi
+
+  if [ -x "$(command -v "$cmd")" ]; then
+    echo "[FOUND] Executable '$cmd' found."
+  else
+    echo "[MISSING] Executable '$cmd' NOT found."
+    missing_packages+=("$pkg")
+  fi
+done
+
+echo
+
+if [ ${#missing_packages[@]} -eq 0 ]; then
+  echo "All executables found."
+else
+  echo >&2 "Missing ${#missing_packages[@]} executables."
+  echo >&2 "Suggested command to install missing packages:"
+  echo >&2 "sudo apt install --no-install-recommends ${missing_packages[*]}"
+  exit 1
+fi