added backup script

backup_docker.sh

@@ -0,0 +1,121 @@
+#!/bin/bash
+set -euo pipefail
+
+# === Docker Backup Script ===
+# Creates a compressed backup of a Docker directory (--backup / -b),
+# or deletes backups older than a specified number of days (--clean / -c <days>).
+
+# --- Configuration ---
+DEST="/home/pi/docker_backup"
+SOURCE="/home/pi/docker"
+
+# --- Functions ---
+
+show_help() {
+  cat <<EOF
+Usage: $(basename "$0") [COMMAND]
+
+Commands (choose one):
+  --backup, -b
+        Create a new compressed backup of the directory: ${SOURCE}
+        Example: $(basename "$0") --backup
+
+  --clean, -c <days>
+        Delete backups in ${DEST} older than <days>. <days> must be a positive integer.
+        There is NO default age; this parameter is required when using --clean.
+        Example: $(basename "$0") --clean 14
+
+  --help, -h
+        Show this help message.
+
+Notes:
+- The script must be called with exactly one command (either --backup/-b or --clean/-c <days>).
+- If you provide invalid or missing arguments, the script will exit with an error.
+EOF
+}
+
+is_positive_integer() {
+  [[ "$1" =~ ^[1-9][0-9]*$ ]]
+}
+
+create_backup() {
+  local current_date file_path
+  current_date=$(date +"%Y%m%d_%H%M%S")
+  file_path="${DEST}/${current_date}_docker.tar.gz"
+
+  echo
+  echo "Starting Docker backup at: ${current_date}"
+  echo "Source: ${SOURCE}"
+  echo "Destination: ${file_path}"
+  echo
+
+  mkdir -p "$DEST"
+  tar -cpzf "$file_path" "$SOURCE" --checkpoint=.1000
+  echo
+  echo "Backup created: ${file_path}"
+  echo
+  echo "Contents of backup directory:"
+  ls -lah "$DEST"
+}
+
+clean_backups() {
+  local days="$1"
+
+  if ! is_positive_integer "$days"; then
+    echo "Error: <days> must be a positive integer. Got: '$days'"
+    exit 1
+  fi
+
+  if [[ ! -d "$DEST" ]]; then
+    echo "Error: backup directory does not exist: $DEST"
+    exit 1
+  fi
+
+  echo
+  echo "Deleting backups in '${DEST}' older than ${days} days..."
+  echo
+
+  find "$DEST" -type f -name "*.tar.gz" -mtime +"$days" -print -delete
+
+  echo
+  echo "Deletion complete."
+  echo
+  echo "Remaining backups:"
+  ls -lah "$DEST" || true
+}
+
+# --- Main Argument Handling ---
+
+if [[ $# -eq 0 ]]; then
+  echo "Error: no parameters provided."
+  echo "Use --help or -h to see available options."
+  exit 1
+fi
+
+case "$1" in
+  --help|-h)
+    show_help
+    exit 0
+    ;;
+  --backup|-b)
+    if [[ $# -ne 1 ]]; then
+      echo "Error: --backup / -b takes no additional arguments."
+      echo "Use --help or -h to see usage."
+      exit 1
+    fi
+    create_backup
+    ;;
+  --clean|-c)
+    if [[ $# -ne 2 ]]; then
+      echo "Error: --clean / -c requires a single <days> argument (no default)."
+      echo "Example: $(basename "$0") --clean 30"
+      exit 1
+    fi
+    clean_backups "$2"
+    ;;
+  *)
+    echo "Error: unknown parameter: $1"
+    echo "Use --help or -h to see available options."
+    exit 1
+    ;;
+esac