#!/usr/bin/env bash
# vim: set tabstop=2 softtabstop=2 shiftwidth=2 expandtab:
#
# Script Name: backup_incus_volumes.sh
# Description: This script backs up all Incus storage volumes
#              listed in the 'default' storage pool to a specified
#              backup directory. It is designed to be invoked by
#              Borgmatic hooks.
# Author: Benoit <forgejo@benoit.jp.net>
# Website: benoit.jp.net
# License: MIT
#
# Dependencies: incus
# Written with the help of ChatGPT
#

# Strict mode
set -euo pipefail

# Set the backup directory
BACKUP_DIR="/var/backups/incus"

# Create the backup directory if it doesn't exist
mkdir -p "$BACKUP_DIR"

# Get the list of volumes and check for errors
volumes=$(incus storage volume list default -f csv -c t,n,u 2>/dev/null)
if [ $? -ne 0 ]; then
  echo "Error: Failed to list storage volumes." >&2
  exit 1
fi

# Check if there are any volumes to back up
if [ -z "$volumes" ]; then
  echo "No volumes found to back up."
  exit 0
fi

# Initialize a success flag
all_backups_successful=true

# Loop through each volume and back it up
while IFS=, read -r type name used; do
  # Ignore images, containers, and unused volumes
  if [[ "$type" == "image" || "$type" == "container" \
    || "$type" == "virtual-machine" || "$used" -eq 0 ]]; then

    continue
  fi

  echo "Backing up volume: $name"

  if incus storage volume export default "$name" \
    --compression=none --volume-only \
    "$BACKUP_DIR/${name}.tar" &> /dev/null; then

    echo "Successfully backed up: $name"
  else
    echo "Error backing up volume: $name" >&2
    all_backups_successful=false
  fi
done <<< "$volumes"

# Final message based on backup success
if $all_backups_successful; then
  echo "Backup completed successfully. All volumes have been backed up to $BACKUP_DIR."
else
  echo "Backup completed with errors. Some volumes may not have been backed up."
fi