#!/bin/bash
# Just backups volumes of running containers
# If rsync stucks consider:
# @see https://stackoverflow.com/questions/20773118/rsync-suddenly-hanging-indefinitely-during-transfers
#
backup_time="$(date '+%Y%m%d%H%M%S')";
backups_folder="/Backups/";
repository_name="$(cd "$(dirname "$(readlink -f "${0}")")" && basename `git rev-parse --show-toplevel`)";
machine_id="$(sha256sum /etc/machine-id | head -c 64)";
backup_repository_folder="$backups_folder$machine_id/$repository_name/";
for volume_name in $(docker volume ls --format '{{.Name}}');
do
  echo "start backup routine: $volume_name";
  containers="$(docker ps --filter volume="$volume_name" --format '{{.Names}}')";
  containers_array=($containers)
  container=${containers_array[0]}
  echo "stop containers:" && docker stop $containers
  for source_path in $(docker inspect --format "{{ range .Mounts }}{{ if eq .Type \"volume\"}}{{ if eq .Name \"$volume_name\"}}{{ println .Destination }}{{ end }}{{ end }}{{ end }}" "$container");
  do
    destination_path="$backup_repository_folder""latest/$volume_name";
    raw_destination_path="$destination_path/raw"
    prepared_destination_path="$destination_path/prepared"
    log_path="$backup_repository_folder""log.txt";
    backup_dir_path="$backup_repository_folder""diffs/$backup_time/$volume_name";
    raw_backup_dir_path="$backup_dir_path/raw";
    prepared_backup_dir_path="$backup_dir_path/prepared";
    if [ -d "$destination_path" ]
      then
        echo "backup volume: $volume_name";
      else
        echo "first backup volume: $volume_name"
        mkdir -vp "$raw_destination_path";
        mkdir -vp "$raw_backup_dir_path";
        mkdir -vp "$prepared_destination_path";
        mkdir -vp "$prepared_backup_dir_path";
    fi
    docker run --rm --volumes-from "$container" -v "$backups_folder:$backups_folder" "kevinveenbirkenbach/alpine-rsync" sh -c "
    rsync -abP --delete --delete-excluded --log-file=$log_path --backup-dir=$raw_backup_dir_path '$source_path/' $raw_destination_path";
    echo "start containers:" && docker start $containers;
  done
  echo "end backup routine: $volume_name";
done