Backup multiple docker container volumes to a single borg repository

docker-borg-backup

#!/bin/bash

# Display Help
Help() {
  echo
  echo "docker-borg-backup"
  echo "####################"
  echo
  echo "Description: Backup all docker volumes for specivic containers in a single borg repository."
  echo "The borg repository is assumed to be initialized."
  echo "Syntax: docker-borg-backup [-o|-c|help]"
  echo "Example: docker-borg-backup -c pgadmin_prod,container_2 -o /mnt/backup"
  echo "options:"
  echo "  -o    Borg repository path. Defaults to '/mnt/backup/full-backup'"
  echo "  -c    Docker container(s) name. Seperated by a comma"
  echo "  help  Show docker-volume-backup manual."
  echo
}

# Show help and exit
if [[ $1 == 'help' ]]; then
    Help
    exit
fi

# Process params
while getopts ":c: :o:" opt; do
  case $opt in
    c) containers="$OPTARG"
    ;;
    o) dir="$OPTARG"
    ;;
    \?) echo "Invalid option -$OPTARG" >&2
    Help
    exit;;
  esac
done

# Fallback to environment vars and default values
: ${dir:='/mnt/backup/full-backup'}

# Verify variables
[[ -z "$dir" ]] && { echo "Parameter -o | borg repository path is empty" ; exit 1; }
[[ -z "$containers" ]] && { echo "Parameter -c | containers is empty" ; exit 1; }

# create the container array
IFS=',' read -ra container_array <<< "$containers"

# loop through each container and mount it's volumes
for container in "${container_array[@]}"
do
  echo "stopping container $container"
  docker container stop $container

  vol_list=($(docker inspect -f '{{ range .Mounts }}{{ .Name }} {{ end }}' $container))

  for vol in "${vol_list[@]}"
  do
    data_path=$(docker volume inspect --format '{{.Mountpoint}}' "$vol")
    mnt_path=/mnt/borg/$vol
    echo "mount volume $vol $data_path $mnt_path"
        
    if [ ! -d $mnt_path ] ; then
      sudo mkdir $mnt_path
      sudo mount --bind -o ro $data_path $mnt_path
    fi
  done
done

backup_name=backup-$(date +%Y-%m-%d-%H%-M%S)
printf "backup name: %s\n" "$backup_name"

#  Perform the backup
borg create --stats --compression lz4 --exclude '*.git' $dir::$backup_name /mnt/borg/

# Unmounting the volumes and restarting the containers
for container in "${container_array[@]}"
do
  echo "restarting the container"
  vol_list=($(docker inspect -f '{{ range .Mounts }}{{ .Name }} {{ end }}' $container))

  for vol in "${vol_list[@]}"
  do
    mnt_path=/mnt/borg/$vol
    echo "unmounting & removing $mnt_path for volume $vol"

    sudo umount $mnt_path
    sudo rm $mnt_path -vrf
  done

  echo "Restarting the container: $container"
  docker container start $container
done

# Notify if backup has finished
echo "The Docker volume backup has finished"