Restore a single volume from a tar archive to a container

volume_restore.sh

#!/bin/bash
# Restore a single volume from a tar archive to a Docker container
NEW_CONTAINER_NAME=$1
BACKUPTAR=$2

usage() {
  echo "Usage: $0 [container name] ([backup.tar])"
  exit 1
}

if [ -z $BACKUPTAR ]
then
  BACKUPTAR="backup.tar"
fi

TARDIR=$(dirname "${BACKUPTAR}")
TARFN=$(basename "${BACKUPTAR}")

if [[ $TARDIR != /* ]]
then
  TARDIR="$(pwd)/$TARDIR"
fi

if [ -z $NEW_CONTAINER_NAME ]
then
  echo "Error: missing container name parameter."
  usage
fi

docker run --rm --volumes-from $NEW_CONTAINER_NAME -v $TARDIR:/backup busybox tar xvf /backup/$TARFN