!/bin/bash

#Author: Guido Diepen

#Convenience script that can help me to easily create a gzip of a given
#data volume. The script is mainly useful if you are using named volumes


#First check if the user provided all needed arguments
if [ "$1" = "" ]
then
        echo "Please provide a source volume name"
        exit
fi

if [ "$2" = "" ]
then
        echo "Please provide a destination volume name"
        exit
fi


#Check if the source volume name does exist
docker volume inspect $1 > /dev/null 2>&1
if [ "$?" != "0" ]
then
        echo "The source volume \"$1\" does not exist"
        exit
fi

#Now check if the destination exists
if [ ! -d "$2" ]
then
        echo "The destination \"$2\" doesn't exist"
        exit
fi

echo "Copying data from source volume \"$1\" to destination volume \"$2\"..."
docker run --rm \
           -i \
           -t \
           -v $1:/from \
           -v $2:/to \
           alpine ash -c "cd /from ; tar zcvf \"/to/$1`date +%Y%m%d%H%M`.gz\" ."