#!/usr/bin/sh
if [[ $# -eq 0 ]]; then
	echo "Usage: $0 <backup_dir>"
	exit
fi

destination=$1
if ! type "pv" > /dev/null; then
	echo 'pv' command not found on your system, install it to get a nice progress indicator...
else
       PV=" pv "	
fi

docker images | awk '{ 
if ($1 != "REPOSITORY") 
	{ 
		original = $1;
		size = $5;
		gsub("/","_",$1);
		normalised_container_name = $1
		print "Container: $original => $destination/normalised_container_name.tgz";
		system("docker save $original | $PV | gzip -c > $destination/$normalised_container_name.tgz")

	};
}' 

for container in $containers
do
	normalised_container_name=${container//\//_}
	echo "Container: $container => $1/$normalised_container_name.tgz"
	if [[ -s $1/$normalised_container_name.tgz ]]; then
		echo "File $1/$normalised_container_name already exists with filesize > 0, skipping backup..."
		continue
	fi
	
done