Create a copy of a Docker volume

docker-volume-copy

#!/bin/sh

src="$1"
dest="$2"

if test "$src" = ""
then
    echo "Usage: $0 <source-volume> [new-volume]" >&2
    exit 1
fi

if ! docker volume inspect -- "$src" >/dev/null 2>&1
then
    echo "Error: Cannot inspect source volume: $src" >&2
    echo "Verify that the volume exists and you can access the Docker daemon." >&2
    exit 2
fi

if test "$dest" != "" && docker volume inspect -- "$dest" >/dev/null 2>&1
then
    echo "Error: Destination volume already exists: $dest" >&2
    exit 3
fi

if ! dest="$(docker volume create -- "$dest")"
then
    echo "Failed to create destination volume" >&2
    exit 4
fi

echo "Copying data from source volume to destination volume" >&2
if ! docker run --rm -it -v "$src:/from:ro" -v "$dest:/to:rw" alpine ash -c "cd /from; cp -av . /to"
then
   echo "Failed to copy data"
   exit 5
fi

printf "%s\n" "$dest"