How to use Docker volumes with an R example

docker_volumes.sh

#!/bin/bash
# M Y 2018-08-21. An example script on Docker volumes showing
# how to run a sandboxed 'R' code inside the container.
# Tip: Using `ls` (or else) with the volumes is helpful especially
# when need to understand why some particular files cannot be found.

set -x

V="rvol"
mkdir $V

printf "2 * 4 \n\ncat('success!!') \n\n " > $V/calc.R

## With VOL layer in the Dockerfile:
printf "FROM r-base:latest \n\nVOLUME /%s\n " "$V)"  > Dockerfile

docker build -t test-docker-vol .

docker run --rm \
        -v $PWD/$V:/$V \
        test-docker-vol \
        Rscript $V/calc.R

## With binding volume arg command:
docker run --rm \
        -v $PWD/$V:/$V r-base:latest \
        Rscript rvol/calc.R

## Clean up:
rm Dockerfile
rm -r $V/*
rmdir $V

docker rmi test-docker-vol