Interactive Dockerfile testing

docker-build-interactive

# Run the FROM image interactively with the current directory mounted to /build_dir
# Eg, for python:3.8-alpine...
docker run -it -v /path/to/build_dir:/build_dir --entrypoint=/bin/sh python:3.8-alpine

# Once inside the container interactively, set up some functions that enable the shell to 'run' the Dockerfile
FROM() {
echo FROM $*
}

ENV() {
export $1=$2
}

RUN() {
$*
}

COPY() {
cp -a /build_dir/$1 $2
}

# Now, you can simply copy/paste the contents of the Dockerfile and they should run. You can build on this of course, this is just a quick gist to get you started