docker hvernig á að echo v breyta í bash
docker exec <container-name> env
docker RÖK
$ docker build --build-arg some_variable_name=a_value
dockerfile v variabes
FROM busybox
ENV foo /bar
WORKDIR ${foo} # WORKDIR /bar
ADD . $foo # ADD . /bar
COPY \$foo /quux # COPY $foo /quux