FROM – Sets the base image
MAINTAINER – Sets the author field of the generated images
RUN – Execute commands in a new layer on top of the current image and commit the results
CMD – Allowed only once (if many then last one takes effect)
LABEL – Adds metadata to an image
EXPOSE – Informs container runtime port
ENV – Sets an environment variable
ADD – Copy new files, directories
COPY – Copy new files or directories into the filesystem of the container
ENTRYPOINT – Allows you to configure a container that will run as an executable
VOLUME – Creates a mount point and marks it as holding externally mounted volumes from native host or other containers
USER – Sets the username or UID to use when running the image
WORKDIR – Sets the working directory for any RUN, CMD, ENTRYPOINT, COPY, and ADD commands
ARG – Defines a variable that users can pass at build-time to the builder using –build-arg