Docker build passing command-line argumens

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We can defined command-line parameters in the Dockerfile and then allow the user who builds the image to pass in values on the command line of docker build.

examples/arguments/Dockerfile

FROM ubuntu:22.04

ARG TEXT=foo

RUN echo "Hello" > welcome.txt
RUN echo $TEXT >> welcome.txt

docker build -t mydocker --build-arg TEXT=Bar .