Docker echo environment variable

Question

I\'m trying to write a little docker file that sets a User and just echos the current user as a little example to prove to myself it is working. I\'ve tried a number of variants

Answer 1

Couldn't you set, in the Dockerfile, the ENV command to a default value, and then, when run-ning a container, use the -e, --env dictionary to override what would be interpreted by the:

ENTRYPOINT echo $SOMEENVVAR

form of ENTRYPOINT?