How to define a variable in a Dockerfile?

Question

In my Dockerfile, I would like to define variables that I can use later in the Dockerfile.

I am aware of the

Answer 1

To answer your question:

In my Dockerfile, I would like to define variables that I can use later in the Dockerfile.

You can define a variable with:

ARG myvalue=3

Spaces around the equal character are not allowed.

And use it later with:

RUN echo $myvalue > /test