How do I make a comment in a Dockerfile?

Question

I am writing a Dockerfile. Is there a way to make comments in this file?

Does Docker have a comment option that takes the rest of a line and ignores it?

Answer 1

Docker treats lines that begin with # as a comment, unless the line is a valid parser directive. A # marker anywhere else in a line is treated as an argument.

example code:

# this line is a comment

RUN echo 'we are running some # of cool things'

Output:

we are running some # of cool things