I have a long, complicated Dockerfile, and towards the end I do:

ADD . /app
RUN /app/installation.sh

It's frustrating that if I make a modification to the Dockerfile after the ADD (but otherwise don't touch anything in ., the cache is unnecessarily** invalidated. My instinct was to put Dockerfile in .dockerignore but then I hit #7969.

I'm just raising this issue in case there is a possibility of finding a non-intrusive way of fixing or working around this.

(**In my case it's unnecessary because I don't read the Dockerfile from within the container. I don't know whether there are environments we can imagine that might care about the contents of the Dockerfile within the container.)