i have ran into problems in the past attempting to mount a file that is accidentally not present.

docker will assume that i want to mount a folder and it will create a folder (named after the missing file) creating confusion.

for example:

docker run -v /path/to/file.txt:/file.txt me/my-image

will create a folder named file.txt at /path/to if /path/to/file.txt doesn't exist.

i burned a few hours on this once with a docker-ized node app that was complaining that i was trying to open a folder as a file.

i thought it might be smoother if i could signal to docker that i am going after a file v a folder, and then if i specify :ro have it throw an error if it doesn't exist, or if it is :rw (default) have it just create the file.

so something like a -f option to indicate mounting a file, like so:

docker run -f /path/to/file.txt:/file.txt me/my-image