podman/docs/source/markdown/options/file.md

####> This option file is used in: ####> podman build, farm build ####> If file is edited, make sure the changes ####> are applicable to all of those.

--file, -f=Containerfile

Specifies a Containerfile which contains instructions for building the image, either a local file or an http or https URL. If more than one Containerfile is specified, FROM instructions are only be accepted from the last specified file.

If a build context is not specified, and at least one Containerfile is a local file, the directory in which it resides is used as the build context.

Specifying the option -f - causes the Containerfile contents to be read from stdin.