Traverse up the directory to find a .doshfile

[lukechilds]

If a .doshfile is found use that as the default image.

Useful for setting system default in ~/.doshfile or committing a .doshfile to your project.

[lukechilds]

The .doshfile could also contain labels to communicate other parameters.

e.g For params to pass to docker run you could add:

LABEL dosh.run_params="--device=/dev/ttyUSB0"

and then if the .doshfile was used it would automatically set up USB access for that container.

[lukechilds]

There should be a warning to the user the first time a .doshfile is used where they are shown the path and asked to confirm they are happy for it to be used. Otherwise a malicious .doshfile could do nasty stuff on the host at build time like upload sensitive data from the host fs to an attacker.