Runtime cache ------------- The ``runtime-cache`` directory caches information used by subuser while prepairing subusers to be run. The directory contains a set of subdirectories each named with the Docker image Id of a given installed-image. Each image directory contains a set of JSON files named with the SHA512 hash of the ``permissions.json`` file that was used to generate the runtime and postfixed with ``.json``. In summary, the path to a given runtime config might look like ``$HOME/.subuser/runtime-cache//.json``. Each permissions-specific JSON file caches information needed to run a specific installed subuser image with a specific set of permissions. Each permissions specific JSON file is a valid JSON file containing a single JSON object with the following properites: * ``run-ready-image-id`` - the Docker image Id of the image which was prepaired for running that subuser. .