message: docs: note file permissions when using Docker
  Add further info on file permissions to Docker docs. See
  Risk Level: very low
  Testing: n/a
  Docs Changes: yes
  Release Notes: n/a
diff: @@ -179,6 +179,20 @@ You can then configure ``envoy`` to log to files in ``/var/log``
  The default ``envoy`` ``uid`` and ``gid`` are ``101``.
  +The ``envoy`` user also needs to have permission to access any required configuration files mounted
  +into the container.
  +
  +If you are running in an environment with a strict ``umask`` setting, you may need to provide envoy with
  +access either by setting the ``uid`` or ``gid`` of the file, or by making the configuration file readable
  +by the envoy user.
  +
  +One method of doing this without changing any file permissions or running as root inside the container
  +is to start the container with the host user's ``uid``, for example:
  +
  +.. substitution-code-block:: none
  +
  + $ docker run -d --name envoy -e ENVOY_UID=`id -u` -p 9901:9901 -p 10000:10000 envoy:v1
  +
  Sandboxes
  ---------
  