[RFC] File-based secrets

[Kapil Arya <ka...@mesosphere.io>]

Hi All,

Recently, we started working on providing file-based secrets for Mesos
tasks (MESOS-7418 <https://issues.apache.org/jira/browse/MESOS-7418>). The
goal is to allow users to populate files within a task's environment with
contents fetched from a backend secret store. A new secret fetching module
interface is proposed to allow interaction with arbitrary third-party
secret stores.

Further details are covered in the following design doc:

https://docs.google.com/document/d/18raiiUfxTh-JBvjd6RyHe_TOScY87G_bMi5zBzMZmpc/

There might be a few minor pieces missing, but most of the design is there
and should answer most concerns. Please do raise an issue if you find
something missing. As always, any feedback is most welcome.

Best,
Kapil