In an admin ui, you list the names of secrets only, and provide a “reveal” or a “replace” on each one. They are never decrypted unless explicitly asked for.
Is this perfect? Absolutely not. The key is controlled by the company, but it can be derived in a manner that doesn’t allow for the dump of everything if it’s leaked.
I still like the approach, but I'm afraid that it feels more secure than it is, and people should be aware of that.
But honestly, if you’re in the container, and the application running in the container can get secrets, so can a shell user.
_Maybe_ there’s a model where the platform exposes a Unix domain socket and checks the PID, user, group of the connection, and delivers secrets that way? This has its problems, too, like it being non-standard, only possible in some scenarios and otherwise fallible… but better than nothing? If you reap the container when that process dies, you can’t race for the same PID, at least. I dunno