How to deploy Rails application on client premises(external server)

How can I securely deploy a Rails application to client's on-premises server and prevent viewing and modification of source code.

Client has physical and root access to the server.

can it be done with linux container like docker or any other?
is it possible to create a encrypted linux container that nobody(even root) has access to and requires a username/password to login and access files.

or is it possible to create a compiled executable that doesn’t allow access to the source code?

any other solutions?