Work continued on implementing (and fully exploring) void processes. A lot of the groundwork already exists in Jake Hillion's master's thesis.
This week I added a feature that I needed to help build the processes we need for the shell I'm building: mount points with modes!
In addition to the root mount (taken care of with pivot_root), we need to be able to add additional mounts into the process' environment. These can now be added. All mount points can be mounted readonly or readwrite.
Here is the "Hello, World!" example (the /say/hey program has been statically compiled using musl-gcc).
let status =
let void =
empty
|> mount ~mode:R ~src:hey_dir ~tgt:"say"
|> exec [ "/say/hey" ]
in
let t = Void.spawn ~sw void in
Promise.await (Void.exit_status t)
There really is nothing else in there. Without specifying a root mount, the void process is started with an empty tmpfs root. Next on the list is networking!