[Nix-dev] Declaring filesystems using functions

[Oliver Matthews]

So,

I have a bunch of containers that I want to bind mount specific directories into. For ease, I intend to mount them at the same point on the parent FS.

a mapped function struck me as the most obvious, but I can't quite get it to work - I have a sort of solution, but there is a layer of indirection which is beating me.

This works:

let bindFS = { container, dir }: 
{ "/var/lib/containers/${container}/${dir}" = { device = "${dir}"; options = "${bind}"; }; };
in
{
  fileSystems =
  bindFS { container="containerName"; dir="somedir1"; } //
  bindFS { container="containerName"; dir="somedir2"; };
}

I tried fileSystems = map bindFS [ { container=... But that fails as it creates anonymous items within fileSystems.

Can someone help with what I've missed?

Regards,
Oliver