Virtualisation

• tweag on VM's - has all the commands you could ever want.
• nixpkgs/nixos/lib - got some fun stuff.

Using this stuff to try out xmonad. Haskell configuration seems really promising, and WM seem like a perfect candidate for VM testing.

To build a VM from ./config.nix run:

nix-build '<nixpkgs/nixos>' -A vm -I nixos-config=./config.nix

This builds vm attrib from nixos subdir of nixpkgs with nixos-config path swapped for ./config.nix. Nixpkgs is pretty complicated so I haven't traced where this attribute is defined, but hope to soon.

This file seems to be what's evaluated through the command above.

The VM is pretty slow, which I hope to look into fixing once I find actuall documentation on the issue. Same goes for network access, it doesn't seem to be accessible from the host by default.

On speed - that's seems to be a QEMU issue, so might read this. On network - read the source.

Apart from that, you can run subservices with this thing, but that doesn't seem practical. I hope to use it for testing configurations once the stuff above is figured out. Ideally it should be possible to

deploy a whole cluster of virtual machines and see how they interract with something like wireshark.

It's possible to run integration tests with VM's, but I don't know the exact mechanics of this process. This seems to be what I actually want.