parted /dev/vda mklabel msdos
parted /dev/vda mkpart primary ext4 0% 100%
mkfs.ext4 -L system /dev/vda1
mount /dev/vda1 /mnt/

nix-env -iA nixos.gitMinimal
git clone https://code.dumpstack.io/infra/code.dumpstack.io.git /mnt/etc/nixos/

nix-channel --add https://nixos.org/channels/nixos-unstable nixos
nix-channel --update

cd /mnt/etc/nixos
cp var.example.nix var.nix
vim var.nix

nixos-generate-config --root /mnt

nixos-install
reboot

After install

nix-channel --add https://nixos.org/channels/nixos-unstable nixos
nix-channel --update