create automatic partition installer

modules/system/installer.nix

@@ -0,0 +1,38 @@
+{ pkgs, ... }: {
+
+  # Inspired by https://github.com/cleverca22/nix-tests/blob/master/kexec/justdoit.nix
+  # This will partition and format drives; use at your own risk.
+
+  type = "app";
+
+  program = pkgs.writeShellScriptBin "installer" ''
+    #!${pkgs.stdenv.shell}
+
+    set -e
+
+    DISK=$1
+    FLAKE=$2
+
+    if [ -z "$DISK" ] || [ -z "$FLAKE" ]; then
+        echo "Missing required parameter."
+        echo "Usage: installer -- <disk> <host>"
+        echo "Example: installer -- nvme0n1 desktop"
+        echo "Flake example: nix run github:nmasur/dotfiles#installer -- nvme0n1 desktop"
+        exit 1
+    fi
+
+    parted /dev/''${DISK} -- mklabel gpt
+    parted /dev/''${DISK} -- mkpart primary 512MiB 100%
+    parted /dev/''${DISK} -- mkpart ESP fat32 1MiB 512MiB
+    parted /dev/''${DISK} -- set 3 esp on
+    mkfs.ext4 -L nixos /dev/''${DISK}p1
+    mkfs.fat -F 32 -n boot /dev/''${DISK}p2
+
+    mount /dev/disk/by-label/nixos /mnt
+    mkdir --parents /mnt/boot
+    mount /dev/disk/by-label/boot /mnt/boot
+
+    nixos-install --flake github:nmasur/dotfiles#''${FLAKE}
+  '';
+
+}