added readme and updated auto-install.sh script to dynamically derive hostnames from flake

installer.nix

@@ -12,7 +12,7 @@
   services.openssh.settings.PermitRootLogin = "yes";
 
   environment.systemPackages = with pkgs; [
-    git curl parted e2fsprogs btrfs-progs util-linux
+    git curl jq parted e2fsprogs btrfs-progs util-linux
   ];
 
 #  environment.etc."flake-url".text = "git+https://gitea.lan.ddnsgeek.com/beatzaplenty/nixos.git?ref=main#nixos";   
@@ -38,8 +38,18 @@ environment.etc."git-credentials".text =
 
 export FLAKE_BASE_URL="git+https://gitea.lan.ddnsgeek.com/beatzaplenty/nixos.git"
 
-# Menu options
-options=("nixos" "docker" "server" "nix-cache" "nix-minimal")
+echo "Fetching available NixOS hosts from flake..."
+mapfile -t options < <(
+  nix eval --json --no-use-registries --no-accept-flake-config \
+    "''${FLAKE_BASE_URL}#nixosConfigurations" \
+    --apply builtins.attrNames \
+  | jq -r '.[]'
+)
+
+if [[ ''${#options[@]} -eq 0 ]]; then
+  echo "ERROR: No NixOS hosts found in ''${FLAKE_BASE_URL}#nixosConfigurations" >&2
+  exit 1
+fi
 
 echo "Choose the flake profile to install:"
 select choice in "''${options[@]}"; do