start set up for multi-location nixos flake

nixos/hosts/olympus/vault/configuration.nix

@@ -0,0 +1,35 @@
+# Edit this configuration file to define what should be installed on
+# your system.  Help is available in the configuration.nix(5) man page
+# and in the NixOS manual (accessible by running ‘nixos-help’).
+
+{ config, pkgs, ... }:
+let port = 8200;
+in {
+  networking.hostName = "vault";
+
+  # This value determines the NixOS release from which the default
+  # settings for stateful data, like file locations and database versions
+  # on your system were taken. It‘s perfectly fine and recommended to leave
+  # this value at the release version of the first install of this system.
+  # Before changing this value read the documentation for this option
+  # (e.g. man configuration.nix or on https://nixos.org/nixos/options.html).
+  system.stateVersion = "21.05"; # Did you read the comment?
+
+  # Additional packages
+  environment.systemPackages = with pkgs; [ ];
+
+  # Vault
+  networking.firewall.allowedTCPPorts = [ port ];
+
+  services.vault = {
+    enable = true;
+    # bin version includes the UI
+    package = pkgs.vault-bin;
+    address = "0.0.0.0:${toString port}";
+    storageBackend = "file";
+    storagePath = "/var/lib/vault";
+    extraConfig = ''
+      ui = true
+    '';
+  };
+}