rp5: move things in separate configs, to be reused

modules/nixos/services/openssh/default.nix

@@ -0,0 +1,29 @@
+{
+  lib,
+  config,
+  namespace,
+  ...
+}:
+let
+  cfg = config.${namespace}.services.openssh;
+  inherit (lib) mkIf mkEnableOption;
+in
+{
+  options.${namespace}.services.openssh = {
+    enable = mkEnableOption "Enable SSH";
+  };
+
+  config = mkIf cfg.enable {
+    services.openssh = {
+      enable = true;
+      settings = {
+        PasswordAuthentication = false;
+        KbdInteractiveAuthentication = false;
+      };
+    };
+
+    services.fail2ban = {
+      enable = true;
+    };
+  };
+}