use a custom NixOS option instead of relying on hostname to determine inclusion of rootless container services

nixos-configuration/configuration.nix

@@ -8,6 +8,7 @@
 {
   imports = [
     ./bootloader-configuration.nix
+    ./custom-options.nix
     ./misc-configuration.nix
     ./network-configuration.nix
     ./packages/system-packages.nix

nixos-configuration/custom-options.nix

@@ -0,0 +1,13 @@
+{ lib, ... } :
+
+{
+  options = {
+    custom-options = {
+      enableRootlessContainers = lib.mkOption {
+        description = "Enable all systemd services that start rootless (Podman) containers for the home-manager user";
+        type = lib.types.bool;
+        default = false;
+      };
+    };
+  };
+}

nixos-configuration/home-manager/nixos-home.nix

@@ -78,7 +78,7 @@ in
     imports = [
       ./common-home.nix
       ./virt-ovmf.nix
-    ] ++ (lib.optionals (osConfig.networking.hostName == "reddish") [
+    ] ++ (lib.optionals osConfig.custom-options.enableRootlessContainers [
       # TODO: self-host flakestry.dev so that I don't go over the piddly rate-limit of GitHub
       ../systemd-services/podman/podman-init.nix
       ../systemd-services/podman/container-caddy-vishwambhar.nix

nixos-configuration/hosts/reddish/default.nix

@@ -26,6 +26,7 @@
     fsType = "xfs";
   };
 
+  custom-options.enableRootlessContainers = true;
   networking.firewall.allowedTCPPorts = [
     8001 # caddy HTTP
     8002 # caddy HTTPS