refactor and simplify

Signed-off-by: Harald Hoyer <harald@hoyer.xyz>

modules/nixos/services/podman/default.nix

@@ -0,0 +1,25 @@
+{ options, config, lib, pkgs, ... }:
+
+with lib;
+with lib.plusultra;
+let cfg = config.plusultra.podman;
+in
+{
+  options.plusultra.podman = with types; {
+    enable = mkBoolOpt false "Whether or not to enable podman.";
+  };
+
+  config = mkIf cfg.enable {
+    virtualisation = {
+      podman = {
+        enable = true;
+
+        # Create a `docker` alias for podman, to use it as a drop-in replacement
+        dockerCompat = true;
+
+        # For Nixos version > 22.11
+        defaultNetwork.settings = { dns_enabled = true; };
+      };
+    };
+  };
+}