nix(loki): enable podman

nix/hosts/loki/configuration.nix

@@ -15,6 +15,7 @@
     ./modules/authentik.nix
     ./modules/gonic.nix
     ./modules/attic.nix
+    ./modules/podman.nix
 
     ../../modules/base.nix
     ../../modules/dnscrypt.nix

nix/hosts/loki/modules/podman.nix

@@ -0,0 +1,27 @@
+{
+  config,
+  pkgs,
+  ...
+}: {
+  virtualisation = {
+    containers.storage.settings = {
+      # configure for zfs.
+      storage = {
+        driver = "zfs";
+        graphroot = "/var/lib/containers/storage";
+        runroot = "/run/containers/storage";
+      };
+    };
+
+    ## setup podman.
+    podman = {
+      enable = true;
+      dockerCompat = true;
+      defaultNetwork.settings.dns_enable = true;
+    };
+    oci-containers = {
+      ## use podman as the default container engine.
+      backend = "podman";
+    };
+  };
+}