diff --git a/default.nix b/default.nix
index f337a6a..d4d964a 100644
--- a/default.nix
+++ b/default.nix
@@ -1,14 +1,21 @@
 { pkgs ? import <nixpkgs> {}, lib ? pkgs.lib }:
 
-let
-  lib' = lib.extend (lib: self: import ./lib.nix { inherit lib pkgs; });
+with lib;
 
-  specialArgs' = {
+let
+  kubenixLib = import ./lib { inherit lib pkgs; };
+  lib' = lib.extend (lib: self: import ./lib/extra.nix { inherit lib pkgs; });
+
+  defaultSpecialArgs = {
     inherit kubenix;
   };
 
-  evalKubernetesModules = {module ? null, modules ? [module], specialArgs ? specialArgs', ...}@attrs: let
-    attrs' = lib.filterAttrs (n: _: n != "module") attrs;
+  evalModules = {
+    module ? null,
+    modules ? [module],
+    specialArgs ? defaultSpecialArgs, ...
+  }@attrs: let
+    attrs' = filterAttrs (n: _: n != "module") attrs;
   in lib'.evalModules (attrs' // {
     inherit specialArgs modules;
     args = {
@@ -17,14 +24,11 @@ let
     };
   });
 
-  buildResources = args:
-    (evalKubernetesModules args).config.kubernetes.generated;
-
   modules = import ./modules;
 
   kubenix = {
-    inherit evalKubernetesModules buildResources kubenix;
+    inherit evalModules kubenix;
 
-    lib = lib';
+    lib = kubenixLib;
   } // modules;
 in kubenix
diff --git a/lib/default.nix b/lib/default.nix
new file mode 100644
index 0000000..266b6ed
--- /dev/null
+++ b/lib/default.nix
@@ -0,0 +1,6 @@
+{ lib, pkgs }:
+
+(import ./extra.nix { inherit pkgs lib; }) // {
+  k8s = import ./k8s.nix { inherit lib; };
+  docker = import ./docker.nix { inherit lib pkgs; };
+}
diff --git a/lib/docker.nix b/lib/docker.nix
new file mode 100644
index 0000000..8e7451f
--- /dev/null
+++ b/lib/docker.nix
@@ -0,0 +1,15 @@
+{ lib, pkgs }:
+
+with lib;
+
+{
+  copyDockerImages = { images,  dest, args ? "" }:
+    pkgs.writeScriptBin "copy-docker-images" (concatMapStrings (image: ''
+      #!${pkgs.bash}/bin/bash
+
+      set -e
+
+      echo "copying ${image.imageName}:${image.imageTag}"
+      ${pkgs.skopeo}/bin/skopeo copy ${args} $@ docker-archive:${image} ${dest}/${image.imageName}:${image.imageTag}
+    '') images);
+}
diff --git a/lib.nix b/lib/extra.nix
similarity index 83%
rename from lib.nix
rename to lib/extra.nix
index e1f832f..a165d41 100644
--- a/lib.nix
+++ b/lib/extra.nix
@@ -1,9 +1,8 @@
-{lib, pkgs}:
+{ lib, pkgs }:
 
 with lib;
 
-let
-in rec {
+rec {
   moduleToAttrs = value:
     if isAttrs value
     then mapAttrs (n: v: moduleToAttrs v) (filterAttrs (n: v: !(hasPrefix "_" n) && v != null) value)
@@ -39,9 +38,8 @@ in rec {
 
   exp = base: exp: foldr (value: acc: acc * base) 1 (range 1 exp);
 
-  octalToDecimal = value:
-    (foldr (char: acc: {
-      i = acc.i + 1;
-      value = acc.value + (toInt char) * (exp 8 acc.i);
-    }) {i = 0; value = 0;} (stringToCharacters value)).value;
+  octalToDecimal = value: (foldr (char: acc: {
+    i = acc.i + 1;
+    value = acc.value + (toInt char) * (exp 8 acc.i);
+  }) {i = 0; value = 0;} (stringToCharacters value)).value;
 }
diff --git a/lib/k8s.nix b/lib/k8s.nix
new file mode 100644
index 0000000..da7729c
--- /dev/null
+++ b/lib/k8s.nix
@@ -0,0 +1,54 @@
+{ lib }:
+
+with lib;
+
+rec {
+  mkSecretOption = {description ? "", default ? null}: mkOption {
+    inherit description;
+    type = types.nullOr (types.submodule {
+      options = {
+        name = mkOption {
+          description = "Name of the secret where secret is stored";
+          type = types.str;
+        };
+
+        key = mkOption {
+          description = "Name of the key where secret is stored";
+          type = types.str;
+        };
+      };
+
+      config = mkDefault (if default == null then {} else default);
+    });
+    default = {};
+  };
+
+  secretToEnv = value: {
+    valueFrom.secretKeyRef = {
+      inherit (value) name key;
+    };
+  };
+
+  # Creates kubernetes list from a list of kubernetes objects
+  mkList = { items, labels ? {} }: {
+    kind = "List";
+    apiVersion = "v1";
+
+    inherit items labels;
+  };
+
+  # Creates hashed kubernetes list from a list of kubernetes objects
+  mkHashedList = { items, labels ? {} }: let
+    hash = builtins.hashString "sha1" (builtins.toJSON items);
+
+    labeledItems = map (item: recursiveUpdate item {
+      metadata.labels."kubenix/hash" = hash;
+    }) items;
+
+  in mkList {
+    items = labeledItems;
+    labels = {
+      "kubenix/hash" = hash;
+    } // labels;
+  };
+}
diff --git a/modules/k8s/default.nix b/modules/k8s/default.nix
index 340d7b9..49a0070 100644
--- a/modules/k8s/default.nix
+++ b/modules/k8s/default.nix
@@ -1,4 +1,4 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, pkgs, k8s, ... }:
 
 with lib;
 
@@ -32,12 +32,6 @@ let
     ) resources
   );
 
-  toKubernetesList = resources: {
-    kind = "List";
-    apiVersion = "v1";
-    items = resources;
-  };
-
   apiOptions = { config, ... }: {
     options = {
       definitions = mkOption {
@@ -114,7 +108,8 @@ let
   indexOf = lst: value:
     head (filter (v: v != -1) (imap0 (i: v: if v == value then i else -1) lst));
 in {
-  imports = [./lib.nix];
+  # expose k8s helper methods through arg in modules
+  config._module.args.k8s = import ../../lib/k8s.nix { inherit lib; };
 
   options.kubernetes.version = mkOption {
     description = "Kubernetes version to use";
@@ -222,7 +217,7 @@ in {
   }) cfg.customResources;
 
   options.kubernetes.objects = mkOption {
-    description = "Attribute set of kubernetes objects";
+    description = "List of generated kubernetes objects";
     type = types.listOf types.attrs;
     apply = items: sort (r1: r2:
       if elem r1.kind cfg.resourceOrder && elem r2.kind cfg.resourceOrder
@@ -239,25 +234,11 @@ in {
   ) cfg.api.resources);
 
   options.kubernetes.generated = mkOption {
+    description = "Generated kubernetes list object";
     type = types.attrs;
-    description = "Generated json file";
   };
 
-  config.kubernetes.generated = let
-    kubernetesList = toKubernetesList cfg.objects;
-
-    hashedList = kubernetesList // {
-      labels."kubenix/build" = cfg.hash;
-      items = map (resource: recursiveUpdate resource {
-        metadata.labels."kubenix/build" = cfg.hash;
-      }) kubernetesList.items;
-    };
-  in hashedList;
-
-  options.kubernetes.hash = mkOption {
-    type = types.str;
-    description = "Output hash";
+  config.kubernetes.generated = k8s.mkHashedList {
+    items = config.kubernetes.objects;
   };
-
-  config.kubernetes.hash = builtins.hashString "sha1" (builtins.toJSON cfg.objects);
 }
diff --git a/modules/k8s/lib.nix b/modules/k8s/lib.nix
deleted file mode 100644
index be78877..0000000
--- a/modules/k8s/lib.nix
+++ /dev/null
@@ -1,35 +0,0 @@
-{ lib, ... }:
-
-with lib;
-
-let
-  k8s = {
-    mkSecretOption = {description ? "", default ? null}: mkOption {
-      inherit description;
-      type = types.nullOr (types.submodule {
-        options = {
-          name = mkOption {
-            description = "Name of the secret where secret is stored";
-            type = types.str;
-          };
-
-          key = mkOption {
-            description = "Name of the key where secret is stored";
-            type = types.str;
-          };
-        };
-
-        config = mkDefault (if default == null then {} else default);
-      });
-      default = {};
-    };
-
-    secretToEnv = value: {
-      valueFrom.secretKeyRef = {
-        inherit (value) name key;
-      };
-    };
-  };
-in {
-  _module.args.k8s = k8s;
-}
diff --git a/modules/testing/default.nix b/modules/testing/default.nix
index 80eafcc..6027149 100644
--- a/modules/testing/default.nix
+++ b/modules/testing/default.nix
@@ -71,7 +71,7 @@ let
     nixosTesting.makeTest {
       inherit name;
 
-      nodes.kube = { config, pkgs, lib, nodes, ... }: {
+      nodes.kube = { config, pkgs, nodes, ... }: {
         imports = [ kubernetesBaseConfig ];
         services.kubernetes = {
           roles = ["master" "node"];
@@ -113,14 +113,14 @@ let
       config._module.args.test = config;
     }] ++ cfg.defaults;
 
-    test = (kubenix.evalKubernetesModules {
+    test = (kubenix.evalModules {
       check = false;
       inherit modules;
     }).config.test;
 
     evaled =
       if test.enable
-      then builtins.trace "testing ${test.name}" (kubenix.evalKubernetesModules {
+      then builtins.trace "testing ${test.name}" (kubenix.evalModules {
         inherit modules;
       })
       else {success = false;};
diff --git a/tests/default.nix b/tests/default.nix
index f32926f..70c6cd8 100644
--- a/tests/default.nix
+++ b/tests/default.nix
@@ -1,6 +1,6 @@
 { pkgs ? import <nixpkgs> {}
-, kubenix ? import ../. {inherit pkgs;}
-, lib ? kubenix.lib
+, lib ? pkgs.lib
+, kubenix ? import ../. { inherit pkgs lib; }
 , k8sVersions ? ["1.7" "1.8" "1.9" "1.10" "1.11" "1.12" "1.13"]
 
 # whether any testing error should throw an error
@@ -14,7 +14,7 @@ let
 
   tests = listToAttrs (map (version: let
     version' = replaceStrings ["."] ["_"] version;
-  in nameValuePair "v${version'}" (evalModules {
+  in nameValuePair "v${version'}" (kubenix.evalModules {
     modules = [
       kubenix.testing
 
diff --git a/tests/helm/simple.nix b/tests/helm/simple.nix
index 7070b0e..139c2a7 100644
--- a/tests/helm/simple.nix
+++ b/tests/helm/simple.nix
@@ -1,7 +1,7 @@
-{ config, lib, test, pkgs, kubenix, k8s, helm, ... }:
+{ config, lib, test, pkgs, kubenix, helm, ... }:
 
 with lib;
-with k8s;
+with kubenix.lib;
 with pkgs.dockerTools;
 
 let
@@ -56,7 +56,7 @@ in {
       $kube->waitUntilSucceeds("docker load < ${postgresql}");
       $kube->waitUntilSucceeds("docker load < ${postgresqlExporter}");
       $kube->waitUntilSucceeds("docker load < ${minideb}");
-      $kube->waitUntilSucceeds("kubectl apply -f ${toYAML config.kubernetes.generated}");
+      $kube->waitUntilSucceeds("kubectl apply -f ${toYAML config.kubernetes.objects}");
       $kube->waitUntilSucceeds("PGPASSWORD=postgres ${pkgs.postgresql}/bin/psql -h app-psql-postgresql.test.svc.cluster.local -U postgres -l");
     '';
   };