nvidia-docker: split out nvidia-container-toolkit into separate drv

pkgs/applications/virtualization/nvidia-container-toolkit/default.nix

···
+{ lib
+, fetchFromGitHub
+, buildGoModule
+, callPackage
+, makeWrapper
+, containerRuntimePath
+, configTemplate
+}:
+let
+  nvidia-container-runtime = callPackage ../nvidia-container-runtime {
+    inherit containerRuntimePath configTemplate;
+  };
+in
+buildGoModule rec {
+  pname = "nvidia-container-toolkit";
+  version = "1.3.0";
+  src = fetchFromGitHub {
+    owner = "NVIDIA";
+    repo = pname;
+    rev = "v${version}";
+    sha256 = "04284bhgx4j55vg9ifvbji2bvmfjfy3h1lq7q356ffgw3yr9n0hn";
+  };
+  vendorSha256 = "17zpiyvf22skfcisflsp6pn56y6a793jcx89kw976fq2x5br1bz7";
+  buildFlagsArray = [ "-ldflags=" "-s -w" ];
+  nativeBuildInputs = [ makeWrapper ];
+  postInstall = ''
+    mv $out/bin/{pkg,${pname}}
+    ln -s $out/bin/nvidia-container-{toolkit,runtime-hook}
+
+    wrapProgram $out/bin/nvidia-container-toolkit \
+      --add-flags "-config ${nvidia-container-runtime}/etc/nvidia-container-runtime/config.toml"
+  '';
+
+  meta = with lib; {
+    homepage = "https://github.com/NVIDIA/nvidia-container-toolkit";
+    description = "NVIDIA container runtime hook";
+    license = licenses.bsd3;
+    platforms = platforms.linux;
+    maintainers = with maintainers; [ cpcloud ];
+  };
+}

pkgs/applications/virtualization/nvidia-docker/default.nix

···
 }:
 
 with lib; let
-  nvidia-container-toolkit = buildGoModule rec {
-    pname = "nvidia-container-toolkit";
-    version = "1.3.0";
-    src = fetchFromGitHub {
-      owner = "NVIDIA";
-      repo = "nvidia-container-toolkit";
-      rev = "v${version}";
-      sha256 = "04284bhgx4j55vg9ifvbji2bvmfjfy3h1lq7q356ffgw3yr9n0hn";
-    };
-    vendorSha256 = "17zpiyvf22skfcisflsp6pn56y6a793jcx89kw976fq2x5br1bz7";
-    buildFlagsArray = [ "-ldflags=" "-s -w" ];
-    postInstall = ''
-      mv $out/bin/{pkg,${pname}}
-      cp $out/bin/{${pname},nvidia-container-runtime-hook}
-    '';
-  };
-
 in
 stdenv.mkDerivation rec {
   pname = "nvidia-docker";
···
 
     cp nvidia-docker bin
     substituteInPlace bin/nvidia-docker --subst-var-by VERSION ${version}
-
-    cp ${nvidia-container-toolkit}/bin/nvidia-container-{toolkit,runtime-hook} bin
   '';
 
   installPhase = ''