buildkit: init at v0.4.0

compile `builtkitd` only on Linux, `buildkitctl` on all envs.

Signed-off-by: Vincent Demeester <[e-mail]>

pkgs/development/tools/buildkit/default.nix

···
+{ stdenv, fetchFromGitHub, buildGoPackage }:
+
+buildGoPackage rec {
+  pname = "buildkit";
+  version = "0.4.0";
+  rev = "v${version}";
+
+  goPackagePath = "github.com/moby/buildkit";
+  subPackages = [ "cmd/buildctl" ] ++ stdenv.lib.optionals stdenv.isLinux [ "cmd/buildkitd" ];
+
+  src = fetchFromGitHub {
+    inherit rev;
+    owner = "moby";
+    repo = "buildkit";
+    sha256 = "0gkwcjqbcskn63y79jwa26hxkps452z4bgz8lrryaskzbdpvhh3d";
+  };
+
+  meta = with stdenv.lib; {
+    description = "Concurrent, cache-efficient, and Dockerfile-agnostic builder toolkit";
+    homepage = https://github.com/moby/buildkit;
+    license = licenses.asl20;
+    maintainers = with maintainers; [ vdemeester ];
+  };
+}

pkgs/top-level/all-packages.nix

···
 
   buildah = callPackage ../development/tools/buildah { };
 
+  buildkit = callPackage ../development/tools/buildkit { };
+
   bukubrow = callPackage ../tools/networking/bukubrow { };
 
   burpsuite = callPackage ../tools/networking/burpsuite {};