Merge pull request #170 from Anderssorby/acs/nix-build

Add nix build

.envrc

+use_nix
+eval "$(lorri direnv)"

.gitignore

@@ -10,4 +10,7 @@
 .cargo
 
 # The cache for chain data in container
-.local
\ No newline at end of file
+.local
+
+# direnv cache
+.direnv

README.md

@@ -9,6 +9,11 @@ A fresh FRAME-based [Substrate](https://www.substrate.io/) node, ready for hacki
 Follow the steps below to get started with the Node Template, or get it up and running right from your browser 
 in just a few clicks using [Playground](https://playground.substrate.dev/) :hammer_and_wrench:
 
+### Using Nix
+
+Install [nix](https://nixos.org/) and optionally [direnv](https://github.com/direnv/direnv) and [lorri](https://github.com/target/lorri) for a fully plug
+and play experience for setting up the development environment. To get all the correct dependencies activate direnv `direnv allow` and lorri `lorri shell`.
+
 ### Rust Setup
 
 First, complete the [basic Rust setup instructions](./doc/rust-setup.md).

shell.nix

+let
+  mozillaOverlay =
+    import (builtins.fetchGit {
+      url = "https://github.com/mozilla/nixpkgs-mozilla.git";
+      rev = "57c8084c7ef41366993909c20491e359bbb90f54";
+    });
+  pinned = builtins.fetchGit {
+    # Descriptive name to make the store path easier to identify
+    name = "nixos-unstable-2020-04-26";
+    url = "https://github.com/nixos/nixpkgs/";
+    # Commit hash for nixos-unstable as of 2020-04-26
+    # `git ls-remote https://github.com/nixos/nixpkgs nixos-unstable`
+    ref = "refs/heads/nixos-unstable";
+    rev = "1fe6ed37fd9beb92afe90671c0c2a662a03463dd";
+  };
+  nixpkgs = import pinned { overlays = [ mozillaOverlay ]; };
+  rust-nightly = with nixpkgs; ((rustChannelOf { date = "2021-03-01"; channel = "nightly"; }).rust.override {
+    targets = [ "wasm32-unknown-unknown" ];
+  });
+in
+with nixpkgs; pkgs.mkShell {
+  buildInputs = [
+    clang
+    pkg-config
+    rust-nightly
+  ] ++ stdenv.lib.optionals stdenv.isDarwin [
+    darwin.apple_sdk.frameworks.Security
+  ];
+
+  LIBCLANG_PATH = "${llvmPackages.libclang}/lib";
+  PROTOC = "${protobuf}/bin/protoc";
+  ROCKSDB_LIB_DIR = "${rocksdb}/lib";
+}