Added nix flake for developer convenience (#2)

.envrc.example

@@ -0,0 +1 @@
+use flake

.gitignore

@@ -1,12 +1,10 @@
-*.egg-info/
 *.DS_Store
-
-target/
+*.egg-info/
+.direnv/
+.docker_image_built
+.envrc
 __pycache__/
+nanopb
 nanopb_out/
-.docker_image_built
-
-# generated
 out.bin
-
-nanopb
+target/

flake.nix

@@ -0,0 +1,48 @@
+{
+  description = "orb-mcu-messaging flake";
+
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs?ref=nixos-unstable";
+    # Provides eachDefaultSystem and other utility functions
+    utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs = { self, nixpkgs, utils }:
+
+    # This helper function is used to more easily abstract
+    # over the host platform.
+    # See https://github.com/numtide/flake-utils#eachdefaultsystem--system---attrs
+    utils.lib.eachDefaultSystem (system:
+      let
+        p = {
+          # The platform that you are running nix on and building from
+          native = nixpkgs.legacyPackages.${system};
+        };
+      in
+      {
+        # Everything in here becomes your shell (nix develop)
+        devShells.default = p.native.mkShell {
+          # Nix makes the following list of dependencies available to the development
+          # environment.
+          buildInputs = (with p.native; [
+            protobuf
+            nixpkgs-fmt
+
+            # This is missing on mac m1 nix, for some reason.
+            # see https://stackoverflow.com/a/69732679
+            libiconv
+          ]);
+
+          # The following sets up environment variables for the shell. These are used
+          # by the build.rs build scripts of the rust crates.
+          shellHook = ''
+            # Env vars here
+          '';
+        };
+        # Lets you type `nix fmt` to format the flake.
+        formatter = p.native.nixpkgs-fmt;
+      }
+
+    );
+
+}