build: Add nix derivation for building cargo workspace

Author: JosephGoulden

flake.lock

@@ -3,7 +3,17 @@
 
   inputs = {
     nixpkgs.url = "github:NixOS/nixpkgs/nixos-24.05";
+
     flake-parts.url = "github:hercules-ci/flake-parts";
+
+    crane.url = "github:ipetkov/crane";
+
+    treefmt-nix.url = "github:numtide/treefmt-nix";
+
+    advisory-db = {
+      url = "github:rustsec/advisory-db";
+      flake = false;
+    };
   };
 
   outputs =
@@ -15,18 +25,25 @@
     }:
     flake-parts.lib.mkFlake { inherit inputs; } {
       systems = nixpkgs.lib.systems.flakeExposed;
+      imports = [
+        inputs.treefmt-nix.flakeModule
+        ./nix/pkgs/flake-module.nix
+        ./nix/checks/flake-module.nix
+        ./nix/shells.nix
+        ./nix/treefmt.nix
+      ];
       perSystem =
         {
           config,
           pkgs,
           self',
+          system,
           ...
         }:
         {
-          packages = rec {
-            # This package depends on git submodules so use a shell command like 'nix build .?submodules=1'.
-            cln = pkgs.callPackage nix/pkgs/default.nix { inherit self pkgs; };
-            default = cln;
+          _module.args.pkgs = import inputs.nixpkgs {
+            inherit system;
+            overlays = [ (final: prev: { craneLib = (inputs.crane.mkLib pkgs); }) ];
           };
           apps = {
             lightningd = {
@@ -42,10 +59,6 @@
               program = "${self'.packages.cln}/bin/reckless";
             };
           };
-          checks = {
-            cln = self'.packages.cln;
-          };
-          formatter = pkgs.nixfmt-rfc-style;
         };
     };
 }

flake.nix

@@ -0,0 +1,19 @@
+{ inputs, self, ... }:
+{
+  perSystem =
+    { pkgs, config, ... }:
+    let
+      advisory-db = inputs.advisory-db;
+    in
+    {
+      checks = {
+        cln = config.packages.cln;
+        rust = config.packages.rust;
+        cargo-audit = pkgs.craneLib.cargoAudit {
+          src = ../../.;
+          inherit advisory-db;
+        };
+        formatting = config.treefmt.build.check self;
+      };
+    };
+}

nix/checks/flake-module.nix

@@ -2,6 +2,7 @@
   self,
   lib,
   pkgs,
+  config,
 }:
 with pkgs;
 let
@@ -28,12 +29,10 @@ stdenv.mkDerivation {
       autoconf
       autogen
       automake
-      cargo
       gettext
       gitMinimal
       libtool
       lowdown
-      protobuf
       py3
       unzip
       which
@@ -83,6 +82,7 @@ stdenv.mkDerivation {
   # The `clnrest` plugin requires a Python environment to run
   postInstall = ''
     rm -r $out/libexec/c-lightning/plugins/clnrest
+    cp ${config.packages.rust}/bin/cln-grpc $out/libexec/c-lightning/plugins
   '';
 
   meta = with lib; {

nix/pkgs/default.nix

@@ -0,0 +1,13 @@
+{ self, ... }:
+{
+  perSystem =
+    { pkgs, config, ... }:
+    {
+      packages = rec {
+        # This package depends on git submodules so use a shell command like 'nix build .?submodules=1'.
+        cln = pkgs.callPackage ./default.nix { inherit self pkgs config; };
+        rust = pkgs.callPackage ./rust.nix { craneLib = pkgs.craneLib; };
+        default = cln;
+      };
+    };
+}

nix/pkgs/flake-module.nix

@@ -0,0 +1,19 @@
+{
+  pkgs,
+  lib,
+  craneLib,
+  ...
+}:
+let
+  version = builtins.readFile ../../.version;
+  src = lib.cleanSourceWith {
+    src = ../../.;
+    filter = path: type: (lib.hasSuffix "\.proto" path) || (craneLib.filterCargoSources path type);
+  };
+in
+craneLib.buildPackage {
+  pname = "rust";
+  inherit src version;
+  strictDeps = true;
+  nativeBuildInputs = with pkgs; [ protobuf ];
+}

nix/pkgs/rust.nix

@@ -0,0 +1,19 @@
+{ self, ... }:
+{
+  perSystem =
+    {
+      config,
+      pkgs,
+      system,
+      ...
+    }:
+    {
+      devShells = {
+        rust = pkgs.craneLib.devShell {
+          checks = {
+            inherit (self.checks.${system}) rust;
+          };
+        };
+      };
+    };
+}

nix/shells.nix

@@ -0,0 +1,11 @@
+{ ... }:
+{
+  perSystem =
+    { pkgs, lib, ... }:
+    {
+      treefmt = {
+        projectRootFile = "flake.nix";
+        programs.nixfmt.enable = true;
+      };
+    };
+}