flake: add Nix flake for reproducible builds (#1096)

Co-authored-by: loverustfs <hello@rustfs.com>
Co-authored-by: 0xdx2 <xuedamon2@gmail.com>

flake.lock

@@ -0,0 +1,27 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1765270179,
+        "narHash": "sha256-g2a4MhRKu4ymR4xwo+I+auTknXt/+j37Lnf0Mvfl1rE=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "677fbe97984e7af3175b6c121f3c39ee5c8d62c9",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixpkgs-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,66 @@
+# Nix flake for building RustFS
+#
+# Prerequisites:
+#   Install Nix: https://nixos.org/download/
+#   Enable flakes: https://nixos.wiki/wiki/Flakes#Enable_flakes
+#
+# Usage:
+#   nix build          # Build rustfs binary
+#   nix run            # Build and run rustfs
+#   ./result/bin/rustfs --help
+{
+  description = "RustFS - High-performance S3-compatible object storage";
+
+  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
+
+  outputs =
+    { nixpkgs, ... }:
+    let
+      systems = [
+        "x86_64-linux"
+        "aarch64-linux"
+        "x86_64-darwin"
+        "aarch64-darwin"
+      ];
+      forAllSystems = nixpkgs.lib.genAttrs systems;
+    in
+    {
+      packages = forAllSystems (
+        system:
+        let
+          pkgs = nixpkgs.legacyPackages.${system};
+        in
+        {
+          default = pkgs.rustPlatform.buildRustPackage {
+            pname = "rustfs";
+            version = "0.0.5";
+
+            src = ./.;
+
+            cargoLock.lockFile = ./Cargo.lock;
+
+            nativeBuildInputs = with pkgs; [
+              pkg-config
+              protobuf
+            ];
+
+            buildInputs = with pkgs; [ openssl ];
+
+            cargoBuildFlags = [
+              "--package"
+              "rustfs"
+            ];
+
+            doCheck = false;
+
+            meta = {
+              description = "High-performance S3-compatible object storage";
+              homepage = "https://rustfs.com";
+              license = pkgs.lib.licenses.asl20;
+              mainProgram = "rustfs";
+            };
+          };
+        }
+      );
+    };
+}