From e76dba9561128fb8eb26820214a3d103e7f5f9d1 Mon Sep 17 00:00:00 2001
From: Alex Auvolat <alex@adnab.me>
Date: Wed, 16 Nov 2022 22:21:24 +0100
Subject: [PATCH] Make repository into a Nix flake

---
 default.nix     |   8 ++--
 flake.lock      | 108 ++++++++++++++++++++++++++++++++++++++++++++++++
 flake.nix       |  28 +++++++++++++
 nix/compile.nix |  33 +++++++++------
 shell.nix       |   2 +-
 5 files changed, 161 insertions(+), 18 deletions(-)
 create mode 100644 flake.lock
 create mode 100644 flake.nix

diff --git a/default.nix b/default.nix
index 60a85e2f..1791b3c6 100644
--- a/default.nix
+++ b/default.nix
@@ -11,14 +11,14 @@ let
 
   build_debug_and_release = (target: {
     debug = (compile {
-      inherit target git_version;
+      inherit system target git_version pkgsSrc cargo2nixOverlay;
       release = false;
     }).workspace.garage {
       compileMode = "build";
     };
 
     release = (compile {
-      inherit target git_version;
+      inherit system target git_version pkgsSrc cargo2nixOverlay;
       release = true;
     }).workspace.garage {
       compileMode = "build";
@@ -39,7 +39,7 @@ in {
   };
   test = {
     amd64 = test (compile {
-      inherit git_version;
+      inherit system git_version pkgsSrc cargo2nixOverlay;
       target = "x86_64-unknown-linux-musl";
       features = [
         "garage/bundled-libs"
@@ -52,7 +52,7 @@ in {
   };
   clippy = {
     amd64 = (compile {
-      inherit git_version;
+      inherit system git_version pkgsSrc cargo2nixOverlay;
       target = "x86_64-unknown-linux-musl";
       compiler = "clippy";
     }).workspace.garage {
diff --git a/flake.lock b/flake.lock
new file mode 100644
index 00000000..4b5713dc
--- /dev/null
+++ b/flake.lock
@@ -0,0 +1,108 @@
+{
+  "nodes": {
+    "cargo2nix": {
+      "inputs": {
+        "flake-compat": "flake-compat",
+        "flake-utils": "flake-utils",
+        "nixpkgs": [
+          "nixpkgs"
+        ],
+        "rust-overlay": "rust-overlay"
+      },
+      "locked": {
+        "lastModified": 1666087781,
+        "narHash": "sha256-trKVdjMZ8mNkGfLcY5LsJJGtdV3xJDZnMVrkFjErlcs=",
+        "owner": "Alexis211",
+        "repo": "cargo2nix",
+        "rev": "a7a61179b66054904ef6a195d8da736eaaa06c36",
+        "type": "github"
+      },
+      "original": {
+        "owner": "Alexis211",
+        "repo": "cargo2nix",
+        "rev": "a7a61179b66054904ef6a195d8da736eaaa06c36",
+        "type": "github"
+      }
+    },
+    "flake-compat": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1650374568,
+        "narHash": "sha256-Z+s0J8/r907g149rllvwhb4pKi8Wam5ij0st8PwAh+E=",
+        "owner": "edolstra",
+        "repo": "flake-compat",
+        "rev": "b4a34015c698c7793d592d66adbab377907a2be8",
+        "type": "github"
+      },
+      "original": {
+        "owner": "edolstra",
+        "repo": "flake-compat",
+        "type": "github"
+      }
+    },
+    "flake-utils": {
+      "locked": {
+        "lastModified": 1659877975,
+        "narHash": "sha256-zllb8aq3YO3h8B/U0/J1WBgAL8EX5yWf5pMj3G0NAmc=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "c0e246b9b83f637f4681389ecabcb2681b4f3af0",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1665657542,
+        "narHash": "sha256-mojxNyzbvmp8NtVtxqiHGhRfjCALLfk9i/Uup68Y5q8=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "a3073c49bc0163fea6a121c276f526837672b555",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "a3073c49bc0163fea6a121c276f526837672b555",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "cargo2nix": "cargo2nix",
+        "nixpkgs": "nixpkgs"
+      }
+    },
+    "rust-overlay": {
+      "inputs": {
+        "flake-utils": [
+          "cargo2nix",
+          "flake-utils"
+        ],
+        "nixpkgs": [
+          "cargo2nix",
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1664247556,
+        "narHash": "sha256-J4vazHU3609ekn7dr+3wfqPo5WGlZVAgV7jfux352L0=",
+        "owner": "oxalica",
+        "repo": "rust-overlay",
+        "rev": "524db9c9ea7bc7743bb74cdd45b6d46ea3fcc2ab",
+        "type": "github"
+      },
+      "original": {
+        "owner": "oxalica",
+        "repo": "rust-overlay",
+        "type": "github"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}
diff --git a/flake.nix b/flake.nix
new file mode 100644
index 00000000..b862e8e6
--- /dev/null
+++ b/flake.nix
@@ -0,0 +1,28 @@
+{
+  description = "Garage, an S3-compatible distributed object store for self-hosted deployments";
+
+  inputs.nixpkgs.url = "github:NixOS/nixpkgs/a3073c49bc0163fea6a121c276f526837672b555";
+  inputs.cargo2nix = {
+    # As of 2022-10-18: two small patches over unstable branch, one for clippy and one to fix feature detection
+    url = "github:Alexis211/cargo2nix/a7a61179b66054904ef6a195d8da736eaaa06c36";
+    inputs.nixpkgs.follows = "nixpkgs";
+  };
+
+  outputs = { self, nixpkgs, cargo2nix }: let
+    git_version = "v0.8.0-rc2";
+    compile = import ./nix/compile.nix;
+    forAllSystems = nixpkgs.lib.genAttrs nixpkgs.lib.systems.flakeExposed;
+  in
+  {
+    packages = forAllSystems (system: {
+      default = (compile {
+        inherit system git_version;
+        pkgsSrc = nixpkgs;
+        cargo2nixOverlay = cargo2nix.overlays.default;
+        release = true;
+      }).workspace.garage {
+        compileMode = "build";
+      };
+    });
+  };
+}
diff --git a/nix/compile.nix b/nix/compile.nix
index 303c3aa4..3ea5035e 100644
--- a/nix/compile.nix
+++ b/nix/compile.nix
@@ -1,25 +1,32 @@
 {
-  system ? builtins.currentSystem,
-  target,
+  system,
+  target ? null,
+  pkgsSrc,
+  cargo2nixOverlay,
   compiler ? "rustc",
   release ? false,
   git_version ? null,
   features ? null,
 }:
 
-with import ./common.nix;
-
 let
   log = v: builtins.trace v v;
 
-  pkgs = import pkgsSrc {
-    inherit system;
-    crossSystem = {
-      config = target;
-      isStatic = true;
-    };
-    overlays = [ cargo2nixOverlay ];
-  };
+  pkgs =
+    if target != null then
+      import pkgsSrc {
+        inherit system;
+        crossSystem = {
+          config = target;
+          isStatic = true;
+        };
+        overlays = [ cargo2nixOverlay ];
+      }
+    else
+      import pkgsSrc {
+        inherit system;
+        overlays = [ cargo2nixOverlay ];
+      };
 
   /*
    Cargo2nix is built for rustOverlay which installs Rust from Mozilla releases.
@@ -34,7 +41,7 @@ let
    NixOS ships them in separate ones. We reunite them with symlinkJoin.
   */
   toolchainOptions =
-    if target == "x86_64-unknown-linux-musl" || target == "aarch64-unknown-linux-musl" then {
+    if target == null || target == "x86_64-unknown-linux-musl" || target == "aarch64-unknown-linux-musl" then {
       rustVersion = "1.63.0";
       extraRustComponents = [ "clippy" ];
     } else {
diff --git a/shell.nix b/shell.nix
index 480bc349..5cece8ad 100644
--- a/shell.nix
+++ b/shell.nix
@@ -1,5 +1,5 @@
 {
-  system ? builtins.currentSystem,
+    system ? builtins.currentSystem,
 }:
 
 with import ./nix/common.nix;