Refactor default.nix to follow Nix Flakes patterns

1 files changed, 22 insertions, 139 deletions

diff --git a/default.nix b/default.nix
index 296c7592..5634f0af 100644
--- a/default.nix
+++ b/default.nix
@@ -1,149 +1,32 @@
 {
   system ? builtins.currentSystem,
-  release ? false,
-  target ? "x86_64-unknown-linux-musl",
-  compileMode ? null,
   git_version ? null,
 }:
 
 with import ./nix/common.nix;
 
-let
-  crossSystem = { config = target; };
-in let
-  log = v: builtins.trace v v;
-
-  pkgs = import pkgsSrc {
-    inherit system crossSystem;
-    overlays = [ cargo2nixOverlay ];
-  };
-
-
-  /*
-   Rust and Nix triples are not the same. Cargo2nix has a dedicated library
-   to convert Nix triples to Rust ones. We need this conversion as we want to
-   set later options linked to our (rust) target in a generic way. Not only
-   the triple terminology is different, but also the "roles" are named differently.
-   Nix uses a build/host/target terminology where Nix's "host" maps to Cargo's "target".
-  */
-  rustTarget = log (pkgs.rustBuilder.rustLib.rustTriple pkgs.stdenv.hostPlatform);
-
-  /*
-   Cargo2nix is built for rustOverlay which installs Rust from Mozilla releases.
-   We want our own Rust to avoid incompatibilities, like we had with musl 1.2.0.
-   rustc was built with musl < 1.2.0 and nix shipped musl >= 1.2.0 which lead to compilation breakage.
-   So we want a Rust release that is bound to our Nix repository to avoid these problems.
-   See here for more info: https://musl.libc.org/time64.html
-   Because Cargo2nix does not support the Rust environment shipped by NixOS,
-   we emulate the structure of the Rust object created by rustOverlay.
-   In practise, rustOverlay ships rustc+cargo in a single derivation while
-   NixOS ships them in separate ones. We reunite them with symlinkJoin.
-   */
-  rustChannel = pkgs.symlinkJoin {
-    name ="rust-channel";
-    paths = [ 
-      pkgs.rustPlatform.rust.rustc
-      pkgs.rustPlatform.rust.cargo
-    ];
+let 
+  compile = import ./nix/compile.nix;
+  build_debug_and_release = (target: {
+    debug = (compile { inherit target; release = false; }).workspace.garage { compileMode = "build"; }; 
+    release = (compile { inherit target; release = true; }).workspace.garage { compileMode = "build"; }; 
+  });
+
+in {
+  pkgs = {
+    amd64 = build_debug_and_release "x86_64-unknown-linux-musl";
+    i386 = build_debug_and_release "i686-unknown-linux-musl";
+    arm64 = build_debug_and_release "aarch64-unknown-linux-musl";
+    arm = build_debug_and_release "armv6l-unknown-linux-musleabihf";
   };
-
-  /*
-   Cargo2nix provides many overrides by default, you can take inspiration from them:
-   https://github.com/cargo2nix/cargo2nix/blob/master/overlay/overrides.nix
-
-   You can have a complete list of the available options by looking at the overriden object, mkcrate:
-   https://github.com/cargo2nix/cargo2nix/blob/master/overlay/mkcrate.nix
-  */
-  overrides = pkgs.rustBuilder.overrides.all ++ [
-    /*
-     [1] We need to alter Nix hardening to make static binaries: PIE,
-     Position Independent Executables seems to be supported only on amd64. Having
-     this flag set either 1. make our executables crash or 2. compile as dynamic on some platforms.
-     Here, we deactivate it. Later (find `codegenOpts`), we reactivate it for supported targets
-     (only amd64 curently) through the `-static-pie` flag.
-     PIE is a feature used by ASLR, which helps mitigate security issues.
-     Learn more about Nix Hardening at: https://github.com/NixOS/nixpkgs/blob/master/pkgs/build-support/cc-wrapper/add-hardening.sh
-    */
-    (pkgs.rustBuilder.rustLib.makeOverride {
-      name = "garage";
-      overrideAttrs = drv: { hardeningDisable = [ "pie" ]; };
-    })
-
-    (pkgs.rustBuilder.rustLib.makeOverride {
-      name = "garage_rpc";
-
-      /*
-       [2] We want to inject the git version while keeping the build deterministic.
-       As we do not want to consider the .git folder as part of the input source,
-       we ask the user (the CI often) to pass the value to Nix.
-      */
-      overrideAttrs = drv:
-        (if git_version != null then {
-          preConfigure = ''
-            ${drv.preConfigure or ""}
-            export GIT_VERSION="${git_version}"
-          '';
-        } else {});
-
-      /*
-       [3] We ship some parts of the code disabled by default by putting them behind a flag.
-       It speeds up the compilation (when the feature is not required) and released crates have less dependency by default (less attack surface, disk space, etc.).
-       But we want to ship these additional features when we release Garage.
-       In the end, we chose to exclude all features from debug builds while putting (all of) them in the release builds.
-       Currently, the only feature of Garage is kubernetes-discovery from the garage_rpc crate.
-      */
-      overrideArgs = old: {
-        features = if release then [ "kubernetes-discovery" ] else [];
+  test = {
+    amd64 = let
+        pkgs = import pkgsSrc { };
+        rustPkgs = compile { target = "x86_64-unknown-linux-musl"; }; 
+      in
+      pkgs.symlinkJoin {
+        name ="garage-tests";
+        paths = builtins.map (key: rustPkgs.workspace.${key} { compileMode = "test"; }) (builtins.attrNames rustPkgs.workspace);
       };
-    })
-
-  ];
-
-  packageFun = import ./Cargo.nix;
-
-  /*
-    We compile fully static binaries with musl to simplify deployment on most systems.
-    When possible, we reactivate PIE hardening (see above).
-
-    Also, if you set the RUSTFLAGS environment variable, the following parameters will
-    be ignored.
-
-    For more information on static builds, please refer to Rust's RFC 1721.
-    https://rust-lang.github.io/rfcs/1721-crt-static.html#specifying-dynamicstatic-c-runtime-linkage
-  */
-
-  codegenOpts = {
-   "armv6l-unknown-linux-musleabihf" = [ "target-feature=+crt-static" "link-arg=-static" ]; /* compile as dynamic with static-pie */
-   "aarch64-unknown-linux-musl" = [ "target-feature=+crt-static" "link-arg=-static" ]; /* segfault with static-pie */
-   "i686-unknown-linux-musl" = [ "target-feature=+crt-static" "link-arg=-static" ]; /* segfault with static-pie */
-   "x86_64-unknown-linux-musl" = [ "target-feature=+crt-static" "link-arg=-static-pie" ];
   };
-
-  /*
-   The following definition is not elegant as we use a low level function of Cargo2nix
-   that enables us to pass our custom rustChannel object. We need this low level definition
-   to pass Nix's Rust toolchains instead of Mozilla's one.
-
-   target is mandatory but must be kept to null to allow cargo2nix to set it to the appropriate value
-   for each crate.
-  */ 
-  rustPkgs = pkgs.rustBuilder.makePackageSet {
-    inherit packageFun rustChannel release codegenOpts;
-    packageOverrides = overrides;
-    target = null;
-
-    buildRustPackages = pkgs.buildPackages.rustBuilder.makePackageSet {
-      inherit rustChannel packageFun codegenOpts;
-      packageOverrides = overrides;
-      target = null;
-    };
-  };
-
-
-in
-  if compileMode == "test"
-    then pkgs.symlinkJoin {
-      name ="garage-tests";
-      paths = builtins.map (key: rustPkgs.workspace.${key} { inherit compileMode; }) (builtins.attrNames rustPkgs.workspace);
-    }
-    else rustPkgs.workspace.garage { inherit compileMode; }
+}