Add Nix packaging

1 files changed, 387 insertions, 0 deletions

diff --git a/nix/builder/default.nix b/nix/builder/default.nix
new file mode 100644
index 0000000..8b8ae19
--- /dev/null
+++ b/nix/builder/default.nix
@@ -0,0 +1,387 @@
+{ stdenv
+, stdenvNoCC
+, runCommand
+, buildEnv
+, lib
+, fetchgit
+, removeReferencesTo
+, jq
+, cacert
+, pkgs
+, pkgsBuildBuild
+}:
+let
+
+  inherit (builtins) substring toJSON hasAttr trace split readFile elemAt;
+  inherit (lib)
+    concatStringsSep replaceStrings removePrefix optionalString pathExists
+    optional concatMapStrings fetchers filterAttrs mapAttrs mapAttrsToList
+    warnIf optionalAttrs platforms
+    ;
+
+  parseGoMod = import ./parser.nix;
+
+  removeExpr = refs: ''remove-references-to ${concatMapStrings (ref: " -t ${ref}") refs}'';
+
+  # Internal only build-time attributes
+  internal =
+    let
+      mkInternalPkg = name: src: pkgsBuildBuild.runCommand "gomod2nix-${name}"
+        {
+          inherit (pkgsBuildBuild.go) GOOS GOARCH;
+          nativeBuildInputs = [ pkgsBuildBuild.go ];
+        } ''
+        export HOME=$(mktemp -d)
+        cp ${src} src.go
+        go build -o $out src.go
+      '';
+    in
+    {
+
+      # Create a symlink tree of vendored sources
+      symlink = mkInternalPkg "symlink" ./symlink/symlink.go;
+
+      # Install development dependencies from tools.go
+      install = mkInternalPkg "symlink" ./install/install.go;
+
+    };
+
+  fetchGoModule =
+    { hash
+    , goPackagePath
+    , version
+    , go ? pkgs.go
+    }:
+    stdenvNoCC.mkDerivation {
+      name = "${baseNameOf goPackagePath}_${version}";
+      builder = ./fetch.sh;
+      inherit goPackagePath version;
+      nativeBuildInputs = [ go jq ];
+      outputHashMode = "recursive";
+      outputHashAlgo = null;
+      outputHash = hash;
+      SSL_CERT_FILE = "${cacert}/etc/ssl/certs/ca-bundle.crt";
+      impureEnvVars = fetchers.proxyImpureEnvVars ++ [ "GOPROXY" ];
+    };
+
+  mkVendorEnv =
+    { go
+    , modulesStruct
+    , localReplaceCommands ? [ ]
+    , defaultPackage ? ""
+    , goMod
+    , pwd
+    }:
+    let
+      localReplaceCommands =
+        let
+          localReplaceAttrs = filterAttrs (n: v: hasAttr "path" v) goMod.replace;
+          commands = (
+            mapAttrsToList
+              (name: value: (
+                ''
+                  mkdir -p $(dirname vendor/${name})
+                  ln -s ${pwd + "/${value.path}"} vendor/${name}
+                ''
+              ))
+              localReplaceAttrs);
+        in
+        if goMod != null then commands else [ ];
+
+      sources = mapAttrs
+        (goPackagePath: meta: fetchGoModule {
+          goPackagePath = meta.replaced or goPackagePath;
+          inherit (meta) version hash;
+          inherit go;
+        })
+        modulesStruct.mod;
+    in
+    runCommand "vendor-env"
+      {
+        nativeBuildInputs = [ go ];
+        json = toJSON (filterAttrs (n: _: n != defaultPackage) modulesStruct.mod);
+
+        sources = toJSON (filterAttrs (n: _: n != defaultPackage) sources);
+
+        passthru = {
+          inherit sources;
+        };
+
+        passAsFile = [ "json" "sources" ];
+      }
+      (
+        ''
+          mkdir vendor
+
+          export GOCACHE=$TMPDIR/go-cache
+          export GOPATH="$TMPDIR/go"
+
+          ${internal.symlink}
+          ${concatStringsSep "\n" localReplaceCommands}
+
+          mv vendor $out
+        ''
+      );
+
+  # Select Go attribute based on version specified in go.mod
+  selectGo = attrs: goMod: attrs.go or (if goMod == null then pkgs.go else
+  (
+    let
+      goVersion = goMod.go;
+      goAttr = "go_" + (replaceStrings [ "." ] [ "_" ] goVersion);
+    in
+    (
+      if hasAttr goAttr pkgs then pkgs.${goAttr}
+      else trace "go.mod specified Go version ${goVersion} but doesn't exist. Falling back to ${pkgs.go.version}." pkgs.go
+    )
+  ));
+
+  # Strip the rubbish that Go adds to versions, and fall back to a version based on the date if it's a placeholder value
+  stripVersion = version:
+    let
+      parts = elemAt (split "(\\+|-)" (removePrefix "v" version));
+      v = parts 0;
+      d = parts 2;
+    in
+    if v != "0.0.0" then v else "unstable-" + (concatStringsSep "-" [
+      (substring 0 4 d)
+      (substring 4 2 d)
+      (substring 6 2 d)
+    ]);
+
+  mkGoEnv =
+    { pwd
+    }@attrs:
+    let
+      goMod = parseGoMod (readFile "${toString pwd}/go.mod");
+      modulesStruct = fromTOML (readFile "${toString pwd}/gomod2nix.toml");
+
+      go = selectGo attrs goMod;
+
+      vendorEnv = mkVendorEnv {
+        inherit go modulesStruct pwd goMod;
+      };
+
+    in
+    stdenv.mkDerivation (removeAttrs attrs [ "pwd" ] // {
+      name = "${baseNameOf goMod.module}-env";
+
+      dontUnpack = true;
+      dontConfigure = true;
+      dontInstall = true;
+
+      propagatedNativeBuildInputs = [ go ];
+
+      GO_NO_VENDOR_CHECKS = "1";
+
+      GO111MODULE = "on";
+      GOFLAGS = "-mod=vendor";
+
+      preferLocalBuild = true;
+
+      buildPhase = ''
+        mkdir $out
+
+        export GOCACHE=$TMPDIR/go-cache
+        export GOPATH="$out"
+        export GOSUMDB=off
+        export GOPROXY=off
+
+      '' + optionalString (pathExists (pwd + "/tools.go")) ''
+        mkdir source
+        cp ${pwd + "/go.mod"} source/go.mod
+        cp ${pwd + "/go.sum"} source/go.sum
+        cp ${pwd + "/tools.go"} source/tools.go
+        cd source
+        ln -s ${vendorEnv} vendor
+
+        ${internal.install}
+      '';
+    });
+
+  buildGoApplication =
+    { modules ? pwd + "/gomod2nix.toml"
+    , src ? pwd
+    , pwd ? null
+    , nativeBuildInputs ? [ ]
+    , allowGoReference ? false
+    , meta ? { }
+    , passthru ? { }
+    , tags ? [ ]
+
+      # needed for buildFlags{,Array} warning
+    , buildFlags ? ""
+    , buildFlagsArray ? ""
+
+    , ...
+    }@attrs:
+    let
+      modulesStruct = fromTOML (readFile modules);
+
+      goModPath = "${toString pwd}/go.mod";
+
+      goMod =
+        if pwd != null && pathExists goModPath
+        then parseGoMod (readFile goModPath)
+        else null;
+
+      go = selectGo attrs goMod;
+
+      removeReferences = [ ] ++ optional (!allowGoReference) go;
+
+      defaultPackage = modulesStruct.goPackagePath or "";
+
+      vendorEnv = mkVendorEnv {
+        inherit go modulesStruct defaultPackage goMod pwd;
+      };
+
+    in
+    warnIf (buildFlags != "" || buildFlagsArray != "")
+      "Use the `ldflags` and/or `tags` attributes instead of `buildFlags`/`buildFlagsArray`"
+      stdenv.mkDerivation
+      (optionalAttrs (defaultPackage != "")
+        {
+          pname = attrs.pname or baseNameOf defaultPackage;
+          version = stripVersion (modulesStruct.mod.${defaultPackage}).version;
+          src = vendorEnv.passthru.sources.${defaultPackage};
+        } // optionalAttrs (hasAttr "subPackages" modulesStruct) {
+        subPackages = modulesStruct.subPackages;
+      } // attrs // {
+        nativeBuildInputs = [ removeReferencesTo go ] ++ nativeBuildInputs;
+
+        inherit (go) GOOS GOARCH;
+
+        GO_NO_VENDOR_CHECKS = "1";
+
+        GO111MODULE = "on";
+        GOFLAGS = "-mod=vendor";
+
+        configurePhase = attrs.configurePhase or ''
+          runHook preConfigure
+
+          export GOCACHE=$TMPDIR/go-cache
+          export GOPATH="$TMPDIR/go"
+          export GOSUMDB=off
+          export GOPROXY=off
+          cd "$modRoot"
+          if [ -n "${vendorEnv}" ]; then
+              rm -rf vendor
+              ln -s ${vendorEnv} vendor
+          fi
+
+          runHook postConfigure
+        '';
+
+        buildPhase = attrs.buildPhase or ''
+          runHook preBuild
+
+          exclude='\(/_\|examples\|Godeps\|testdata'
+          if [[ -n "$excludedPackages" ]]; then
+            IFS=' ' read -r -a excludedArr <<<$excludedPackages
+            printf -v excludedAlternates '%s\\|' "''${excludedArr[@]}"
+            excludedAlternates=''${excludedAlternates%\\|} # drop final \| added by printf
+            exclude+='\|'"$excludedAlternates"
+          fi
+          exclude+='\)'
+
+          buildGoDir() {
+            local d; local cmd;
+            cmd="$1"
+            d="$2"
+            . $TMPDIR/buildFlagsArray
+            local OUT
+            if ! OUT="$(go $cmd $buildFlags "''${buildFlagsArray[@]}" ''${tags:+-tags=${concatStringsSep "," tags}} ''${ldflags:+-ldflags="$ldflags"} -v -p $NIX_BUILD_CORES $d 2>&1)"; then
+              if echo "$OUT" | grep -qE 'imports .*?: no Go files in'; then
+                echo "$OUT" >&2
+                return 1
+              fi
+              if ! echo "$OUT" | grep -qE '(no( buildable| non-test)?|build constraints exclude all) Go (source )?files'; then
+                echo "$OUT" >&2
+                return 1
+              fi
+            fi
+            if [ -n "$OUT" ]; then
+              echo "$OUT" >&2
+            fi
+            return 0
+          }
+
+          getGoDirs() {
+            local type;
+            type="$1"
+            if [ -n "$subPackages" ]; then
+              echo "$subPackages" | sed "s,\(^\| \),\1./,g"
+            else
+              find . -type f -name \*$type.go -exec dirname {} \; | grep -v "/vendor/" | sort --unique | grep -v "$exclude"
+            fi
+          }
+
+          if (( "''${NIX_DEBUG:-0}" >= 1 )); then
+            buildFlagsArray+=(-x)
+          fi
+
+          if [ ''${#buildFlagsArray[@]} -ne 0 ]; then
+            declare -p buildFlagsArray > $TMPDIR/buildFlagsArray
+          else
+            touch $TMPDIR/buildFlagsArray
+          fi
+          if [ -z "$enableParallelBuilding" ]; then
+              export NIX_BUILD_CORES=1
+          fi
+          for pkg in $(getGoDirs ""); do
+            echo "Building subPackage $pkg"
+            buildGoDir install "$pkg"
+          done
+        '' + optionalString (stdenv.hostPlatform != stdenv.buildPlatform) ''
+          # normalize cross-compiled builds w.r.t. native builds
+          (
+            dir=$GOPATH/bin/${go.GOOS}_${go.GOARCH}
+            if [[ -n "$(shopt -s nullglob; echo $dir/*)" ]]; then
+              mv $dir/* $dir/..
+            fi
+            if [[ -d $dir ]]; then
+              rmdir $dir
+            fi
+          )
+        '' + ''
+          runHook postBuild
+        '';
+
+        doCheck = attrs.doCheck or true;
+        checkPhase = attrs.checkPhase or ''
+          runHook preCheck
+
+          for pkg in $(getGoDirs test); do
+            buildGoDir test $checkFlags "$pkg"
+          done
+
+          runHook postCheck
+        '';
+
+        installPhase = attrs.installPhase or ''
+          runHook preInstall
+
+          mkdir -p $out
+          dir="$GOPATH/bin"
+          [ -e "$dir" ] && cp -r $dir $out
+
+          runHook postInstall
+        '';
+
+        preFixup = (attrs.preFixup or "") + ''
+          find $out/{bin,libexec,lib} -type f 2>/dev/null | xargs -r ${removeExpr removeReferences} || true
+        '';
+
+        strictDeps = true;
+
+        disallowedReferences = optional (!allowGoReference) go;
+
+        passthru = { inherit go vendorEnv; } // passthru;
+
+        meta = { platforms = go.meta.platforms or platforms.all; } // meta;
+      });
+
+in
+{
+  inherit buildGoApplication mkGoEnv;
+}