Basic scaffolding in preparation for a binary

nix/cardano-graphql-binary/default.nix

@@ -0,0 +1,13 @@
+{ pkgs, nodejs }:
+
+let
+  nodeEnv = import ./node-env.nix {
+    inherit (pkgs) stdenv python2 utillinux runCommand writeTextFile;
+    inherit nodejs;
+    libtool = if pkgs.stdenv.isDarwin then pkgs.darwin.cctools else null;
+  };
+in
+import ./node-packages.nix {
+  inherit (pkgs) fetchurl fetchgit;
+  inherit nodeEnv;
+}

nix/cardano-graphql-binary/impure.nix

@@ -0,0 +1,57 @@
+{ stdenv, lib, fetchurl }:
+
+stdenv.mkDerivation rec {
+  pname = "cardano-graphql";
+  version = "1.2.1";
+  src = fetchurl {
+    url = "https://github.com/hasura/graphql-engine/releases/download/v${version}/cli-ext-hasura-linux.tar.gz";
+    sha256 = "013m4f56mf2rx6mjkfki64xblvjjcwb0n70ny8wykwqzj5cp1pr5";
+  };
+  sourceRoot = ".";
+  buildPhase = ":";
+  installPhase = ''
+    mkdir -p $out/bin
+    cp cli-ext-hasura-linux $out/bin/
+  '';
+  preFixup = let
+    libPath = lib.makeLibraryPath [ stdenv.cc.cc ];
+  in ''
+    orig_size=$(stat --printf=%s $out/bin/cli-ext-hasura-linux)
+
+    patchelf --set-interpreter "$(cat $NIX_CC/nix-support/dynamic-linker)" $out/bin/cli-ext-hasura-linux
+    patchelf --set-rpath ${libPath} $out/bin/cli-ext-hasura-linux
+    new_size=$(stat --printf=%s $out/bin/cli-ext-hasura-linux)
+
+    ###### zeit-pkg fixing starts here.
+    # we're replacing plaintext js code that looks like
+    # PAYLOAD_POSITION = '1234                  ' | 0
+    # [...]
+    # PRELUDE_POSITION = '1234                  ' | 0
+    # ^-----20-chars-----^^------22-chars------^
+    # ^-- grep points here
+    #
+    # var_* are as described above
+    # shift_by seems to be safe so long as all patchelf adjustments occur
+    # before any locations pointed to by hardcoded offsets
+
+    var_skip=20
+    var_select=22
+    shift_by=$(expr $new_size - $orig_size)
+
+    function fix_offset {
+      # $1 = name of variable to adjust
+      location=$(grep -obUam1 "$1" $out/bin/cli-ext-hasura-linux | cut -d: -f1)
+      location=$(expr $location + $var_skip)
+
+      value=$(dd if=$out/bin/cli-ext-hasura-linux iflag=count_bytes,skip_bytes skip=$location \
+                 bs=1 count=$var_select status=none)
+      value=$(expr $shift_by + $value)
+
+      echo -n $value | dd of=$out/bin/cli-ext-hasura-linux bs=1 seek=$location conv=notrunc
+    }
+
+    fix_offset PAYLOAD_POSITION
+    fix_offset PRELUDE_POSITION
+  '';
+  dontStrip = true;
+}