chore(nix/fetchGoModule): Move //users/edef/fetchGoModule to //nix

Change-Id: Ie7f52367ef91c0c8017a36c2a6c7edb06f10e57d
Reviewed-on: https://cl.tvl.fyi/c/depot/+/1589
Tested-by: BuildkiteCI
Reviewed-by: tazjin <mail@tazj.in>

nix/fetchGoModule/OWNERS

@@ -0,0 +1,2 @@
+owners:
+  - edef

nix/fetchGoModule/default.nix

@@ -0,0 +1,24 @@
+{ pkgs, ... }:
+
+{ path, version, sha256 }:
+
+(pkgs.fetchurl {
+  name = "source";
+  url = "https://proxy.golang.org/${path}/@v/v${version}.zip";
+  inherit sha256;
+
+  recursiveHash = true;
+  downloadToTemp = true;
+
+  postFetch = ''
+    unpackDir="$TMPDIR/unpack"
+    mkdir "$unpackDir"
+    cd "$unpackDir"
+
+    mv "$downloadedFile" "$TMPDIR/src.zip"
+    unpackFile "$TMPDIR/src.zip"
+    mv "$unpackDir/${path}@v${version}" "$out"
+  '';
+}).overrideAttrs ({ nativeBuildInputs ? [], ... }: {
+  nativeBuildInputs = nativeBuildInputs ++ [ pkgs.unzip ];
+})