feat(proto): Add protobuf & gRPC dependencies via external

Moves the Protobuf & gRPC dependencies to a separate file which uses
buildGo.external to build the dependencies.

The versions are pinned at master of 2019-11-26.

1 files changed, 72 insertions, 0 deletions

diff --git a/proto.nix b/proto.nix
new file mode 100644
index 0000000000..e773af0318
--- /dev/null
+++ b/proto.nix
@@ -0,0 +1,72 @@
+# Copyright 2019 Google LLC.
+# SPDX-License-Identifier: Apache-2.0
+#
+# This file provides derivations for the dependencies of a gRPC
+# service in Go.
+
+{ external }:
+
+let
+  inherit (builtins) fetchGit map;
+in rec {
+  goProto = external {
+    path = "github.com/golang/protobuf";
+    src = fetchGit {
+      url = "https://github.com/golang/protobuf";
+      rev = "ed6926b37a637426117ccab59282c3839528a700";
+    };
+  };
+
+  xnet = external {
+    path = "golang.org/x/net";
+    srcOnly = true;
+    deps = [ xtext ];
+    src = fetchGit {
+      url = "https://go.googlesource.com/net";
+      rev = "ffdde105785063a81acd95bdf89ea53f6e0aac2d";
+    };
+  };
+
+  xsys = external {
+    path = "golang.org/x/sys";
+    srcOnly = true;
+    src = fetchGit {
+      url = "https://go.googlesource.com/sys";
+      rev = "bd437916bb0eb726b873ee8e9b2dcf212d32e2fd";
+    };
+  };
+
+  xtext = external {
+    path = "golang.org/x/text";
+    srcOnly = true;
+    src = fetchGit {
+      url = "https://go.googlesource.com/text";
+      rev = "cbf43d21aaebfdfeb81d91a5f444d13a3046e686";
+    };
+  };
+
+  genproto = external {
+    path = "google.golang.org/genproto";
+    srcOnly = true;
+    src = fetchGit {
+      url = "https://github.com/google/go-genproto";
+      rev = "83cc0476cb11ea0da33dacd4c6354ab192de6fe6";
+    };
+  };
+
+  goGrpc = external {
+    path = "google.golang.org/grpc";
+    deps = [ goProto xnet xsys genproto ];
+
+    src = fetchGit {
+      url = "https://github.com/grpc/grpc-go";
+      rev = "d8e3da36ac481ef00e510ca119f6b68177713689";
+    };
+
+    targets = [
+      "."
+      "codes"
+      "status"
+    ];
+  };
+}