feat(tools): Add 'gotest' program to demonstrate pkgs.buildGo

This is a tiny program that does nothing but exists to demonstrate
pkgs.buildGo by building a program that depends on a local library as
well as a protobuf definition.

4 files changed, 63 insertions, 0 deletions

diff --git a/tools/gotest/default.nix b/tools/gotest/default.nix
new file mode 100644
index 000000000000..4396cd9b47c9
--- /dev/null
+++ b/tools/gotest/default.nix
@@ -0,0 +1,27 @@
+# This file demonstrates how to make use of pkgs.buildGo.
+#
+# It introduces libraries and protobuf support, however gRPC support
+# is not yet included.
+#
+# From the root of this repository this example can be built with
+# `nix-build -A tools.gotest`
+{ pkgs, ... }:
+
+let
+  inherit (pkgs) buildGo;
+
+  somelib = buildGo.package {
+    name = "somelib";
+    srcs = [ ./lib.go ];
+  };
+
+  someproto = buildGo.proto {
+    name = "someproto";
+    proto = ./test.proto;
+  };
+
+in buildGo.program {
+  name = "gotest";
+  srcs = [ ./main.go ];
+  deps = [ somelib someproto ];
+}
diff --git a/tools/gotest/lib.go b/tools/gotest/lib.go
new file mode 100644
index 000000000000..0aeebb2aea69
--- /dev/null
+++ b/tools/gotest/lib.go
@@ -0,0 +1,11 @@
+package somelib
+
+import "fmt"
+
+func Name() string {
+	return "edef"
+}
+
+func Greet(s string) string {
+	return fmt.Sprintf("Hello %s", s)
+}
diff --git a/tools/gotest/main.go b/tools/gotest/main.go
new file mode 100644
index 000000000000..99218c077617
--- /dev/null
+++ b/tools/gotest/main.go
@@ -0,0 +1,16 @@
+// This program just exists to import some libraries and demonstrate
+// that the build works, it doesn't do anything useful.
+package main
+
+import (
+	"fmt"
+	"somelib"
+	"someproto"
+)
+
+func main() {
+	p := someproto.Person{
+		Name: somelib.Name(),
+	}
+	fmt.Println(somelib.Greet(fmt.Sprintf("%v", p)))
+}
diff --git a/tools/gotest/test.proto b/tools/gotest/test.proto
new file mode 100644
index 000000000000..76af63072be3
--- /dev/null
+++ b/tools/gotest/test.proto
@@ -0,0 +1,9 @@
+syntax = "proto3";
+package someproto;
+
+import "google/protobuf/timestamp.proto";
+
+message Person {
+  string name = 1;
+  google.protobuf.Timestamp last_updated = 2;
+}