Add script to update vendored go libs

go/README.md

@@ -4,3 +4,15 @@ This directory contains Go executables for use in gitlab-shell. To add
 a new command `foobar` create a subdirectory `cmd/foobar` and put your
 code in `package main` under `cmd/foobar`. This will automatically get
 compiled into `bin/foobar` by `../bin/compile`.
+
+## Vendoring
+
+We use vendoring in order to include third-party Go libraries. This
+project uses [govendor](https://github.com/kardianos/govendor).
+
+To update e.g. `gitaly-proto` run the following command in the root
+directory of the project.
+
+```
+support/go-update-vendor gitlab.com/gitlab-org/gitaly-proto/go@v0.109.0
+```

support/go-update-vendor

+#!/usr/bin/env ruby
+
+require 'fileutils'
+
+require_relative 'go_build'
+include GoBuild
+
+def main(dependency)
+  # Govendor wants to run in a GOPATH so let's make one for it.
+  create_fresh_build_dir
+  run!(GO_ENV, %w[go get github.com/kardianos/govendor])
+
+  gitlab_shell_build_go_dir = File.join(BUILD_DIR, 'src', GO_PACKAGE)
+  run!(GO_ENV, %W[govendor fetch #{dependency}], chdir: gitlab_shell_build_go_dir)
+
+  # Now we have updated go/vendor in the temporary build dir. We must sync
+  # the changes back so that Git will see them.
+  FileUtils.rm_rf('go/vendor')
+  FileUtils.cp_r(File.join(gitlab_shell_build_go_dir, 'vendor'), 'go')
+end
+
+unless ARGV.count == 1
+  abort "usage: #{$PROGRAM_NAME} DEPENDENCY"
+end
+
+main(ARGV.first)

support/go_build.rb

@@ -22,11 +22,11 @@ module GoBuild
     FileUtils.cp_r(File.join(ROOT_PATH, GO_DIR, '.'), build_source_dir)
   end
 
-  def run!(env, cmd)
+  def run!(env, cmd, options = {})
     raise "env must be a hash" unless env.is_a?(Hash)
     raise "cmd must be an array" unless cmd.is_a?(Array)
 
-    unless system(env, *cmd)
+    unless system(env, *cmd, options)
       abort "command failed: #{env.inspect} #{cmd.join(' ')}"
     end
   end