Add hello-world executable

.gitignore

@@ -11,3 +11,5 @@ tags
 .bundle/
 custom_hooks
 hooks/*.d
+/go_build
+/bin/hello-world

README.md

@@ -66,9 +66,12 @@ make
 sudo make install
 ```
+To install gitlab-shell you also need a Go compiler version 1.5 or newer. https://golang.org/dl/
+
 ## Setup
     ./bin/install
+    ./bin/compile
 ## Check

bin/compile

+#!/usr/bin/env ruby
+
+require 'fileutils'
+
+# This will set the ROOT_PATH variable
+require_relative '../lib/gitlab_init'
+
+GO_DIR = 'go'
+GOPATH = File.join(ROOT_PATH, 'go_build')
+GO_PACKAGE = File.join('gitlab.com/gitlab-org/gitlab-shell', GO_DIR)
+
+def main
+  FileUtils.rm_rf(GOPATH)
+  build_source_dir = File.join(GOPATH, 'src', GO_PACKAGE)
+  FileUtils.mkdir_p(build_source_dir)
+  FileUtils.cp_r(File.join(ROOT_PATH, GO_DIR, '.'), build_source_dir)
+  env = {
+    'GOPATH' => GOPATH,
+    'GO15VENDOREXPERIMENT' => '1',
+  }
+  run!(env, %W[go install #{GO_PACKAGE}/cmd/...])
+  executables = Dir[File.join(GOPATH, 'bin', '*')]
+  FileUtils.chmod(0755, executables)
+  FileUtils.cp(executables, File.join(ROOT_PATH, 'bin'))
+end
+
+def run!(env, cmd)
+  raise "env must be a hash" unless env.is_a?(Hash)
+  raise "cmd must be an array" unless cmd.is_a?(Array)
+
+  if !system(env, *cmd)
+    abort "command failed: #{env.inspect} #{cmd.join(' ')}"
+  end
+end
+
+main

go/README.md

+# Go executables for gitlab-shell
+
+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`.

go/cmd/hello-world/main.go

+package main
+
+import "fmt"
+
+func main() {
+	fmt.Println("Hello, world!")
+}