From 185d2765befb908467153c3e0ab1a282c07e975e Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <mitchell.hashimoto@gmail.com>
Date: Fri, 10 May 2013 13:01:54 -0700
Subject: [PATCH] command/build: Run the builds in parallel

---
 builder/amazonebs/builder.go |  6 +++++-
 command/build/command.go     | 18 ++++++++++++++++++
 2 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/builder/amazonebs/builder.go b/builder/amazonebs/builder.go
index c89d906a8..c0ca44868 100644
--- a/builder/amazonebs/builder.go
+++ b/builder/amazonebs/builder.go
@@ -38,7 +38,11 @@ func (b *Builder) Prepare(raw interface{}) (err error) {
 	}
 
 	log.Printf("Config: %+v\n", b.config)
+
+	// TODO: Validate the configuration
 	return
 }
 
-func (*Builder) Run(packer.Build, packer.Ui) {}
+func (*Builder) Run(b packer.Build, ui packer.Ui) {
+	ui.Say("Building an AWS image...\n")
+}
diff --git a/command/build/command.go b/command/build/command.go
index 19ab76e2b..85dcfe399 100644
--- a/command/build/command.go
+++ b/command/build/command.go
@@ -4,6 +4,7 @@ import (
 	"github.com/mitchellh/packer/packer"
 	"io/ioutil"
 	"log"
+	"sync"
 )
 
 type Command byte
@@ -54,6 +55,23 @@ func (Command) Run(env packer.Environment, args []string) int {
 		}
 	}
 
+	// Run all the builds in parallel and wait for them to complete
+	var wg sync.WaitGroup
+	for _, b := range builds {
+		log.Printf("Starting build run: %s\n", b.Name())
+
+		// Increment the waitgroup so we wait for this item to finish properly
+		wg.Add(1)
+
+		// Run the build in a goroutine
+		go func() {
+			defer wg.Done()
+			b.Run(env.Ui())
+		}()
+	}
+
+	wg.Wait()
+
 	env.Ui().Say("YAY!\n")
 	return 0
 }