command/build: Run the builds in parallel

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")
+}

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
 }