Separate commands into other directories

command/build/command.go

+package build
+
+import "fmt"
+import "github.com/mitchellh/packer/packer"
+
+type Command byte
+
+func (Command) Run(env *packer.Environment, arg []string) int {
+	fmt.Println("HI!")
+	return 0
+}
+
+func (Command) Synopsis() string {
+	return "build image(s) from tempate"
+}

packer.go

@@ -3,12 +3,16 @@ package main
 
 import (
 	"github.com/mitchellh/packer/packer"
+	"github.com/mitchellh/packer/command/build"
 	"fmt"
 	"os"
 )
 
 func main() {
-	env, err := packer.NewEnvironment(packer.DefaultEnvironmentConfig())
+	envConfig := packer.DefaultEnvironmentConfig()
+	envConfig.Command["build"] = new(build.Command)
+
+	env, err := packer.NewEnvironment(envConfig)
 	if err != nil {
 		fmt.Fprintf(os.Stderr, "Packer initialization error: \n\n%s\n", err)
 		os.Exit(1)

packer/environment.go

@@ -34,6 +34,7 @@ type EnvironmentConfig struct {
 func DefaultEnvironmentConfig() *EnvironmentConfig {
 	config := &EnvironmentConfig{}
 	config.BuilderFactory = new(NilBuilderFactory)
+	config.Command = make(map[string]Command)
 	config.Ui = &ReaderWriterUi{os.Stdin, os.Stdout}
 	return config
 }

packer/environment_test.go

@@ -40,6 +40,13 @@ func testEnvironment() *Environment {
 	return env
 }
 
+func TestEnvironment_DefaultConfig_Command(t *testing.T) {
+	assert := asserts.NewTestingAsserts(t, true)
+
+	config := DefaultEnvironmentConfig()
+	assert.NotNil(config.Command, "default Command should not be nil")
+}
+
 func TestEnvironment_DefaultConfig_Ui(t *testing.T) {
 	assert := asserts.NewTestingAsserts(t, true)