packer: Make builder type available in configs [GH-154]

packer/build.go

@@ -11,6 +11,11 @@ const (
 	// build.
 	BuildNameConfigKey = "packer_build_name"
 
+	// This is the key in the configuration that is set to the type
+	// of the builder that is run. This is useful for provisioners and
+	// such who want to make use of this.
+	BuilderTypeConfigKey = "packer_builder_type"
+
 	// This is the key in configurations that is set to "true" when Packer
 	// debugging is enabled.
 	DebugConfigKey = "packer_debug"
@@ -110,6 +115,7 @@ func (b *coreBuild) Prepare() (err error) {
 
 	packerConfig := map[string]interface{}{
 		BuildNameConfigKey:   b.name,
+		BuilderTypeConfigKey: b.builderType,
 		DebugConfigKey:       b.debug,
 		ForceConfigKey:       b.force,
 	}

packer/build_test.go

@@ -11,6 +11,7 @@ func testBuild() *coreBuild {
 		name:          "test",
 		builder:       &TestBuilder{artifactId: "b"},
 		builderConfig: 42,
+		builderType:   "foo",
 		hooks: map[string][]Hook{
 			"foo": []Hook{&TestHook{}},
 		},
@@ -41,6 +42,7 @@ func TestBuild_Prepare(t *testing.T) {
 
 	packerConfig := map[string]interface{}{
 		BuildNameConfigKey:   "test",
+		BuilderTypeConfigKey: "foo",
 		DebugConfigKey:       false,
 		ForceConfigKey:       false,
 	}
@@ -88,6 +90,7 @@ func TestBuild_Prepare_Debug(t *testing.T) {
 
 	packerConfig := map[string]interface{}{
 		BuildNameConfigKey:   "test",
+		BuilderTypeConfigKey: "foo",
 		DebugConfigKey:       true,
 		ForceConfigKey:       false,
 	}

packer/template_test.go

@@ -2,8 +2,8 @@ package packer
 
 import (
 	"cgl.tideland.biz/asserts"
-	"sort"
 	"reflect"
+	"sort"
 	"testing"
 )