builder/amazon/instance: default x509_upload_path

builder/amazon/instance/builder.go

@@ -81,6 +81,10 @@ func (b *Builder) Prepare(raws ...interface{}) error {
 			"--batch"
 	}
 
+	if b.config.X509UploadPath == "" {
+		b.config.X509UploadPath = "/tmp"
+	}
+
 	// Accumulate any errors
 	errs := common.CheckUnusedConfig(md)
 	errs = packer.MultiErrorAppend(errs, b.config.AccessConfig.Prepare()...)
@@ -121,10 +125,6 @@ func (b *Builder) Prepare(raws ...interface{}) error {
 			errs, fmt.Errorf("x509_key_path points to bad file: %s", err))
 	}
 
-	if b.config.X509UploadPath == "" {
-		errs = packer.MultiErrorAppend(errs, errors.New("x509_upload_path is required"))
-	}
-
 	if errs != nil && len(errs.Errors) > 0 {
 		return errs
 	}

builder/amazon/instance/builder_test.go

@@ -213,7 +213,7 @@ func TestBuilderPrepare_X509UploadPath(t *testing.T) {
 
 	config["x509_upload_path"] = ""
 	err := b.Prepare(config)
-	if err == nil {
-		t.Fatal("should have error")
+	if err != nil {
+		t.Fatalf("should not have error: %s", err)
 	}
 }