From d9a128a375cc448cc0a5de7930f0cf1fb6d47f1a Mon Sep 17 00:00:00 2001
From: Hanjie Wang <48261337+hwang381@users.noreply.github.com>
Date: Wed, 8 Jan 2020 11:33:39 -0800
Subject: [PATCH] In Vagrant post-processor, check whether the host system is
 able to create a dummy Vagrant box before processing (#8431)

---
 post-processor/vagrant/post-processor.go |  5 ++++
 post-processor/vagrant/util.go           | 34 ++++++++++++++++++++++++
 2 files changed, 39 insertions(+)

diff --git a/post-processor/vagrant/post-processor.go b/post-processor/vagrant/post-processor.go
index 0e57829f2..004365d27 100644
--- a/post-processor/vagrant/post-processor.go
+++ b/post-processor/vagrant/post-processor.go
@@ -93,6 +93,11 @@ func (p *PostProcessor) PostProcessProvider(name string, provider Provider, ui p
 		config = specificConfig
 	}
 
+	err := CreateDummyBox(ui, config.CompressionLevel)
+	if err != nil {
+		return nil, false, err
+	}
+
 	ui.Say(fmt.Sprintf("Creating Vagrant box for '%s' provider", name))
 
 	config.ctx.Data = &outputPathTemplate{
diff --git a/post-processor/vagrant/util.go b/post-processor/vagrant/util.go
index 55c89ae5c..476136122 100644
--- a/post-processor/vagrant/util.go
+++ b/post-processor/vagrant/util.go
@@ -5,6 +5,7 @@ import (
 	"compress/flate"
 	"encoding/json"
 	"fmt"
+	"github.com/hashicorp/packer/packer/tmp"
 	"io"
 	"log"
 	"os"
@@ -158,6 +159,39 @@ func DirToBox(dst, dir string, ui packer.Ui, level int) error {
 	return filepath.Walk(dir, tarWalk)
 }
 
+// CreateDummyBox create a dummy Vagrant-compatible box under temporary dir
+// This function is mainly used to check cases such as the host system having
+// a GNU tar incompatible uname that will cause the actual Vagrant box creation
+// to fail later
+func CreateDummyBox(ui packer.Ui, level int) error {
+	ui.Say("Creating a dummy Vagrant box to ensure the host system can create one correctly")
+
+	// Create a temporary dir to create dummy Vagrant box from
+	tempDir, err := tmp.Dir("packer")
+	if err != nil {
+		return err
+	}
+	defer os.RemoveAll(tempDir)
+
+	// Write some dummy metadata for the box
+	if err := WriteMetadata(tempDir, make(map[string]string)); err != nil {
+		return err
+	}
+
+	// Create the dummy Vagrant box
+	tempBox, err := tmp.File("box-*.box")
+	if err != nil {
+		return err
+	}
+	defer tempBox.Close()
+	defer os.Remove(tempBox.Name())
+	if err := DirToBox(tempBox.Name(), tempDir, nil, level); err != nil {
+		return err
+	}
+
+	return nil
+}
+
 // WriteMetadata writes the "metadata.json" file for a Vagrant box.
 func WriteMetadata(dir string, contents interface{}) error {
 	if _, err := os.Stat(filepath.Join(dir, "metadata.json")); os.IsNotExist(err) {