From 9ef50487fb98c2cd07bd3dcf9b738a9e8a9bd277 Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <mitchell.hashimoto@gmail.com>
Date: Sat, 26 Apr 2014 20:33:12 -0700
Subject: [PATCH] core: Create cache directory only when needed [GH-367]

---
 CHANGELOG.md    | 1 +
 packer.go       | 5 -----
 packer/cache.go | 9 +++++++++
 3 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index e9131b4d2..d1fb43056 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -34,6 +34,7 @@ BUG FIXES:
 
   * core: Errors are properly shown when adding bad floppy files. [GH-1043]
   * core: Fix some URL parsing issues on Windows.
+  * core: Create Cache directory only when it is needed. [GH-367]
   * builder/amazon-instance: Use S3Endpoint for ec2-upload-bundle arg,
       which works for every region. [GH-904]
   * builder/digitalocean: updated default image_id [GH-1032]
diff --git a/packer.go b/packer.go
index d645df45e..0674e503b 100644
--- a/packer.go
+++ b/packer.go
@@ -106,11 +106,6 @@ func wrappedMain() int {
 		return 1
 	}
 
-	if err := os.MkdirAll(cacheDir, 0755); err != nil {
-		fmt.Fprintf(os.Stderr, "Error preparing cache directory: \n\n%s\n", err)
-		return 1
-	}
-
 	log.Printf("Setting cache directory: %s", cacheDir)
 	cache := &packer.FileCache{CacheDir: cacheDir}
 
diff --git a/packer/cache.go b/packer/cache.go
index a9bd4a62b..d65b5b806 100644
--- a/packer/cache.go
+++ b/packer/cache.go
@@ -3,6 +3,8 @@ package packer
 import (
 	"crypto/sha256"
 	"encoding/hex"
+	"log"
+	"os"
 	"path/filepath"
 	"strings"
 	"sync"
@@ -84,6 +86,13 @@ func (f *FileCache) cachePath(key string, hashKey string) string {
 		}
 	}
 
+	// Make the cache directory. We ignore errors here, but
+	// log them in case something happens.
+	if err := os.MkdirAll(f.CacheDir, 0755); err != nil {
+		log.Printf(
+			"[ERR] Error making cacheDir: %s %s", f.CacheDir, err)
+	}
+
 	return filepath.Join(f.CacheDir, hashKey+suffix)
 }