From e4c29dc5798f04f15d898e98197c079fd43799fe Mon Sep 17 00:00:00 2001
From: Ryan Uber <ru@ryanuber.com>
Date: Fri, 11 Sep 2015 20:32:55 -0700
Subject: [PATCH] client: alloc dirs tolerate missing directories

---
 client/client.go    |  2 +-
 client/util.go      |  3 +++
 client/util_test.go | 17 ++++++++++++++---
 3 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/client/client.go b/client/client.go
index 5a3323f8c..5b445e028 100644
--- a/client/client.go
+++ b/client/client.go
@@ -243,7 +243,7 @@ func (c *Client) restoreState() error {
 
 	// Scan the directory
 	list, err := ioutil.ReadDir(filepath.Join(c.config.StateDir, "alloc"))
-	if err != nil {
+	if err != nil && !os.IsNotExist(err) {
 		return fmt.Errorf("failed to list alloc state: %v", err)
 	}
 
diff --git a/client/util.go b/client/util.go
index 032e8d502..4efec9e18 100644
--- a/client/util.go
+++ b/client/util.go
@@ -106,6 +106,9 @@ func persistState(path string, data interface{}) error {
 func restoreState(path string, data interface{}) error {
 	buf, err := ioutil.ReadFile(path)
 	if err != nil {
+		if os.IsNotExist(err) {
+			return nil
+		}
 		return fmt.Errorf("failed to read state: %v", err)
 	}
 	if err := json.Unmarshal(buf, data); err != nil {
diff --git a/client/util_test.go b/client/util_test.go
index 904749db6..d6c165b9b 100644
--- a/client/util_test.go
+++ b/client/util_test.go
@@ -1,7 +1,9 @@
 package client
 
 import (
+	"io/ioutil"
 	"os"
+	"path/filepath"
 	"reflect"
 	"testing"
 	"time"
@@ -80,6 +82,16 @@ func TestShuffleStrings(t *testing.T) {
 }
 
 func TestPersistRestoreState(t *testing.T) {
+	dir, err := ioutil.TempDir("", "nomad")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	defer os.RemoveAll(dir)
+
+	// Use a state path inside a non-existent directory. This
+	// verifies that the directory is created properly.
+	statePath := filepath.Join(dir, "subdir", "test-persist")
+
 	type stateTest struct {
 		Foo int
 		Bar string
@@ -90,15 +102,14 @@ func TestPersistRestoreState(t *testing.T) {
 		Bar: "the quick brown fox",
 		Baz: true,
 	}
-	defer os.Remove("test-persist")
 
-	err := persistState("test-persist", &state)
+	err = persistState(statePath, &state)
 	if err != nil {
 		t.Fatalf("err: %v", err)
 	}
 
 	var out stateTest
-	err = restoreState("test-persist", &out)
+	err = restoreState(statePath, &out)
 	if err != nil {
 		t.Fatalf("err: %v", err)
 	}