@@ -36,6 +36,7 @@ import (

 	"github.com/docker/docker/pkg/namesgenerator"

 	"github.com/docker/docker/pkg/parsers"

 	"github.com/docker/docker/pkg/parsers/kernel"

+	"github.com/docker/docker/pkg/pidfile"

 	"github.com/docker/docker/pkg/resolvconf"

 	"github.com/docker/docker/pkg/stringid"

 	"github.com/docker/docker/pkg/sysinfo"

@@ -836,12 +837,13 @@ func NewDaemonFromDirectory(config *Config, eng *engine.Engine) (*Daemon, error)

 	// Claim the pidfile first, to avoid any and all unexpected race conditions.

 	// Some of the init doesn't need a pidfile lock - but let's not try to be smart.

 	if config.Pidfile != "" {

-		if err := utils.CreatePidFile(config.Pidfile); err != nil {

+		file, err := pidfile.New(config.Pidfile)

+		if err != nil {

 			return nil, err

 		}

 		eng.OnShutdown(func() {

 			// Always release the pidfile last, just in case

-			utils.RemovePidFile(config.Pidfile)

+			file.Remove()

 		})

 	}

new file mode 100644

@@ -0,0 +1,44 @@

+package pidfile

+

+import (

+	"fmt"

+	"io/ioutil"

+	"log"

+	"os"

+	"path/filepath"

+	"strconv"

+)

+

+type PidFile struct {

+	path string

+}

+

+func checkPidFileAlreadyExists(path string) error {

+	if pidString, err := ioutil.ReadFile(path); err == nil {

+		if pid, err := strconv.Atoi(string(pidString)); err == nil {

+			if _, err := os.Stat(filepath.Join("/proc", string(pid))); err == nil {

+				return fmt.Errorf("pid file found, ensure docker is not running or delete %s", path)

+			}

+		}

+	}

+	return nil

+}

+

+func New(path string) (file *PidFile, err error) {

+	if err := checkPidFileAlreadyExists(path); err != nil {

+		return nil, err

+	}

+

+	file = &PidFile{path: path}

+	err = ioutil.WriteFile(path, []byte(fmt.Sprintf("%d", os.Getpid())), 0644)

+

+	return file, err

+}

+

+func (file PidFile) Remove() error {

+	if err := os.Remove(file.path); err != nil {

+		log.Printf("Error removing %s: %s", file.path, err)

+		return err

+	}

+	return nil

+}

new file mode 100644

@@ -0,0 +1,32 @@

+package pidfile

+

+import (

+	"io/ioutil"

+	"os"

+	"path/filepath"

+	"testing"

+)

+

+func TestNewAndRemove(t *testing.T) {

+	dir, err := ioutil.TempDir(os.TempDir(), "test-pidfile")

+	if err != nil {

+		t.Fatal("Could not create test directory")

+	}

+

+	file, err := New(filepath.Join(dir, "testfile"))

+	if err != nil {

+		t.Fatal("Could not create test file", err)

+	}

+

+	if err := file.Remove(); err != nil {

+		t.Fatal("Could not delete created test file")

+	}

+}

+

+func TestRemoveInvalidPath(t *testing.T) {

+	file := PidFile{path: filepath.Join("foo", "bar")}

+

+	if err := file.Remove(); err == nil {

+		t.Fatal("Non-existing file doesn't give an error on delete")

+	}

+}

deleted file mode 100644

@@ -1,36 +0,0 @@

-package utils

-

-import (

-	"fmt"

-	"io/ioutil"

-	"log"

-	"os"

-	"strconv"

-)

-

-func CreatePidFile(pidfile string) error {

-	if pidString, err := ioutil.ReadFile(pidfile); err == nil {

-		pid, err := strconv.Atoi(string(pidString))

-		if err == nil {

-			if _, err := os.Stat(fmt.Sprintf("/proc/%d/", pid)); err == nil {

-				return fmt.Errorf("pid file found, ensure docker is not running or delete %s", pidfile)

-			}

-		}

-	}

-

-	file, err := os.Create(pidfile)

-	if err != nil {

-		return err

-	}

-

-	defer file.Close()

-

-	_, err = fmt.Fprintf(file, "%d", os.Getpid())

-	return err

-}

-

-func RemovePidFile(pidfile string) {

-	if err := os.Remove(pidfile); err != nil {

-		log.Printf("Error removing %s: %s", pidfile, err)

-	}

-}