Update server dependencies

Godeps/_workspace/src/github.com/mitchellh/go-homedir/homedir.go

@@ -7,20 +7,49 @@ import (
 	"os/exec"
 	"path/filepath"
 	"runtime"
+	"strconv"
 	"strings"
+	"sync"
 )
 
+// DisableCache will disable caching of the home directory. Caching is enabled
+// by default.
+var DisableCache bool
+
+var homedirCache string
+var cacheLock sync.RWMutex
+
 // Dir returns the home directory for the executing user.
 //
 // This uses an OS-specific method for discovering the home directory.
 // An error is returned if a home directory cannot be detected.
 func Dir() (string, error) {
-	if runtime.GOOS == "windows" {
-		return dirWindows()
+	if !DisableCache {
+		cacheLock.RLock()
+		cached := homedirCache
+		cacheLock.RUnlock()
+		if cached != "" {
+			return cached, nil
+		}
 	}
 
-	// Unix-like system, so just assume Unix
-	return dirUnix()
+	cacheLock.Lock()
+	defer cacheLock.Unlock()
+
+	var result string
+	var err error
+	if runtime.GOOS == "windows" {
+		result, err = dirWindows()
+	} else {
+		// Unix-like system, so just assume Unix
+		result, err = dirUnix()
+	}
+
+	if err != nil {
+		return "", err
+	}
+	homedirCache = result
+	return result, nil
 }
 
 // Expand expands the path to include the home directory if the path
@@ -53,9 +82,28 @@ func dirUnix() (string, error) {
 		return home, nil
 	}
 
-	// If that fails, try the shell
+	// If that fails, try getent
 	var stdout bytes.Buffer
-	cmd := exec.Command("sh", "-c", "eval echo ~$USER")
+	cmd := exec.Command("getent", "passwd", strconv.Itoa(os.Getuid()))
+	cmd.Stdout = &stdout
+	if err := cmd.Run(); err != nil {
+		// If "getent" is missing, ignore it
+		if err != exec.ErrNotFound {
+			return "", err
+		}
+	} else {
+		if passwd := strings.TrimSpace(stdout.String()); passwd != "" {
+			// username:password:uid:gid:gecos:home:shell
+			passwdParts := strings.SplitN(passwd, ":", 7)
+			if len(passwdParts) > 5 {
+				return passwdParts[5], nil
+			}
+		}
+	}
+
+	// If all else fails, try the shell
+	stdout.Reset()
+	cmd = exec.Command("sh", "-c", "cd && pwd")
 	cmd.Stdout = &stdout
 	if err := cmd.Run(); err != nil {
 		return "", err