From 4de494505f95b7313a8d5b34ecac286db66698f9 Mon Sep 17 00:00:00 2001
From: Arnaud Lemaire <alemaire@norad.fr>
Date: Fri, 31 Jul 2015 17:35:43 +0200
Subject: [PATCH] do not run build.sh if no build runlevel

---
 builder/cnt.go |  3 +++
 utils/files.go | 19 +++++++++++++++++++
 2 files changed, 22 insertions(+)
 create mode 100644 utils/files.go

diff --git a/builder/cnt.go b/builder/cnt.go
index e8fd3b1b..ab888aa8 100644
--- a/builder/cnt.go
+++ b/builder/cnt.go
@@ -204,6 +204,9 @@ func (cnt *Cnt) Build() error {
 }
 
 func (cnt *Cnt) runBuild() {
+	if res, err := utils.IsDirEmpty(cnt.target + "/runlevels/build"); res || err != nil {
+		return
+	}
 	if err := utils.ExecCmd("systemd-nspawn", "--version"); err == nil {
 		log.Get().Info("Run with systemd-nspawn")
 		if err := utils.ExecCmd("systemd-nspawn", "--directory=" + cnt.rootfs, "--capability=all",
diff --git a/utils/files.go b/utils/files.go
new file mode 100644
index 00000000..5b59f84d
--- /dev/null
+++ b/utils/files.go
@@ -0,0 +1,19 @@
+package utils
+import (
+	"os"
+	"io"
+)
+
+func IsDirEmpty(name string) (bool, error) {
+	f, err := os.Open(name)
+	if err != nil {
+		return false, err
+	}
+	defer f.Close()
+
+	_, err = f.Readdir(1)
+	if err == io.EOF {
+		return true, nil
+	}
+	return false, err // Either not empty or error, suits both cases
+}
\ No newline at end of file