From f177de89834b05df353b13ec4a310d74cb821a67 Mon Sep 17 00:00:00 2001
From: Jonathan Boulle <jonathanboulle@gmail.com>
Date: Wed, 27 May 2015 09:52:55 -0700
Subject: [PATCH] util: add IsRunningSystemd (similar to sd_booted)

---
 util/util.go | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)
 create mode 100644 util/util.go

diff --git a/util/util.go b/util/util.go
new file mode 100644
index 00000000..33832a1e
--- /dev/null
+++ b/util/util.go
@@ -0,0 +1,33 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package util contains utility functions related to systemd that applications
+// can use to check things like whether systemd is running.
+package util
+
+import (
+	"os"
+)
+
+// IsRunningSystemd checks whether the host was booted with systemd as its init
+// system. This functions similar to systemd's `sd_booted(3)`: internally, it
+// checks whether /run/systemd/system/ exists and is a directory.
+// http://www.freedesktop.org/software/systemd/man/sd_booted.html
+func IsRunningSystemd() bool {
+	fi, err := os.Lstat("/run/systemd/system")
+	if err != nil {
+		return false
+	}
+	return fi.IsDir()
+}