Merge pull request #1683 from vikaschoudhary16/runc-systemd-race

Fix race against systemd

Author: hqhq

libcontainer/cgroups/systemd/apply_systemd.go

@@ -295,10 +295,13 @@ func (m *Manager) Apply(pid int) error {
 		}
 	}
 
-	if _, err := theConn.StartTransientUnit(unitName, "replace", properties, nil); err != nil && !isUnitExists(err) {
+	statusChan := make(chan string)
+	if _, err := theConn.StartTransientUnit(unitName, "replace", properties, statusChan); err != nil && !isUnitExists(err) {
 		return err
 	}
 
+	<-statusChan
+
 	if err := joinCgroups(c, pid); err != nil {
 		return err
 	}