Set drbd usermode helper on config upgrade

Signed-off-by: Luca Bigliardi <shammash@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>

lib/constants.py

@@ -441,6 +441,7 @@ IP6_ADDRESS_ANY = "::"
 TCP_PING_TIMEOUT = 10
 GANETI_RUNAS = "root"
 DEFAULT_VG = "xenvg"
+DEFAULT_DRBD_HELPER = "/bin/true"
 MIN_VG_SIZE = 20480
 DEFAULT_MAC_PREFIX = "aa:00:00"
 LVM_STRIPECOUNT = _autoconf.LVM_STRIPECOUNT

lib/objects.py

@@ -364,6 +364,12 @@ class ConfigData(ConfigObject):
       node.UpgradeConfig()
     for instance in self.instances.values():
       instance.UpgradeConfig()
+    if self.cluster.drbd_usermode_helper is None:
+      # To decide if we set an helper let's check if at least one instance has
+      # a DRBD disk. This does not cover all the possible scenarios but it
+      # gives a good approximation.
+      if self.HasAnyDiskOfType(constants.LD_DRBD8):
+        self.cluster.drbd_usermode_helper = constants.DEFAULT_DRBD_HELPER
 
 
 class NIC(ConfigObject):