Use node UUIDs for executing LU hooks

LUNodeAdd, the only LU using a node name still, is changed to overwrite
PreparePostHookNodes() and use node UUIDs only as well.
This allows to remove the support for 3-tuples as results of
BuildHooksNodes() and removes the translation to node names.

Fixes issue 742.
Signed-off-by: Thomas Thrainer <thomasth@google.com>
Reviewed-by: Michele Tartara <mtartara@google.com>

lib/cmdlib/base.py

@@ -269,13 +269,10 @@ class LogicalUnit(object):
   def BuildHooksNodes(self):
     """Build list of nodes to run LU's hooks.
 
-    @rtype: tuple; (list, list) or (list, list, list)
+    @rtype: tuple; (list, list)
     @return: Tuple containing a list of node UUIDs on which the hook
       should run before the execution and a list of node UUIDs on which the
-      hook should run after the execution. As it might be possible that the
-      node UUID is not known at the time this method is invoked, an optional
-      third list can be added which contains node names on which the hook
-      should run after the execution (in case of node add, for instance).
+      hook should run after the execution.
       No nodes should be returned as an empty list (and not None).
     @note: If the C{HPATH} attribute of the LU class is C{None}, this function
       will not be called.

lib/cmdlib/node.py

@@ -138,7 +138,10 @@ class LUNodeAdd(LogicalUnit):
       hook_nodes = list(set(hook_nodes) - set([new_node_info.uuid]))
 
     # add the new node as post hook node by name; it does not have an UUID yet
-    return (hook_nodes, hook_nodes, [self.op.node_name, ])
+    return (hook_nodes, hook_nodes)
+
+  def PreparePostHookNodes(self, post_hook_node_uuids):
+    return post_hook_node_uuids + [self.new_node.uuid]
 
   def CheckPrereq(self):
     """Check prerequisites.

lib/hooksmaster.py

@@ -268,15 +268,10 @@ class HooksMaster(object):
       nodes = (None, None)
     else:
       hooks_nodes = lu.BuildHooksNodes()
-      to_name = lambda node_uuids: frozenset(lu.cfg.GetNodeNames(node_uuids))
-      if len(hooks_nodes) == 2:
-        nodes = (to_name(hooks_nodes[0]), to_name(hooks_nodes[1]))
-      elif len(hooks_nodes) == 3:
-        nodes = (to_name(hooks_nodes[0]),
-                 to_name(hooks_nodes[1]) | frozenset(hooks_nodes[2]))
-      else:
+      if len(hooks_nodes) != 2:
         raise errors.ProgrammerError(
-          "LogicalUnit.BuildHooksNodes must return a 2- or 3-tuple")
+          "LogicalUnit.BuildHooksNodes must return a 2-tuple")
+      nodes = (frozenset(hooks_nodes[0]), frozenset(hooks_nodes[1]))
 
     master_name = cluster_name = None
     if lu.cfg:

test/py/cmdlib/cluster_unittest.py

@@ -234,7 +234,7 @@ class TestLUClusterPostInit(CmdlibTestCase):
 
     self.ExecOpCode(op)
 
-    self.assertSingleHooksCall([self.master.name],
+    self.assertSingleHooksCall([self.master.uuid],
                                "cluster-init",
                                constants.HOOKS_PHASE_POST)
 

test/py/ganeti.hooks_unittest.py

@@ -495,7 +495,7 @@ class TestHooksRunnerEnv(unittest.TestCase):
     assert isinstance(self.lu, FakeNoHooksLU), "LU was replaced"
 
 
-class FakeEnvWithNodeNameLU(cmdlib.LogicalUnit):
+class FakeEnvWithCustomPostHookNodesLU(cmdlib.LogicalUnit):
   HPATH = "env_test_lu"
   HTYPE = constants.HTYPE_GROUP
 
@@ -506,7 +506,10 @@ class FakeEnvWithNodeNameLU(cmdlib.LogicalUnit):
     return {}
 
   def BuildHooksNodes(self):
-    return (["a"], ["a"], ["explicit.node1.com", "explicit.node2.com"])
+    return (["a"], ["a"])
+
+  def PreparePostHookNodes(self, post_hook_node_uuids):
+    return post_hook_node_uuids + ["b"]
 
 
 class TestHooksRunnerEnv(unittest.TestCase):
@@ -514,7 +517,8 @@ class TestHooksRunnerEnv(unittest.TestCase):
     self._rpcs = []
 
     self.op = opcodes.OpTestDummy(result=False, messages=[], fail=False)
-    self.lu = FakeEnvWithNodeNameLU(FakeProc(), self.op, FakeContext(), None)
+    self.lu = FakeEnvWithCustomPostHookNodesLU(FakeProc(), self.op,
+                                               FakeContext(), None)
 
   def _HooksRpc(self, *args):
     self._rpcs.append(args)
@@ -526,15 +530,13 @@ class TestHooksRunnerEnv(unittest.TestCase):
     hm.RunPhase(constants.HOOKS_PHASE_PRE)
 
     (node_list, hpath, phase, env) = self._rpcs.pop(0)
-    self.assertEqual(node_list, set(["node_a.example.com"]))
+    self.assertEqual(node_list, set(["a"]))
 
     # Check post-phase hook
     hm.RunPhase(constants.HOOKS_PHASE_POST)
 
     (node_list, hpath, phase, env) = self._rpcs.pop(0)
-    self.assertEqual(node_list, set(["node_a.example.com",
-                                     "explicit.node1.com",
-                                     "explicit.node2.com"]))
+    self.assertEqual(node_list, set(["a", "b"]))
 
     self.assertRaises(IndexError, self._rpcs.pop)