ConfigWriter: handle the drained node flag

This patch changes the master candidate pool computations in
ConfigWriter to properly handle drained nodes. They are now excluded
from counting towards the reachable number of candidates.

The patch also adds verification of consistency for the node status.

Reviewed-by: imsnah

diff --git a/lib/config.py b/lib/config.py
index d7a1e9f..a6f3d69 100644 (file)
--- a/lib/config.py
+++ b/lib/config.py
@@ -304,6 +304,14 @@ class ConfigWriter:
       result.append("Not enough master candidates: actual %d, target %d" %
                     (mc_now, mc_max))
 
+    # node checks
+    for node in data.nodes.values():
+      if [node.master_candidate, node.drained, node.offline].count(True) > 1:
+        result.append("Node %s state is invalid: master_candidate=%s,"
+                      " drain=%s, offline=%s" %
+                      (node.name, node.master_candidate, node.drain,
+                       node.offline))
+
     # drbd minors check
     d_map, duplicates = self._UnlockedComputeDRBDMap()
     for node, minor, instance_a, instance_b in duplicates:
@@ -903,7 +911,7 @@ class ConfigWriter:
     """
     mc_now = mc_max = 0
     for node in self._config_data.nodes.itervalues():
-      if not node.offline:
+      if not (node.offline or node.drained):
         mc_max += 1
       if node.master_candidate:
         mc_now += 1
@@ -939,7 +947,7 @@ class ConfigWriter:
         if mc_now >= mc_max:
           break
         node = self._config_data.nodes[name]
-        if node.master_candidate or node.offline:
+        if node.master_candidate or node.offline or node.drained:
           continue
         mod_list.append(node)
         node.master_candidate = True