Implement gnt-node evacuate

This patch adds a new 'evacuate' subcommand to gnt-node. The command
will do a replace disks for all instances having that node as secondary
with the new target being the new node given.

The syntax is:
  gnt-node evacuate src_node target_node

The command by itself doesn't do any resource checks, and instead relies
on the LUFailoverInstance code to do that.

Reviewed-by: imsnah

diff --git a/lib/constants.py b/lib/constants.py
index 9516d4d..1590cb7 100644 (file)
--- a/lib/constants.py
+++ b/lib/constants.py
@@ -91,8 +91,10 @@ INISECT_EXP = "export"
 INISECT_INS = "instance"
 
 # common exit codes
+EXIT_SUCCESS = 0
 EXIT_NOTMASTER = 11
 EXIT_NODESETUP_ERROR = 12
+EXIT_CONFIRMATION = 13 # need user confirmation
 
 # tags
 TAG_CLUSTER = "cluster"

diff --git a/man/gnt-node.sgml b/man/gnt-node.sgml
index 3bf31fd..a5e2615 100644 (file)
--- a/man/gnt-node.sgml
+++ b/man/gnt-node.sgml
@@ -126,6 +126,31 @@
     </refsect2>
 
     <refsect2>
+      <title>EVACUATE</title>
+
+      <cmdsynopsis>
+        <command>evacuate</command>
+        <arg>-f</arg>
+        <arg choice="req"><replaceable>source_node</replaceable></arg>
+        <arg choice="req"><replaceable>destination_node</replaceable></arg>
+      </cmdsynopsis>
+
+      <para>
+        This command will change the secondary node from the source
+        node to the destination node for all instances having the
+        source node as secondary. It works only for instances having
+        a remote raid disk layout.
+      </para>
+
+      <para>
+        Example:
+        <screen>
+          # gnt-node evacuate node1.example.com node2.example.com
+        </screen>
+      </para>
+    </refsect2>
+
+    <refsect2>
       <title>FAILOVER</title>
 
       <cmdsynopsis>

diff --git a/scripts/gnt-node b/scripts/gnt-node
index 8d4cfcb..391f25e 100755 (executable)
--- a/scripts/gnt-node
+++ b/scripts/gnt-node
@@ -94,6 +94,65 @@ def ListNodes(opts, args):
   return 0
 
 
+def EvacuateNode(opts, args):
+  """Relocate all secondary instance from a node.
+
+  """
+  force = opts.force
+  selected_fields = ["name", "sinst_list"]
+  src_node, dst_node = args
+
+  op = opcodes.OpQueryNodes(output_fields=selected_fields, names=[src_node])
+  result = SubmitOpCode(op)
+  src_node, sinst = result[0]
+  op = opcodes.OpQueryNodes(output_fields=["name"], names=[dst_node])
+  result = SubmitOpCode(op)
+  dst_node = result[0][0]
+
+  if src_node == dst_node:
+    raise errors.OpPrereqError("Evacuate node needs different source and"
+                               " target nodes (node %s given twice)" %
+                               src_node)
+
+  if not sinst:
+    logger.ToStderr("No secondary instances on node %s, exiting." % src_node)
+    return constants.EXIT_SUCCESS
+
+  sinst = utils.NiceSort(sinst)
+
+  retcode = constants.EXIT_SUCCESS
+
+  if not force and not AskUser("Relocate instance(s) %s from node\n"
+                               " %s to node\n %s?" %
+                               (",".join("'%s'" % name for name in sinst),
+                               src_node, dst_node)):
+    return constants.EXIT_CONFIRMATION
+
+  good_cnt = bad_cnt = 0
+  for iname in sinst:
+    op = opcodes.OpReplaceDisks(instance_name=iname,
+                                remote_node=dst_node)
+    try:
+      logger.ToStdout("Replacing disks for instance %s" % iname)
+      SubmitOpCode(op)
+      logger.ToStdout("Instance %s has been relocated" % iname)
+      good_cnt += 1
+    except errors.GenericError, err:
+      nret, msg = FormatError(err)
+      retcode |= nret
+      logger.ToStderr("Error replacing disks for instance %s: %s" %
+                      (iname, msg))
+      bad_cnt += 1
+
+  if retcode == constants.EXIT_SUCCESS:
+    logger.ToStdout("All %d instance(s) relocated successfully." % good_cnt)
+  else:
+    logger.ToStdout("There were errors during the relocation:\n"
+                    "%d error(s) out of %d instance(s)." %
+                    (bad_cnt, good_cnt + bad_cnt))
+  return retcode
+
+
 def FailoverNode(opts, args):
   """Failover all primary instance on a node.
 
@@ -220,6 +279,11 @@ commands = {
                        help="Specify the secondary ip for the node",
                        metavar="ADDRESS", default=None),],
           "<node_name>", "Add a node to the cluster"),
+  'evacuate': (EvacuateNode, ARGS_FIXED(2),
+               [DEBUG_OPT, FORCE_OPT],
+               "[-f] <src_node> <dst_node>",
+               "Relocate the secondary instances from the first node"
+               " to the second one (only for instances of type remote_raid1)"),
   'failover': (FailoverNode, ARGS_ONE,
                [DEBUG_OPT, FORCE_OPT,
                 make_option("--ignore-consistency", dest="ignore_consistency",