From 207774131724caaf0849450a19fbb207cf5655f4 Mon Sep 17 00:00:00 2001
From: Iustin Pop <iustin@google.com>
Date: Fri, 19 Jun 2009 14:09:19 +0200
Subject: [PATCH] LU execution: implement dry-run framework
This patch adds a new (global) opcode flag 'dry_run' which, when True,
causes early exit from the LU workflow, returning a special value from
the LU object (initialized in the parent LogicalUnit class, and which if
not overriden from child LUs will be None).
Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>
---
lib/cmdlib.py | 5 +++++
lib/mcpu.py | 9 +++++++++
lib/opcodes.py | 6 ++++--
3 files changed, 18 insertions(+), 2 deletions(-)
diff --git a/lib/cmdlib.py b/lib/cmdlib.py
index bda05fab9..de16fcc7c 100644
--- a/lib/cmdlib.py
+++ b/lib/cmdlib.py
@@ -56,6 +56,9 @@ class LogicalUnit(object):
Note that all commands require root permissions.
+ @ivar dry_run_result: the value (if any) that will be returned to the caller
+ in dry-run mode (signalled by opcode dry_run parameter)
+
"""
HPATH = None
HTYPE = None
@@ -86,6 +89,8 @@ class LogicalUnit(object):
# logging
self.LogWarning = processor.LogWarning
self.LogInfo = processor.LogInfo
+ # support for dry-run
+ self.dry_run_result = None
for attr_name in self._OP_REQP:
attr_val = getattr(op, attr_name, None)
diff --git a/lib/mcpu.py b/lib/mcpu.py
index 11fa7434f..0844b7409 100644
--- a/lib/mcpu.py
+++ b/lib/mcpu.py
@@ -113,6 +113,15 @@ class Processor(object):
h_results = hm.RunPhase(constants.HOOKS_PHASE_PRE)
lu.HooksCallBack(constants.HOOKS_PHASE_PRE, h_results,
self._feedback_fn, None)
+
+ if getattr(lu.op, "dry_run", False):
+ # in this mode, no post-hooks are run, and the config is not
+ # written (as it might have been modified by another LU, and we
+ # shouldn't do writeout on behalf of other threads
+ self.LogInfo("dry-run mode requested, not actually executing"
+ " the operation")
+ return lu.dry_run_result
+
try:
result = lu.Exec(self._feedback_fn)
h_results = hm.RunPhase(constants.HOOKS_PHASE_POST)
diff --git a/lib/opcodes.py b/lib/opcodes.py
index 541bbc0f5..4de40ba4e 100644
--- a/lib/opcodes.py
+++ b/lib/opcodes.py
@@ -103,11 +103,13 @@ class OpCode(BaseOpCode):
from this class should override OP_ID.
@cvar OP_ID: The ID of this opcode. This should be unique amongst all
- childre of this class.
+ children of this class.
+ @ivar dry_run: Whether the LU should be run in dry-run mode, i.e. just
+ the check steps
"""
OP_ID = "OP_ABSTRACT"
- __slots__ = BaseOpCode.__slots__ + []
+ __slots__ = BaseOpCode.__slots__ + ["dry_run"]
def __getstate__(self):
"""Specialized getstate for opcodes.
--
GitLab