From 4115068f8b50b694094adf8e68cd0da7a9ca5eb3 Mon Sep 17 00:00:00 2001
From: Devananda van der Veen <devananda.vdv@gmail.com>
Date: Thu, 17 Jan 2013 13:30:58 -0800
Subject: [PATCH] Baremetal/utils should not log certain exceptions

unlink_without_raise was logging exceptions when it failed to unlink a
file, which is confusing since it is often called on non-existing files.

create_link_without_raise was also logging exceptions when it failed
to create a symlink.

This patch corrects this behaviour; both functions now explicitly check
for the type of error they expect, and then suppress that. If another
type of OSError is encountered, a warning is logged. This patch also
adds unit tests for both functions.

fixes bug 1097931.

Change-Id: Ie36f59dce34a6c67765770c5f968c003003acc88
---
 nova/tests/baremetal/test_utils.py | 36 ++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/nova/tests/baremetal/test_utils.py b/nova/tests/baremetal/test_utils.py
index 827b1fca..2615a26c 100644
--- a/nova/tests/baremetal/test_utils.py
+++ b/nova/tests/baremetal/test_utils.py
@@ -20,6 +20,9 @@
 
 import mox
 
+import errno
+import os
+
 from nova import exception
 from nova import test
 from nova.virt.baremetal import utils
@@ -32,3 +35,36 @@ class BareMetalUtilsTestCase(test.TestCase):
         self.assertEqual(len(s), 10)
         s = utils.random_alnum(100)
         self.assertEqual(len(s), 100)
+
+    def test_unlink(self):
+        self.mox.StubOutWithMock(os, "unlink")
+        os.unlink("/fake/path")
+
+        self.mox.ReplayAll()
+        utils.unlink_without_raise("/fake/path")
+        self.mox.VerifyAll()
+
+    def test_unlink_ENOENT(self):
+        self.mox.StubOutWithMock(os, "unlink")
+        os.unlink("/fake/path").AndRaise(OSError(errno.ENOENT))
+
+        self.mox.ReplayAll()
+        utils.unlink_without_raise("/fake/path")
+        self.mox.VerifyAll()
+
+    def test_create_link(self):
+        self.mox.StubOutWithMock(os, "symlink")
+        os.symlink("/fake/source", "/fake/link")
+
+        self.mox.ReplayAll()
+        utils.create_link_without_raise("/fake/source", "/fake/link")
+        self.mox.VerifyAll()
+
+    def test_create_link_EEXIST(self):
+        self.mox.StubOutWithMock(os, "symlink")
+        os.symlink("/fake/source", "/fake/link").AndRaise(
+                OSError(errno.EEXIST))
+
+        self.mox.ReplayAll()
+        utils.create_link_without_raise("/fake/source", "/fake/link")
+        self.mox.VerifyAll()