From 632186c1a4e3d971bab1d017ea3289e92c85d86c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?P=C3=A1draig=20Brady?= <P@draigBrady.com>
Date: Wed, 24 Oct 2012 13:44:37 +0100
Subject: [PATCH] Use updated parallel install versions of epel package

Use sqlalchemy >= 0.6.3 WebOb >= 1.0 Routes >= 1.12.3 PasteDeploy >= 1.5.0
and depend on the parallel installable
versions of these packages to satisfy those requirements.

Delve into pkg_resources a little to get it to modify sys.path,
so that our parallel installed egg takes precedence over the
system default module versions.
(cherry picked from commit 7b25747ffc21d0771e864f57ab2088725c8851f0)

Conflicts:
	bin/cinder-manage
---
 bin/cinder-manage                 |  7 ++++---
 cinder/__init__.py                | 30 ++++++++++++++++++++++++++++++
 cinder/db/sqlalchemy/migration.py |  7 ++++++-
 3 files changed, 40 insertions(+), 4 deletions(-)

diff --git a/bin/cinder-manage b/bin/cinder-manage
index de7955d..364944a 100755
--- a/bin/cinder-manage
+++ b/bin/cinder-manage
@@ -59,9 +59,6 @@ import os
 import sys
 import uuid
 
-from sqlalchemy import create_engine, MetaData, Table
-from sqlalchemy.ext.declarative import declarative_base
-from sqlalchemy.orm import sessionmaker
 
 
 # If ../cinder/__init__.py exists, add ../ to Python search path, so that
@@ -87,6 +84,10 @@ from cinder.openstack.common import uuidutils
 from cinder import utils
 from cinder import version
 
+from sqlalchemy import create_engine, MetaData, Table
+from sqlalchemy.orm import sessionmaker
+from sqlalchemy.ext.declarative import declarative_base
+
 FLAGS = flags.FLAGS
 
 
diff --git a/cinder/__init__.py b/cinder/__init__.py
index f8db8e8..1b4ac39 100644
--- a/cinder/__init__.py
+++ b/cinder/__init__.py
@@ -31,6 +31,36 @@
 .. moduleauthor:: Andy Smith <andy@anarkystic.com>
 """
 
+import sys
+import pkg_resources
+
+# If there is a conflicting non egg module,
+# i.e. an older standard system module installed,
+# then replace it with this requirement
+def replace_dist(requirement):
+    try:
+        return pkg_resources.require(requirement)
+    except pkg_resources.VersionConflict:
+        e = sys.exc_info()[1]
+        dist=e.args[0]
+        req=e.args[1]
+        if dist.key == req.key and not dist.location.endswith('.egg'):
+            del pkg_resources.working_set.by_key[dist.key]
+            # We assume there is no need to adjust sys.path
+            # and the associated pkg_resources.working_set.entries
+            return pkg_resources.require(requirement)
+
+replace_dist("WebOb >= 1.0")
+replace_dist("SQLAlchemy >= 0.6.3")
+replace_dist("Routes >= 1.12.3")
+
+replace_dist("PasteDeploy >= 1.5.0")
+# This hack is needed because replace_dist() results in
+# the standard paste module path being at the start of __path__.
+# TODO: See can we get pkg_resources to do the right thing directly
+import paste
+paste.__path__.insert(0, paste.__path__.pop(-1))
+
 import gettext
 
 
diff --git a/cinder/db/sqlalchemy/migration.py b/cinder/db/sqlalchemy/migration.py
index 5365d9c..e2fcd83 100644
--- a/cinder/db/sqlalchemy/migration.py
+++ b/cinder/db/sqlalchemy/migration.py
@@ -57,7 +57,12 @@ if (not hasattr(migrate, '__version__') or
 
 
 # NOTE(jkoelker) Delay importing migrate until we are patched
-from migrate import exceptions as versioning_exceptions
+try:
+    # Try the more specific path first (migrate <= 0.6)
+    from migrate.versioning import exceptions as versioning_exceptions
+except ImportError:
+    # Use the newer path (migrate >= 0.7)
+    from migrate import exceptions as versioning_exceptions
 from migrate.versioning import api as versioning_api
 from migrate.versioning.repository import Repository