Install and configure controller node in OpenStack Installation Guide import error at /usr/lib/python2.6/site-packages/migrate/versioning/schema.py", line 10

[Jeff Silverman]

-----------------------------------
Built: 2014-07-23T07:06:38 00:00
git SHA: 7352529ae6cd61366c2295601eb795ba3444acb6
URL: http://docs.openstack.org/trunk/install-guide/install/apt/content/nova-controller-install.html
source File: file:/home/jenkins/workspace/openstack-manuals-tox-doc-publishdocs/doc/install-guide/section_nova-controller-install.xml
xml:id: nova-controller-install

I am running under Centos 6.5

When I run su -s /bin/sh -c "nova-manage db sync" nova

I get an exception at
File "/usr/lib/python2.6/site-packages/migrate/versioning/schema.py", line 10, in <module>
    from sqlalchemy import exceptions as sa_exceptions
ImportError: cannot import name exceptions
Uncaught exception. Entering post mortem debugging

The complete stack trace in the debugger is

(Pdb) c
Command failed, please check log for more info
Traceback (most recent call last):
  File "/usr/lib64/python2.6/pdb.py", line 1296, in main
    pdb._runscript(mainpyfile)
  File "/usr/lib64/python2.6/pdb.py", line 1215, in _runscript
    self.run(statement)
  File "/usr/lib64/python2.6/bdb.py", line 372, in run
    exec cmd in globals, locals
  File "<string>", line 1, in <module>
  File "/usr/bin/nova-manage", line 10, in <module>
    sys.exit(main())
  File "/usr/lib/python2.6/site-packages/nova/cmd/manage.py", line 1374, in main
    ret = fn(*fn_args, **fn_kwargs)
  File "/usr/lib/python2.6/site-packages/nova/cmd/manage.py", line 883, in sync
    return migration.db_sync(version)
  File "/usr/lib/python2.6/site-packages/nova/db/migration.py", line 29, in db_sync
    return IMPL.db_sync(version=version)
  File "/usr/lib/python2.6/site-packages/nova/utils.py", line 427, in __getattr__
    backend = self.__get_backend()
  File "/usr/lib/python2.6/site-packages/nova/utils.py", line 423, in __get_backend
    self.__backend = __import__(name, None, None, fromlist)
  File "/usr/lib/python2.6/site-packages/nova/db/sqlalchemy/migration.py", line 20, in <module>
    from migrate.versioning import api as versioning_api
  File "/usr/lib/python2.6/site-packages/migrate/versioning/api.py", line 32, in <module>
    from migrate.versioning import (exceptions, repository, schema, version,
  File "/usr/lib/python2.6/site-packages/migrate/versioning/schema.py", line 10, in <module>
    from sqlalchemy import exceptions as sa_exceptions
ImportError: cannot import name exceptions
Uncaught exception. Entering post mortem debugging
Running 'cont' or 'step' will restart the program
> /usr/lib/python2.6/site-packages/migrate/versioning/schema.py(10)<module>()
-> from sqlalchemy import exceptions as sa_exceptions
(Pdb)

Here is the PYTHONPATH at the point of the failure
(Pdb) print sys.path
['/usr/bin', '/usr/lib64/python26.zip', '/usr/lib64/python2.6', '/usr/lib64/python2.6/plat-linux2', '/usr/lib64/python2.6/lib-tk', '/usr/lib64/python2.6/lib-old', '/usr/lib64/python2.6/lib-dynload', '/usr/lib64/python2.6/site-packages', '/usr/lib64/python2.6/site-packages/PIL', '/usr/lib64/python2.6/site-packages/gtk-2.0', '/usr/lib/python2.6/site-packages', '/usr/lib/python2.6/site-packages/setuptools-0.6c11-py2.6.egg-info']
(Pdb)

sqlalchemy is installed:
<email address hidden>:~# yum list | fgrep -i sqlal
Repository sl-release-el6 is listed more than once in the configuration
python-sqlalchemy.x86_64 0.8.4-1.el6 @openstack-icehouse
python-sqlalchemy0.7.x86_64 0.7.8-1.el6 @epel-6-x86_64
python-flask-sqlalchemy.noarch 0.16-2.el6 epel-6-x86_64
python-sqlalchemy-debuginfo.x86_64 0.8.4-1.el6 openstack-icehouse
python-sqlalchemy0.8.x86_64 0.8.2-4.el6 epel-6-x86_64
python-zope-sqlalchemy.noarch 0.4-3.el6 centos-6.5-base
<email address hidden>:~#

This was previously reported on <email address hidden> which I now think was the wrong place to put it.

Jeff

[Jeff Silverman (jeffsilverm)]

I think the problem is there is a file missing from sqlalchemy.

I used the sys.path variable to see where the imported file might be from. I settled on /usr/lib64/python2.6/site-packages/
I looked to see what packages supply a file that's present

<email address hidden>:~# yum provides /usr/lib64/python2.6/site-packages/sqlalchemy/events.py
Loaded plugins: fastestmirror, priorities, security
Repository sl-release-el6 is listed more than once in the configuration
Loading mirror speeds from cached hostfile
 * epel: mirror.pnl.gov
14039 packages excluded due to repository priority protections
centos-6.5-plus/filelists | 978 kB 00:00
centos-6.5-updates/filelists | 2.8 MB 00:00
epel/filelists_db | 8.9 MB 00:01
epel-6-x86_64/filelists | 7.3 MB 00:00
foreman-plugins/filelists_db | 45 kB 00:00
openstack-icehouse/filelists_db | 1.9 MB 00:00
puppetlabs-deps/filelists_db | 189 kB 00:00
puppetlabs-products/filelists_db | 954 kB 00:00
sl-release-el6/filelists | 815 kB 00:00
python-sqlalchemy-0.8.4-1.el6.x86_64 : Modular and flexible ORM library for python
Repo : openstack-icehouse
Matched from:
Filename : /usr/lib64/python2.6/site-packages/sqlalchemy/events.py

python-sqlalchemy-0.8.4-1.el6.x86_64 : Modular and flexible ORM library for python
Repo : installed
Matched from:
Other : Provides-match: /usr/lib64/python2.6/site-packages/sqlalchemy/events.py

Then looked more information from python-sqlalchemy:

<email address hidden>:~# yum info python-sqlalchemy
Loaded plugins: fastestmirror, priorities, security
Repository sl-release-el6 is listed more than once in the configuration
Loading mirror speeds from cached hostfile
 * epel: mirrors.cat.pdx.edu
14039 packages excluded due to repository priority protections
Installed Packages
Name : python-sqlalchemy
Arch : x86_64
Version : 0.8.4
Release : 1.el6
Size : 18 M
Repo : installed
From repo : openstack-icehouse
Summary : Modular and flexible ORM library for python
URL : http://www.sqlalchemy.org/
License : MIT
Description : SQLAlchemy is an Object Relational Mappper (ORM) that provides a flexible,
            : high-level interface to SQL databases. Database and domain concepts are
            : decoupled, allowing both sides maximum flexibility and power. SQLAlchemy...

[Jeff Silverman (jeffsilverm)]

I found the answer, I think, at https://github.com/FormAlchemy/pyramid_formalchemy/issues/27 . Somebody changed the name of the file /usr/lib64/python2.6/site-packages/sqlalchemy/exceptions.py to /usr/lib64/python2.6/site-packages/sqlalchemy/exc.py. So I created a symlink: ln -s exc.py exceptions.py and tried the program again. That solves one problem but creates a new problem:

2014-07-23 11:20:18.757 29987 CRITICAL nova [-] AttributeError: 'module' object has no attribute 'DatabaseNotControlledError'

[Andreas Jaeger (jaegerandi)]

I don't see any documentation related issue here.