New image cache breaks Glance on Windows

[Jay Pipes]

The requirement of python-xattr means that Glance is no longer working on Windows, since python-xattr is a *nix-only library.

We have two solutions:

* Make the image cache extensible -- have xattr driver support on *nix and use, say, a SQLite DB on Windows
* Make the image cache fully an extension and make Glance packages that do not include the image cache extension (and thus the the xattr dependency)

[Peter Pouliot (ppouliot)]

We successfully reproduced this. This currently breaks installation on windows completely.

ErrorThe following errors were encountered: Error: Launchpad system error var LP = { cache: {}, links: {} }; var cookie_scope = '; Path=/; Secure; Domain=.launchpad.net'; // Define a global YUI sandbox that should be used by everyone. var LPS = YUI({ // Don't try to fetch CSS files. fetchCSS: false, // For paranoia, set a low timeout to not wait on loading a resource. timeout: 50 }); LPS.use('node', 'event-delegate', 'lp', 'lp.app.links', 'lp.app.longpoll', function(Y) { Y.on('load', function(e) { sortables_init(); initInlineHelp(); Y.lp.activate_collapsibles(); activateFoldables(); activateConstrainBugExpiration(); Y.lp.app.links.check_valid_lp_links(); // Longpolling will only start if // LP.cache.longpoll is populated. Y.lp.app.longpoll.setupLongPollManager(); }, window); // Hook up the function that dismisses the help window if we click // anywhere outside of it. Y.on('click', handleClickOnPage, window); Y.on('lp:context:web_link:changed', function(e) { window.location = e.new_value; }); }); var _gaq = _gaq || []; _gaq.push(['_setAccount', 'UA-12833497-1']); _gaq.push(['_setDomainName', '.launchpad.net']); _gaq.push(['_setAllowHash', false]); _gaq.push(['_trackPageview']); (function() { var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true; ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js'; (document.getElementsByTagName('head')[0] || document.getElementsByTagName('body')[0]).appendChild(ga); })(); Ale

[Alex Landman (alandman)]

I am attaching the nova-compute log we are getting on a HyperV host.

[Alex Landman (alandman)]

The display of the dependency causing nova to fail.

[Jordan Rinke (jordanrinke)]

You can work around this by changing the following... (note: these changes break glance registry/api but won't hurt the client needed for hyperv) - note this isn't the best way to do it, it is just the way I did it really quick when I saw it broke my install.

24: import xattr
to
24: # import xattr

213: entry_xattr = xattr.xattr(path)
to
213: entry_xattr = path # was xattr.xattr(path)

229: entry_xattr = xattr.xattr(path)
to
229: entry_xattr = path # was xattr.xattr(path)

[Jay Pipes (jaypipes)]

Setting to medium Priority, as doing non-standard fstab modifications to enable user_xattr support should not be a requirement to run Glance API servers...

[Openstack Gerrit (openstack-gerrit)]

Reviewed: https://review.openstack.org/1064
Committed: http://github.com/openstack/glance/commit/39c855743423175beca6955ed30c15b9c40f9129
Submitter: Jenkins
Branch: master

 status fixcommitted
 done

commit 39c855743423175beca6955ed30c15b9c40f9129
Author: Jay Pipes <email address hidden>
Date: Fri Oct 21 16:10:32 2011 -0400

    Adds Driver Layer to Image Cache

    Fixes LP Bug#879136 - keyerror: 'image' when doing nova image-list
    Fixes LP Bug#819936 - New image cache breaks Glance on Windows

    This patch refactors the image cache further by adding an
    adaptable driver layer to the cache. The existing filesystem-based
    driver that depended on python-xattr and conditional fstab support
    has been moved to /glance/image_cache/drivers/xattr.py, and a new
    default driver is now based on SQLite and has no special requirements.

    The image cache now contains a simple interface for pruning the
    cache. Instead of the logic being contained in
    /glance/image_cache/pruner.py, now the prune logic is self-contained
    within the ImageCache.prune() method, with pruning calling the
    simple well-defined driver methods of get_least_recently_accessed()
    and get_cache_size().

    Adds a functional test case for the caching middleware and adds
    documentation on how to configure the image cache drivers.

    TODO: cache-manage middleware...
    TODO: cache management docs

    Change-Id: Id7ae73549d6bb39222eb7ac0427b0083fd1af3ec