Entries For: December 2007

2007-12-10

Zope 3 dependencies in Zope 2 buildout

Filed Under:

plone
zope-3

Describe a buildout recipe to avoid fetching zope 3 libraries when installing eggs with zope 3 depedencies in a zope 2 buildout

I got tired removing zope.interface, zope.component, zope.deferredimport, zope.event, ... of my eggs folder inside my buildout when installing package such as z3c.sqlalchemy in my Zope2 / Plone buildouts ...

After the discussion on Zope3-users list and thanks to Jim lights, I wrote a really simple recipe which just create egg links to zope libraries in your develop-eggs so that setuptools can see that the dependencies are already satisfied.

So if you list your zope library :

$ ls yourbuildout/parts/yourzope2/lib/python/zope

app configuration documenttemplate exceptions i18n __init__.py pagetemplate schema structuredtext testbrowser viewlet
cachedescriptors contentprovider dottedname formlib i18nmessageid interface proxy security tal testing
component deprecation event hookable index modulealias publisher server tales thread

You will get

$ ls yourbuildout/develop-eggs

zope.app.component.egg-info zope.app.security.egg-info zope.dottedname.egg-info zope.interface.egg-info zope.structuredtext.egg-info
zope.app.egg-info zope.app.testing.egg-info zope.event.egg-info zope.modulealias.egg-info zope.tal.egg-info
zope.app.event.egg-info zope.cachedescriptors.egg-info zope.exceptions.egg-info zope.pagetemplate.egg-info zope.tales.egg-info
zope.app.i18n.egg-info zope.component.egg-info zope.formlib.egg-info zope.proxy.egg-info zope.testbrowser.egg-info
zope.app.interface.egg-info zope.configuration.egg-info zope.hookable.egg-info zope.publisher.egg-info zope.testing.egg-info
zope.app.pagetemplate.egg-info zope.contentprovider.egg-info zope.i18n.egg-info zope.schema.egg-info zope.thread.egg-info
zope.app.publisher.egg-info zope.deprecation.egg-info zope.i18nmessageid.egg-info zope.security.egg-info zope.viewlet.egg-info
zope.app.schema.egg-info zope.documenttemplate.egg-info zope.index.egg-info zope.server.egg-info

Where each of these file will be seen for setuptools as an egg:

$ cat yourbuildout/develop-eggs/zope.app.component.egg-info

Metadata-Version: 1.0
Name: zope.app.component
Version: 0.0

Sure this might look like an ugly hook but I can't wait for zope 2 eggification

2007-12-06

Buildout and Virtualenv

Filed Under:

plone
zope-3

How and why use buildout with virtualenv

Buildout is this wonderful tool which helps you to automate setup and configuration of your applications.

Virtualenv is a tool which will help you to isolate your python environment

A few days ago I got stuck during a long time because I didn't see that one library I installed in my global site-packages of my favourite python 2.4 (on my ubuntu: /usr/lib/python2.4/site-packages/) was a lower version of a library I was using in my buildout. Package was sqlalchemy 0.4 in my global sites-package and my buildout based application was using sqlalchemy 0.3.8 ... Here is a simple solution to avoid this kind of things.

Idea is to start buildout with a python free of any external library. Virtualenv is the answer.

Install Virtualenv

Easy:

$ easy_install virtualenv

you will have then a file that you can run: /usr/bin/virtualenv

Let's say you have a buildout configuration go into it:

$ cd myApp.buildout
$ ls -l
bootstrap.py
buildout.cfg

Now you just have to create the python environment without any access to the global site-packages with virtualenv:

$ virtualenv --no-site-packages .
You will have then your new python in the bin folder :

$ ls -l bin
activate
easy_install
easy_install-2.4
python2.4

You can now run the buildout configuration with your new python:

$ ./bin/python2.4 bootstrap.py
$ ./bin/buildout
This will create you a nice and totally isolated environment ...