When developing zope/plone eggs with buildout I have to edit the buildout configuration file ( in 3 places ) every time I create/delete/rename a development egg in the src directory or in other development directories (sometime I have more than one).


I have to add/delete/rename the egg in the eggs option of the [buildout] and then add/delete/rename the egg path in the develop option of the [buildout] and in the end add/delete/rename the zcml option of the zope [instance] or in the configure.zcml file of my policy package. This is too much specially when the speed is set to development mode. I need a less boring way to develop.


Solution


buildout.eggtractor is a buildout extension that scans the src directory or a list of directories I give for eggs and picks them up automatically. So no more editing of the buildout's configuration file.


When buildout.eggtractor finds an egg in the scanned directory it:


  • adds the egg to the eggs option of all zope instance parts or to a set of given parts

  • adds the egg's path in the develop option of the [buildout]

  • If tractor-autoload-zcml is not set to false, scans the egg folder for configure.zcml, meta.zcml and overrides.zcml and adds the appropriate zcml entries to the zcml option of the zope instance parts or to a set of given parts.


This steps are done on the fly when running buildout. So I can add/delete/rename an egg and it will be picked up.


NOTE: The extension does not write to the buildout's configuration file.


buildout.eggtractor options


tractor-src-directory: A set of directories to scan for development eggs. Defaults to the src directory of the buildout.

tractor-target-parts: A set of parts to update their eggs option with eggs found in the tractor-src-directory. Defaults to zope instance parts if any.

tractor-autoload-zcml(boolean): Update the zcml option of tractor-target-parts with the eggs found in tractor-src-directory. Defaults to true

tractor-zcml-top: A set of eggs to load their zcml files first. Defaults to an empty set.

How to use it


Using buildout.eggtractor is very simple. As said, it is a buildout extension. All I have to do is to declare it in the extensions option:


  [buildout]

  parts =

  

  extensions = buildout.eggtractor

That's all. buildout.eggtractor will scan the src directory and do its job every time I run the buildout command.


When I have other directories I want to scan I just add an tractor-src-directory option in the [buildout] and add my directories there:


  [buildout]

  parts =

  

  extensions = buildout.eggtractor

  

  tractor-src-directory = 

                        dev-src1 

                        dev-src2

                        src

In a few cases when the priority of loading zcml files matters. I add the egg to be loaded first in the tractor-zcml-top option in the [buildout]:


  [buildout]

  parts =

  

  extensions = buildout.eggtractor

  

  tractor-src-directory = 

            dev-src1 

            dev-src2

            src

            

  tractor-zcml-top = 

            plone.app.mypackage1

If I want to add the eggs found in the development directories to the eggs option of a given set of parts, I add a tractor-target-parts option and add the parts there:


  [buildout]

  parts = instance1 instance2 instance3

  

  extensions = buildout.eggtractor

  

  tractor-target-parts = instance1 instance3

This way only instance1 and instance3 will be updated.


If I have already other way to include the zcml files (ie: z3c.autoinclude) and don't want eggtractor to generate the zcml slugs, I add an tractor-autoload-zcml option and set it to false


In most cases you will only need to add buildout.eggtractor to the extensions option of the [buildout] without any extra configuration options.

LIMITATION


The extension assumes that the egg name reflects its file system structure example: if the egg name is com.mustap.www the extension assumes that the file system structure is one of the following::

  • com.mustap.www/src/com/mustap/www

  • com.mustap.www/com/mustap/www


This is where the extension looks for configure.zcml, meta.zcml and overrides.zcml files.


If the egg name does not reflect the file system structure, the extension will ignore it.

XXX: I guess walking through the directory is better than this assumption.
In my case this is not a limitation as I choose my egg names that way.

URL

You can get it from http://pypi.python.org/pypi/buildout.eggtractor

THANKS

Martin, Wichert and Hanno for the help and feedbacks