Writing your own recipes

Writing recipes

• The recipe API

  • install

    • __init__

      handout

      The initializer is responsible for computing a part's options. After the initializer call, the options directory must reflect the full configuration of the part. In particular, if a recipe reads any data from other sections, it must be reflected in the options. The options data after the initializer is called is used to determine if a configuration has changed when deciding if a part has to be reinstalled. When a part is reinstalled, it is uninstalled and then installed.

    • install

      handout

      The install method installs the part. It is used when a part is added to a buildout, or when a part is reinstalled.

      The install recipe must return a sequence of paths that that should be removed when the part is uninstalled. Most recipes just create files or directories and removing these is sufficient for uninstalling the part.

    • update

      handout

      The update method is used when a part is already installed and it's configuration hasn't changed from previous buildouts. It can return None or a sequence of paths. If paths are returned, they are added to the set of installed paths.

  • uninstall

    handout

    Most recipes simply create files or directories and the built-in buildout uninstall support is sufficient. If a recipe does more than simply create files, then an uninstall recipe will likely be needed.

Install Recipes

mkdirrecipe.py:

import logging, os, zc.buildout

class Mkdir:

    def __init__(self, buildout, name, options):
        self.name, self.options = name, options
        options['path'] = os.path.join(
                              buildout['buildout']['directory'],
                              options['path'],
                              )
        if not os.path.isdir(os.path.dirname(options['path'])):
            logging.getLogger(self.name).error(
                'Cannot create %s. %s is not a directory.',
                options['path'], os.path.dirname(options['path']))
            raise zc.buildout.UserError('Invalid Path')

mkdirrecipe.py continued

def install(self):
    path = self.options['path']
    logging.getLogger(self.name).info(
        'Creating directory %s', os.path.basename(path))
    os.mkdir(path)
    return path

def update(self):
    pass

Uninstall recipes

servicerecipe.py:

import os

class Service:

    def __init__(self, buildout, name, options):
        self.options = options

    def install(self):
        os.system("chkconfig --add %s" % self.options['script'])
        return ()

    def update(self):
        pass

def uninstall_service(name, options):
    os.system("chkconfig --del %s" % options['script'])

Buildout entry points

setup.py:

from setuptools import setup

entry_points = """
[zc.buildout]
mkdir = mkdirrecipe:Mkdir
service = servicerecipe:Service
default = mkdirrecipe:Mkdir

[zc.buildout.uninstall]
service = servicerecipe:uninstall_service
"""

setup(name='recipes', entry_points=entry_points)