Commit a9026cec authored by amos's avatar amos

Added uninstall recipes feature.


git-svn-id: http://svn.zope.org/repos/main/zc.buildout/trunk@71422 62d5b8a3-27da-0310-9561-8e5933582275
parent 62e77f82
......@@ -20,6 +20,15 @@ priorities include:
Change History
**************
Unreleased version
==================
Feature Changes
---------------
- Added uninstall recipes for dealing with complex uninstallation
scenarios.
1.0.0b13 (2006-12-04)
=====================
......
......@@ -248,6 +248,20 @@ class Buildout(UserDict.DictMixin):
# ununstall part
self._logger.info('Uninstalling %s', part)
# run uinstall recipe
recipe = installed_part_options[part].get('uninstall')
if recipe:
if ':' in recipe:
recipe, entry = recipe.split(':')
else:
entry = 'default'
self._logger.info('Running uninstall recipe')
uninstaller = pkg_resources.load_entry_point(
recipe, 'zc.buildout.uninstall', entry)
uninstaller(part, installed_part_options[part])
# remove created files and directories
self._uninstall(
installed_part_options[part]['__buildout_installed__'])
installed_parts = [p for p in installed_parts if p != part]
......
......@@ -197,7 +197,8 @@ installed. If the part is uninstalled or reinstalled, then the path
returned will be removed by the buildout machinery. A recipe install
method is expected to return a string, or an iterable of strings
containing paths to be removed if a part is uninstalled. For most
recipes, this is all of the uninstall support needed.
recipes, this is all of the uninstall support needed. For more complex
uninstallation scenarios use `Uninstall recipes`_.
The update method is responsible for updating an already installed
part. An empty method is often provided, as in this example, if parts
......@@ -795,6 +796,238 @@ set the logging level to WARNING
op3 b2 3
recipe recipes:debug
Uninstall recipes
-----------------
As we've seen, when parts are installed, buildout keeps track of files
and directories that they create. When the parts are uninstalled these
files and directories are deleted.
Sometimes more clean up is needed. For example, a recipe might add a
system service by calling chkconfig --add during installation. Later
during uninstallation, chkconfig --del will need to be called to
remove the system service.
In order to deal with these uninstallation issues, you can register
uninstall recipes. Uninstall recipes are registered using the
'zc.buildout.uninstall' entry point. Parts specify uninstall recipes
using the 'uninstall' option.
In comparison to regular recipes, uninstall recipes are much
simpler. They are simply callable objects that accept the name of the
part to be uninstalled and the part's options dictionary. Uninstall
recipes don't have access to the part itself since it maybe not be
able to be instantiated at uninstallation time.
Here's a recipe that simulates installation of a system service, along
with an uninstall recipe that simulates removing the service.
>>> write(sample_buildout, 'recipes', 'service.py',
... """
... class Service:
...
... def __init__(self, buildout, name, options):
... self.buildout = buildout
... self.name = name
... self.options = options
...
... def install(self):
... print "chkconfig --add %s" % self.options['script']
... return ()
...
... def update(self):
... pass
...
...
... def uninstall_service(name, options):
... print "chkconfig --del %s" % options['script']
... """)
To use these recipes we must register them using entry points.
>>> write(sample_buildout, 'recipes', 'setup.py',
... """
... from setuptools import setup
... entry_points = (
... '''
... [zc.buildout]
... mkdir = mkdir:Mkdir
... debug = debug:Debug
... service = service:Service
...
... [zc.buildout.uninstall]
... uninstall_service = service:uninstall_service
... ''')
... setup(name="recipes", entry_points=entry_points)
... """)
Here's how these recipes could be used in a buildout:
>>> write(sample_buildout, 'buildout.cfg',
... """
... [buildout]
... develop = recipes
... parts = service
...
... [service]
... recipe = recipes:service
... script = /path/to/script
... uninstall = recipes:uninstall_service
... """)
When the buildout is run the service will be installed
>>> print system(buildout)
buildout: Develop: /sample-buildout/recipes
buildout: Uninstalling debug
buildout: Installing service
chkconfig --add /path/to/script
<BLANKLINE>
The service has been installed. If the buildout is run again with no changes, the serivce shouldn't be changed.
>>> print system(buildout)
buildout: Develop: /sample-buildout/recipes
buildout: Updating service
<BLANKLINE>
Now we change the service part to trigger uninstallation and
re-installation.
>>> write(sample_buildout, 'buildout.cfg',
... """
... [buildout]
... develop = recipes
... parts = service
...
... [service]
... recipe = recipes:service
... script = /path/to/a/different/script
... uninstall = recipes:uninstall_service
... """)
>>> print system(buildout)
buildout: Develop: /sample-buildout/recipes
buildout: Uninstalling service
buildout: Running uninstall recipe
chkconfig --del /path/to/script
buildout: Installing service
chkconfig --add /path/to/a/different/script
<BLANKLINE>
Now we remove the service part, and add another part.
>>> write(sample_buildout, 'buildout.cfg',
... """
... [buildout]
... develop = recipes
... parts = debug
...
... [debug]
... recipe = recipes:debug
... """)
>>> print system(buildout)
buildout: Develop: /sample-buildout/recipes
buildout: Uninstalling service
buildout: Running uninstall recipe
chkconfig --del /path/to/a/different/script
buildout: Installing debug
recipe recipes:debug
<BLANKLINE>
Uninstall recipes don't have to take care of removing all the files
and directories created by the part. This is still done automatically,
following the execution of the uninstall recipe. An upshot is that an
uninstallation recipe can access files and directories created by a
recipe before they are deleted.
For example, here's an uninstallation recipe that simulates backing up
a directory.
>>> write(sample_buildout, 'recipes', 'backup.py',
... """
... import os
... def backup_directory(name, options):
... path = options['path']
... size = os.stat(path).st_size
... print "backing up directory %s of size %s" % (path, size)
... """)
It must be registered with the zc.buildout.uninstall entry point.
>>> write(sample_buildout, 'recipes', 'setup.py',
... """
... from setuptools import setup
... entry_points = (
... '''
... [zc.buildout]
... mkdir = mkdir:Mkdir
... debug = debug:Debug
... service = service:Service
...
... [zc.buildout.uninstall]
... uninstall_service = service:uninstall_service
... backup = backup:backup_directory
... ''')
... setup(name="recipes", entry_points=entry_points)
... """)
Now we can use it with a part. It's necessary to pick a part that
defines a 'path' option, since that's what the uninstall recipe
expects.
>>> write(sample_buildout, 'buildout.cfg',
... """
... [buildout]
... develop = recipes
... parts = dir debug
...
... [dir]
... recipe = recipes:mkdir
... uninstall = recipes:backup
... path = my_directory
...
... [debug]
... recipe = recipes:debug
... """)
Run the buildout to install the part.
>>> print system(buildout)
buildout: Develop: /sample-buildout/recipes
buildout: Uninstalling debug
buildout: Installing dir
dir: Creating directory my_directory
buildout: Installing debug
recipe recipes:debug
<BLANKLINE>
Now we remove the part from the configuration file.
>>> write(sample_buildout, 'buildout.cfg',
... """
... [buildout]
... develop = recipes
... parts = debug
...
... [debug]
... recipe = recipes:debug
... """)
When the buildout is run the part is removed, and the uninstall recipe
is run before the directory is deleted.
>>> print system(buildout)
buildout: Develop: /sample-buildout/recipes
buildout: Uninstalling dir
buildout: Running uninstall recipe
backing up directory /sample-buildout/my_directory of size 4096
buildout: Updating debug
recipe recipes:debug
<BLANKLINE>
Command-line usage
------------------
......@@ -895,8 +1128,7 @@ the buildout in the usual way:
>>> print system(buildout),
buildout: Develop: /sample-buildout/recipes
buildout: Uninstalling debug
buildout: Installing debug
buildout: Updating debug
recipe recipes:debug
buildout: Installing d1
d1: Creating directory d1
......
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