Remove support for command hooks

distutils2 is long dead and many of its best ideas have been
incorporated into setuptools. One of the ideas that *has not* been
incorporated is the idea of command hooks, of either the pre or post
kind. pbr is still carrying the code for this, and there are several
issues with this:

- No one is using this functionality in OpenStack and, given the
  complete lack of documentation on the matter, it's very doubtful that
  it's being used anywhere else [1]
- It's causing issues for projects attempting to hook into the
  'distutils.commands' entry point on Python 2.7, which it seems no else
  must have attempted yet [2].
- distutils2 is dead and advanced features like this that we don't
  explicitly need should not be retained

We could attempt to fix this but why bother? Good riddance, I say.

[1] http://codesearch.openstack.org/?q=pre_hook%5C.&i=nope&files=&repos=
[2] http://codesearch.openstack.org/?q=distutils.commands&i=nope&files=&repos=

Change-Id: I01f657034cffbf55ce830b7e8dbb6b3d94c1fd18

5 files changed, 6 insertions, 159 deletions

diff --git a/pbr/core.py b/pbr/core.py
index 71d1e56..753387e 100644
--- a/pbr/core.py
+++ b/pbr/core.py
@@ -141,16 +141,5 @@ def pbr(dist, attr, value):
         if isinstance(dist.metadata.version, integer_types + (float,)):
             # Some people apparently take "version number" too literally :)
             dist.metadata.version = str(dist.metadata.version)
-
-        # This bit of hackery is necessary so that the Distribution will ignore
-        # normally unsupport command options (namely pre-hooks and post-hooks).
-        # dist.command_options is normally a dict mapping command names to
-        # dicts of their options.  Now it will be a defaultdict that returns
-        # IgnoreDicts for the each command's options so we can pass through the
-        # unsupported options
-        ignore = ['pre_hook.*', 'post_hook.*']
-        dist.command_options = util.DefaultGetDict(
-            lambda: util.IgnoreDict(ignore)
-        )
     finally:
         _restore_distribution_monkeypatch()
diff --git a/pbr/tests/test_hooks.py b/pbr/tests/test_hooks.py
index 0759706..0fcf96c 100644
--- a/pbr/tests/test_hooks.py
+++ b/pbr/tests/test_hooks.py
@@ -39,9 +39,7 @@
 # BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 
 import os
-import textwrap
 
-from testtools import content
 from testtools import matchers
 
 from pbr.tests import base
@@ -56,10 +54,6 @@ class TestHooks(base.BaseTestCase):
             cfg.set('global', 'setup-hooks',
                     'pbr_testpackage._setup_hooks.test_hook_1\n'
                     'pbr_testpackage._setup_hooks.test_hook_2')
-            cfg.set('build_ext', 'pre-hook.test_pre_hook',
-                    'pbr_testpackage._setup_hooks.test_pre_hook')
-            cfg.set('build_ext', 'post-hook.test_post_hook',
-                    'pbr_testpackage._setup_hooks.test_post_hook')
 
     def test_global_setup_hooks(self):
         """Test setup_hooks.
@@ -72,28 +66,6 @@ class TestHooks(base.BaseTestCase):
         assert 'test_hook_1\ntest_hook_2' in stdout
         assert return_code == 0
 
-    def test_command_hooks(self):
-        """Test command hooks.
-
-        Simple test that the appropriate command hooks run at the
-        beginning/end of the appropriate command.
-        """
-
-        stdout, _, return_code = self.run_setup('egg_info')
-        assert 'build_ext pre-hook' not in stdout
-        assert 'build_ext post-hook' not in stdout
-        assert return_code == 0
-
-        stdout, stderr, return_code = self.run_setup('build_ext')
-        self.addDetailUniqueName('stderr', content.text_content(stderr))
-        assert textwrap.dedent("""
-            running build_ext
-            running pre_hook pbr_testpackage._setup_hooks.test_pre_hook for command build_ext
-            build_ext pre-hook
-        """) in stdout  # flake8: noqa
-        self.expectThat(stdout, matchers.EndsWith('build_ext post-hook'))
-        assert return_code == 0
-
     def test_custom_commands_known(self):
         stdout, _, return_code = self.run_setup('--help-commands')
         self.assertFalse(return_code)
diff --git a/pbr/tests/testpackage/setup.cfg b/pbr/tests/testpackage/setup.cfg
index 242c9c6..d10a87e 100644
--- a/pbr/tests/testpackage/setup.cfg
+++ b/pbr/tests/testpackage/setup.cfg
@@ -51,7 +51,3 @@ optional = True
 #    pbr_testpackage._setup_hooks.test_hook_1
 #    pbr_testpackage._setup_hooks.test_hook_2
 commands = pbr_testpackage._setup_hooks.test_command
-
-[build_ext]
-#pre-hook.test_pre_hook = pbr_testpackage._setup_hooks.test_pre_hook
-#post-hook.test_post_hook = pbr_testpackage._setup_hooks.test_post_hook
diff --git a/pbr/util.py b/pbr/util.py
index c07376e..dc8995e 100644
--- a/pbr/util.py
+++ b/pbr/util.py
@@ -264,8 +264,6 @@ def cfg_to_args(path='setup.cfg', script_args=()):
         if entry_points:
             kwargs['entry_points'] = entry_points
 
-        wrap_commands(kwargs)
-
         # Handle the [files]/extra_files option
         files_extra_files = has_get_option(config, 'files', 'extra_files')
         if files_extra_files:
@@ -552,103 +550,6 @@ def get_entry_points(config):
                 for option, value in config['entry_points'].items())
 
 
-def wrap_commands(kwargs):
-    dist = st_dist.Distribution()
-
-    # This should suffice to get the same config values and command classes
-    # that the actual Distribution will see (not counting cmdclass, which is
-    # handled below)
-    dist.parse_config_files()
-
-    # Setuptools doesn't patch get_command_list, and as such we do not get
-    # extra commands from entry_points.  As we need to be compatable we deal
-    # with this here.
-    for ep in pkg_resources.iter_entry_points('distutils.commands'):
-        if ep.name not in dist.cmdclass:
-            if hasattr(ep, 'resolve'):
-                cmdclass = ep.resolve()
-            else:
-                # Old setuptools does not have ep.resolve, and load with
-                # arguments is depricated in 11+.  Use resolve, 12+, if we
-                # can, otherwise fall back to load.
-                # Setuptools 11 will throw a deprication warning, as it
-                # uses _load instead of resolve.
-                cmdclass = ep.load(False)
-            dist.cmdclass[ep.name] = cmdclass
-
-    for cmd, _ in dist.get_command_list():
-        hooks = {}
-        for opt, val in dist.get_option_dict(cmd).items():
-            val = val[1]
-            if opt.startswith('pre_hook.') or opt.startswith('post_hook.'):
-                hook_type, alias = opt.split('.', 1)
-                hook_dict = hooks.setdefault(hook_type, {})
-                hook_dict[alias] = val
-        if not hooks:
-            continue
-
-        if 'cmdclass' in kwargs and cmd in kwargs['cmdclass']:
-            cmdclass = kwargs['cmdclass'][cmd]
-        else:
-            cmdclass = dist.get_command_class(cmd)
-
-        new_cmdclass = wrap_command(cmd, cmdclass, hooks)
-        kwargs.setdefault('cmdclass', {})[cmd] = new_cmdclass
-
-
-def wrap_command(cmd, cmdclass, hooks):
-    def run(self, cmdclass=cmdclass):
-        self.run_command_hooks('pre_hook')
-        cmdclass.run(self)
-        self.run_command_hooks('post_hook')
-
-    return type(cmd, (cmdclass, object),
-                {'run': run, 'run_command_hooks': run_command_hooks,
-                 'pre_hook': hooks.get('pre_hook'),
-                 'post_hook': hooks.get('post_hook')})
-
-
-def run_command_hooks(cmd_obj, hook_kind):
-    """Run hooks registered for that command and phase.
-
-    *cmd_obj* is a finalized command object; *hook_kind* is either
-    'pre_hook' or 'post_hook'.
-    """
-
-    if hook_kind not in ('pre_hook', 'post_hook'):
-        raise ValueError('invalid hook kind: %r' % hook_kind)
-
-    hooks = getattr(cmd_obj, hook_kind, None)
-
-    if hooks is None:
-        return
-
-    for hook in hooks.values():
-        if isinstance(hook, str):
-            try:
-                hook_obj = resolve_name(hook)
-            except ImportError:
-                err = sys.exc_info()[1] # For py3k
-                raise errors.DistutilsModuleError('cannot find hook %s: %s' %
-                                                  (hook,err))
-        else:
-            hook_obj = hook
-
-        if not hasattr(hook_obj, '__call__'):
-            raise errors.DistutilsOptionError('hook %r is not callable' % hook)
-
-        log.info('running %s %s for command %s',
-                 hook_kind, hook, cmd_obj.get_command_name())
-
-        try :
-            hook_obj(cmd_obj)
-        except:
-            e = sys.exc_info()[1]
-            log.error('hook %s raised exception: %s\n' % (hook, e))
-            log.error(traceback.format_exc())
-            sys.exit(1)
-
-
 def has_get_option(config, section, option):
     if section in config and option in config[section]:
         return config[section][option]
@@ -684,20 +585,3 @@ class DefaultGetDict(defaultdict):
         if default is None:
             default = self.default_factory()
         return super(DefaultGetDict, self).setdefault(key, default)
-
-
-class IgnoreDict(dict):
-    """A dictionary that ignores any insertions in which the key is a string
-    matching any string in `ignore`.  The ignore list can also contain wildcard
-    patterns using '*'.
-    """
-
-    def __init__(self, ignore):
-        self.__ignore = re.compile(r'(%s)' % ('|'.join(
-                                   [pat.replace('*', '.*')
-                                    for pat in ignore])))
-
-    def __setitem__(self, key, val):
-        if self.__ignore.match(key):
-            return
-        super(IgnoreDict, self).__setitem__(key, val)
diff --git a/releasenotes/notes/remove-command-hooks-907d9c2325f306ca.yaml b/releasenotes/notes/remove-command-hooks-907d9c2325f306ca.yaml
new file mode 100644
index 0000000..c6ce753
--- /dev/null
+++ b/releasenotes/notes/remove-command-hooks-907d9c2325f306ca.yaml
@@ -0,0 +1,6 @@
+---
+upgrade:
+  - |
+    Support for entry point command hooks has been removed. This feature was
+    poorly tested, poorly documented, and broken in some environments.
+    Support for global hooks is not affected.