Expose lockutils opts to config generator

* Adds an opts module for the config generator to use.
* Makes the opts in lockutils private since we don't want consumers
  using them directly.
* Moves the options to an oslo_concurrency group with appropriate
  deprecated_group settings to keep existing configs working.

Change-Id: Ifdb4d99e27588e8a91d941c60b248ea526c06e0a

oslo/concurrency/lockutils.py

@@ -35,23 +35,25 @@ from oslo.concurrency.openstack.common import fileutils
 LOG = logging.getLogger(__name__)
 
 
-util_opts = [
+_opts = [
     cfg.BoolOpt('disable_process_locking', default=False,
-                help='Enables or disables inter-process locks.'),
+                help='Enables or disables inter-process locks.',
+                deprecated_group='DEFAULT'),
     cfg.StrOpt('lock_path',
                default=os.environ.get("OSLO_LOCK_PATH"),
                help='Directory to use for lock files.  For security, the '
                     'specified directory should only be writable by the user '
-                    'running the processes that need locking.')
+                    'running the processes that need locking.',
+               deprecated_group='DEFAULT')
 ]
 
 
 CONF = cfg.CONF
-CONF.register_opts(util_opts)
+CONF.register_opts(_opts, group='oslo_concurrency')
 
 
 def set_defaults(lock_path):
-    cfg.set_defaults(util_opts, lock_path=lock_path)
+    cfg.set_defaults(_opts, lock_path=lock_path)
 
 
 class _FileLock(object):
@@ -180,7 +182,7 @@ def _get_lock_path(name, lock_file_prefix, lock_path=None):
         sep = '' if lock_file_prefix.endswith('-') else '-'
         name = '%s%s%s' % (lock_file_prefix, sep, name)
 
-    local_lock_path = lock_path or CONF.lock_path
+    local_lock_path = lock_path or CONF.oslo_concurrency.lock_path
 
     if not local_lock_path:
         raise cfg.RequiredOptError('lock_path')
@@ -243,7 +245,7 @@ def lock(name, lock_file_prefix=None, external=False, lock_path=None):
     with int_lock:
         LOG.debug('Acquired semaphore "%(lock)s"', {'lock': name})
         try:
-            if external and not CONF.disable_process_locking:
+            if external and not CONF.oslo_concurrency.disable_process_locking:
                 ext_lock = external_lock(name, lock_file_prefix, lock_path)
                 with ext_lock:
                     yield ext_lock

oslo/concurrency/opts.py

@@ -0,0 +1,45 @@
+# Copyright 2014 Red Hat, Inc.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+
+__all__ = [
+    'list_opts',
+]
+
+
+import copy
+
+from oslo.concurrency import lockutils
+
+
+def list_opts():
+    """Return a list of oslo.config options available in the library.
+
+    The returned list includes all oslo.config options which may be registered
+    at runtime by the library.
+
+    Each element of the list is a tuple. The first element is the name of the
+    group under which the list of elements in the second element will be
+    registered. A group name of None corresponds to the [DEFAULT] group in
+    config files.
+
+    This function is also discoverable via the 'oslo.concurrency' entry point
+    under the 'oslo.config.opts' namespace.
+
+    The purpose of this is to allow tools like the Oslo sample config file
+    generator to discover the options exposed to users by this library.
+
+    :returns: a list of (group_name, opts) tuples
+    """
+    return [('oslo_concurrency', copy.deepcopy(lockutils._opts))]

setup.cfg

@@ -26,6 +26,10 @@ packages =
 namespace_packages =
     oslo
 
+[entry_points]
+oslo.config.opts =
+    oslo.concurrency = oslo.concurrency.opts:list_opts
+
 [build_sphinx]
 source-dir = doc/source
 build-dir = doc/build

tests/unit/test_lockutils.py

@@ -127,7 +127,7 @@ class LockTestCase(test_base.BaseTestCase):
         """We can nest external syncs."""
         tempdir = tempfile.mkdtemp()
         try:
-            self.config(lock_path=tempdir)
+            self.config(lock_path=tempdir, group='oslo_concurrency')
             sentinel = object()
 
             @lockutils.synchronized('testlock1', 'test-', external=True)
@@ -197,7 +197,7 @@ class LockTestCase(test_base.BaseTestCase):
 
     def test_lock_externally(self):
         lock_dir = tempfile.mkdtemp()
-        self.config(lock_path=lock_dir)
+        self.config(lock_path=lock_dir, group='oslo_concurrency')
 
         try:
             self._do_test_lock_externally()
@@ -208,7 +208,7 @@ class LockTestCase(test_base.BaseTestCase):
     def test_lock_externally_lock_dir_not_exist(self):
         lock_dir = tempfile.mkdtemp()
         os.rmdir(lock_dir)
-        self.config(lock_path=lock_dir)
+        self.config(lock_path=lock_dir, group='oslo_concurrency')
 
         try:
             self._do_test_lock_externally()
@@ -227,13 +227,13 @@ class LockTestCase(test_base.BaseTestCase):
             return True
 
         lock_dir = tempfile.mkdtemp()
-        self.config(lock_path=lock_dir)
+        self.config(lock_path=lock_dir, group='oslo_concurrency')
 
         self.assertTrue(bar(lock_dir, lock_pfix, lock_name))
 
     def test_synchronized_without_prefix(self):
         lock_dir = tempfile.mkdtemp()
-        self.config(lock_path=lock_dir)
+        self.config(lock_path=lock_dir, group='oslo_concurrency')
 
         @lockutils.synchronized('lock', external=True)
         def test_without_prefix():
@@ -248,7 +248,7 @@ class LockTestCase(test_base.BaseTestCase):
 
     def test_synchronized_prefix_without_hypen(self):
         lock_dir = tempfile.mkdtemp()
-        self.config(lock_path=lock_dir)
+        self.config(lock_path=lock_dir, group='oslo_concurrency')
 
         @lockutils.synchronized('lock', 'hypen', True)
         def test_without_hypen():
@@ -263,7 +263,7 @@ class LockTestCase(test_base.BaseTestCase):
 
     def test_contextlock(self):
         lock_dir = tempfile.mkdtemp()
-        self.config(lock_path=lock_dir)
+        self.config(lock_path=lock_dir, group='oslo_concurrency')
 
         try:
             # Note(flaper87): Lock is not external, which means
@@ -289,7 +289,7 @@ class LockTestCase(test_base.BaseTestCase):
 
     def test_contextlock_unlocks(self):
         lock_dir = tempfile.mkdtemp()
-        self.config(lock_path=lock_dir)
+        self.config(lock_path=lock_dir, group='oslo_concurrency')
 
         sem = None
 
@@ -334,7 +334,7 @@ class LockTestCase(test_base.BaseTestCase):
 
     def test_remove_lock_external_file(self):
         lock_dir = tempfile.mkdtemp()
-        self.config(lock_path=lock_dir)
+        self.config(lock_path=lock_dir, group='oslo_concurrency')
         self._test_remove_lock_external_file(lock_dir)
 
     def test_remove_lock_external_file_lock_path(self):
@@ -499,7 +499,7 @@ class TestLockFixture(test_base.BaseTestCase):
 
     def test_lock_fixture(self):
         # Setup lock fixture to test that teardown is inside the lock
-        self.config(lock_path=self.tempdir)
+        self.config(lock_path=self.tempdir, group='oslo_concurrency')
         fixture = fixtures.LockFixture('test-lock')
         self.useFixture(fixture)
         self.lock = fixture.lock