Sync to newer openstack-common

Changes since last sync are:

 - cfg:
    * Support for directory source of config files
    * Provide file extension when when looking for files
    * Some refactoring of the cfg cache
    * Add caching to openstack.common.cfg

 - setup:
    * Handle authors existed before VCS was around.

Change-Id: If3f0515a911a315dc1329b99299fdbc3592fce24

2 files changed, 91 insertions, 33 deletions

diff --git a/keystone/openstack/common/cfg.py b/keystone/openstack/common/cfg.py
index a83e8638..76f0e4d3 100644
--- a/keystone/openstack/common/cfg.py
+++ b/keystone/openstack/common/cfg.py
@@ -90,16 +90,21 @@ the purposes of --help and CLI arg validation)::
     def add_common_opts(conf):
         conf.register_cli_opts(cli_opts)
 
-The config manager has a single CLI option defined by default, --config-file::
+The config manager has two CLI options defined by default, --config-file
+and --config-dir::
 
     class ConfigOpts(object):
 
-        config_file_opt = MultiStrOpt('config-file',
-                                      ...
-
         def __init__(self, ...):
-            ...
-            self.register_cli_opt(self.config_file_opt)
+
+            opts = [
+                MultiStrOpt('config-file',
+                        ...),
+                StrOpt('config-dir',
+                       ...),
+            ]
+
+            self.register_cli_opts(opts)
 
 Option values are parsed from any supplied config files using
 openstack.common.iniparser. If none are specified, a default set is used
@@ -221,6 +226,8 @@ log files:
 
 import collections
 import copy
+import glob
+import functools
 import optparse
 import os
 import string
@@ -318,11 +325,12 @@ class ConfigFileValueError(Error):
     pass
 
 
-def find_config_files(project=None, prog=None):
+def find_config_files(project=None, prog=None, extension='.conf'):
     """Return a list of default configuration files.
 
     :param project: an optional project name
     :param prog: the program name, defaulting to the basename of sys.argv[0]
+    :param extension: the type of the config file
 
     We default to two config files: [${project}.conf, ${prog}.conf]
 
@@ -355,16 +363,16 @@ def find_config_files(project=None, prog=None):
         ]
     cfg_dirs = filter(bool, cfg_dirs)
 
-    def search_dirs(dirs, basename):
+    def search_dirs(dirs, basename, extension):
         for d in dirs:
-            path = os.path.join(d, basename)
+            path = os.path.join(d, '%s%s' % (basename, extension))
             if os.path.exists(path):
                 return path
 
     config_files = []
     if project:
-        config_files.append(search_dirs(cfg_dirs, '%s.conf' % project))
-    config_files.append(search_dirs(cfg_dirs, '%s.conf' % prog))
+        config_files.append(search_dirs(cfg_dirs, project, extension))
+    config_files.append(search_dirs(cfg_dirs, prog, extension))
 
     return filter(bool, config_files)
 
@@ -821,14 +829,37 @@ class ConfigOpts(collections.Mapping):
                                               usage=self.usage)
         self._cparser = None
 
-        self.register_cli_opt(
-            MultiStrOpt('config-file',
-                        default=self.default_config_files,
-                        metavar='PATH',
-                        help='Path to a config file to use. Multiple config '
-                             'files can be specified, with values in later '
-                             'files taking precedence. The default files used '
-                             'are: %s' % (self.default_config_files, )))
+        self.__cache = {}
+
+        opts = [
+             MultiStrOpt('config-file',
+                         default=self.default_config_files,
+                         metavar='PATH',
+                         help='Path to a config file to use. Multiple config '
+                              'files can be specified, with values in later '
+                              'files taking precedence. The default files '
+                              ' used are: %s' %
+                              (self.default_config_files, )),
+            StrOpt('config-dir',
+                   metavar='DIR',
+                   help='Path to a config directory to pull *.conf '
+                        'files from. This file set is sorted, so as to '
+                        'provide a predictable parse order if individual '
+                        'options are over-ridden. The set is parsed after '
+                        'the file(s), if any, specified via --config-file, '
+                        'hence over-ridden options in the directory take '
+                        'precedence.'),
+            ]
+        self.register_cli_opts(opts)
+
+    def __clear_cache(f):
+        @functools.wraps(f)
+        def __inner(self, *args, **kwargs):
+            if kwargs.pop('clear_cache', True):
+                self.__cache.clear()
+            return f(self, *args, **kwargs)
+
+        return __inner
 
     def __call__(self, args=None):
         """Parse command line arguments and config files.
@@ -840,6 +871,10 @@ class ConfigOpts(collections.Mapping):
         The object may be called multiple times, each time causing the previous
         set of values to be overwritten.
 
+        If the --config-dir option is set, any *.conf files from this
+        directory are pulled in, after all the file(s) specified by the
+        --config-file option.
+
         :params args: command line arguments (defaults to sys.argv[1:])
         :returns: the list of arguments left over after parsing options
         :raises: SystemExit, ConfigFilesNotFoundError, ConfigFileParseError
@@ -852,8 +887,14 @@ class ConfigOpts(collections.Mapping):
 
         self._cli_values = vars(values)
 
-        if self.config_file:
-            self._parse_config_files(self.config_file)
+        def _list_config_dir():
+            return sorted(glob.glob(os.path.join(self.config_dir, '*.conf')))
+
+        from_file = list(self.config_file)
+
+        from_dir = _list_config_dir() if self.config_dir else []
+
+        self._parse_config_files(from_file + from_dir)
 
         return args
 
@@ -864,7 +905,7 @@ class ConfigOpts(collections.Mapping):
         :returns: the option value (after string subsititution) or a GroupAttr
         :raises: NoSuchOptError,ConfigFileValueError,TemplateSubstitutionError
         """
-        return self._substitute(self._get(name))
+        return self._get(name)
 
     def __getitem__(self, key):
         """Look up an option value and perform string substitution."""
@@ -883,12 +924,14 @@ class ConfigOpts(collections.Mapping):
         """Return the number of options and option groups."""
         return len(self._opts) + len(self._groups)
 
+    @__clear_cache
     def reset(self):
         """Reset the state of the object to before it was called."""
         self._args = None
         self._cli_values = None
         self._cparser = None
 
+    @__clear_cache
     def register_opt(self, opt, group=None):
         """Register an option schema.
 
@@ -911,11 +954,13 @@ class ConfigOpts(collections.Mapping):
 
         return True
 
+    @__clear_cache
     def register_opts(self, opts, group=None):
         """Register multiple option schemas at once."""
         for opt in opts:
-            self.register_opt(opt, group)
+            self.register_opt(opt, group, clear_cache=False)
 
+    @__clear_cache
     def register_cli_opt(self, opt, group=None):
         """Register a CLI option schema.
 
@@ -931,7 +976,7 @@ class ConfigOpts(collections.Mapping):
         if self._args is not None:
             raise ArgsAlreadyParsedError("cannot register CLI option")
 
-        if not self.register_opt(opt, group):
+        if not self.register_opt(opt, group, clear_cache=False):
             return False
 
         if group is not None:
@@ -941,10 +986,11 @@ class ConfigOpts(collections.Mapping):
 
         return True
 
+    @__clear_cache
     def register_cli_opts(self, opts, group=None):
         """Register multiple CLI option schemas at once."""
         for opt in opts:
-            self.register_cli_opt(opt, group)
+            self.register_cli_opt(opt, group, clear_cache=False)
 
     def register_group(self, group):
         """Register an option group.
@@ -959,6 +1005,7 @@ class ConfigOpts(collections.Mapping):
 
         self._groups[group.name] = copy.copy(group)
 
+    @__clear_cache
     def set_override(self, name, override, group=None):
         """Override an opt value.
 
@@ -973,6 +1020,7 @@ class ConfigOpts(collections.Mapping):
         opt_info = self._get_opt_info(name, group)
         opt_info['override'] = override
 
+    @__clear_cache
     def set_default(self, name, default, group=None):
         """Override an opt's default value.
 
@@ -1056,6 +1104,18 @@ class ConfigOpts(collections.Mapping):
         self._oparser.print_help(file)
 
     def _get(self, name, group=None):
+        if isinstance(group, OptGroup):
+            key = (group.name, name)
+        else:
+            key = (group, name)
+        try:
+            return self.__cache[key]
+        except KeyError:
+            value = self._substitute(self._do_get(name, group))
+            self.__cache[key] = value
+            return value
+
+    def _do_get(self, name, group=None):
         """Look up an option value.
 
         :param name: the opt name (or 'dest', more precisely)
@@ -1196,7 +1256,7 @@ class ConfigOpts(collections.Mapping):
 
         def __getattr__(self, name):
             """Look up an option value and perform template substitution."""
-            return self.conf._substitute(self.conf._get(name, self.group))
+            return self.conf._get(name, self.group)
 
         def __getitem__(self, key):
             """Look up an option value and perform string substitution."""
diff --git a/keystone/openstack/common/setup.py b/keystone/openstack/common/setup.py
index 231b3384..60c731a9 100644
--- a/keystone/openstack/common/setup.py
+++ b/keystone/openstack/common/setup.py
@@ -138,10 +138,8 @@ def generate_authors():
                       "grep -v " + jenkins_email
         changelog = _run_shell_command(git_log_cmd)
         mailmap = parse_mailmap()
-        new_authors_fh = open(new_authors, "w")
-        new_authors_fh.write(canonicalize_emails(changelog, mailmap))
-        if os.path.exists(old_authors):
-            new_authors_fh.write("\n")
-            with open(old_authors, "r") as old_authors_fh:
-                new_authors_fh.write(''.join(old_authors_fh.readlines()))
-        new_authors_fh.close()
+        with open(new_authors, 'w') as new_authors_fh:
+            new_authors_fh.write(canonicalize_emails(changelog, mailmap))
+            if os.path.exists(old_authors):
+                with open(old_authors, "r") as old_authors_fh:
+                    new_authors_fh.write('\n' + old_authors_fh.read())