Initial skeleton project

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diff --git a/openstack/common/config.py b/openstack/common/config.py
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+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+# Copyright 2011 OpenStack LLC.
+# All Rights Reserved.
+#
+#    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.
+
+"""
+Routines for configuring Openstack Projects
+"""
+
+import ConfigParser
+import logging
+import logging.config
+import logging.handlers
+import optparse
+import os
+import re
+import sys
+
+from paste import deploy
+
+DEFAULT_LOG_FORMAT = "%(asctime)s %(levelname)8s [%(name)s] %(message)s"
+DEFAULT_LOG_DATE_FORMAT = "%Y-%m-%d %H:%M:%S"
+
+
+def parse_options(parser, cli_args=None):
+    """
+    Returns the parsed CLI options, command to run and its arguments, merged
+    with any same-named options found in a configuration file.
+
+    The function returns a tuple of (options, args), where options is a
+    mapping of option key/str(value) pairs, and args is the set of arguments
+    (not options) supplied on the command-line.
+
+    The reason that the option values are returned as strings only is that
+    ConfigParser and paste.deploy only accept string values...
+
+    :param parser: The option parser
+    :param cli_args: (Optional) Set of arguments to process. If not present,
+                     sys.argv[1:] is used.
+    :retval tuple of (options, args)
+    """
+
+    (options, args) = parser.parse_args(cli_args)
+
+    return (vars(options), args)
+
+
+def add_common_options(parser):
+    """
+    Given a supplied optparse.OptionParser, adds an OptionGroup that
+    represents all common configuration options.
+
+    :param parser: optparse.OptionParser
+    """
+    help_text = "The following configuration options are common to "\
+                "all glance programs."
+
+    group = optparse.OptionGroup(parser, "Common Options", help_text)
+    group.add_option('-v', '--verbose', default=False, dest="verbose",
+                     action="store_true",
+                     help="Print more verbose output")
+    group.add_option('-d', '--debug', default=False, dest="debug",
+                     action="store_true",
+                     help="Print debugging output")
+    group.add_option('--config-file', default=None, metavar="PATH",
+                     help="Path to the config file to use. When not specified "
+                          "(the default), we generally look at the first "
+                          "argument specified to be a config file, and if "
+                          "that is also missing, we search standard "
+                          "directories for a config file.")
+    parser.add_option_group(group)
+
+
+def add_log_options(parser):
+    """
+    Given a supplied optparse.OptionParser, adds an OptionGroup that
+    represents all the configuration options around logging.
+
+    :param parser: optparse.OptionParser
+    """
+    help_text = "The following configuration options are specific to logging "\
+                "functionality for this program."
+
+    group = optparse.OptionGroup(parser, "Logging Options", help_text)
+    group.add_option('--log-config', default=None, metavar="PATH",
+                     help="If this option is specified, the logging "
+                          "configuration file specified is used and overrides "
+                          "any other logging options specified. Please see "
+                          "the Python logging module documentation for "
+                          "details on logging configuration files.")
+    group.add_option('--log-date-format', metavar="FORMAT",
+                      default=DEFAULT_LOG_DATE_FORMAT,
+                      help="Format string for %(asctime)s in log records. "
+                           "Default: %default")
+    group.add_option('--log-file', default=None, metavar="PATH",
+                      help="(Optional) Name of log file to output to. "
+                           "If not set, logging will go to stdout.")
+    group.add_option("--log-dir", default=None,
+                      help="(Optional) The directory to keep log files in "
+                           "(will be prepended to --logfile)")
+    parser.add_option_group(group)
+
+
+def setup_logging(options, conf):
+    """
+    Sets up the logging options for a log with supplied name
+
+    :param options: Mapping of typed option key/values
+    :param conf: Mapping of untyped key/values from config file
+    """
+
+    if options.get('log_config', None):
+        # Use a logging configuration file for all settings...
+        if os.path.exists(options['log_config']):
+            logging.config.fileConfig(options['log_config'])
+            return
+        else:
+            raise RuntimeError("Unable to locate specified logging "
+                               "config file: %s" % options['log_config'])
+
+    # If either the CLI option or the conf value
+    # is True, we set to True
+    debug = options.get('debug') or \
+            get_option(conf, 'debug', type='bool', default=False)
+    verbose = options.get('verbose') or \
+            get_option(conf, 'verbose', type='bool', default=False)
+    root_logger = logging.root
+    if debug:
+        root_logger.setLevel(logging.DEBUG)
+    elif verbose:
+        root_logger.setLevel(logging.INFO)
+    else:
+        root_logger.setLevel(logging.WARNING)
+
+    # Set log configuration from options...
+    # Note that we use a hard-coded log format in the options
+    # because of Paste.Deploy bug #379
+    # http://trac.pythonpaste.org/pythonpaste/ticket/379
+    log_format = options.get('log_format', DEFAULT_LOG_FORMAT)
+    log_date_format = options.get('log_date_format', DEFAULT_LOG_DATE_FORMAT)
+    formatter = logging.Formatter(log_format, log_date_format)
+
+    logfile = options.get('log_file')
+    if not logfile:
+        logfile = conf.get('log_file')
+
+    if logfile:
+        logdir = options.get('log_dir')
+        if not logdir:
+            logdir = conf.get('log_dir')
+        if logdir:
+            logfile = os.path.join(logdir, logfile)
+        logfile = logging.FileHandler(logfile)
+        logfile.setFormatter(formatter)
+        logfile.setFormatter(formatter)
+        root_logger.addHandler(logfile)
+    else:
+        handler = logging.StreamHandler(sys.stdout)
+        handler.setFormatter(formatter)
+        root_logger.addHandler(handler)
+
+
+def find_config_file(app_name, options, args):
+    """
+    Return the first config file found for an application.
+
+    We search for the paste config file in the following order:
+    * If --config-file option is used, use that
+    * If args[0] is a file, use that
+    * Search for $app.conf in standard directories:
+        * .
+        * ~.glance/
+        * ~
+        * /etc/glance
+        * /etc
+
+    :retval Full path to config file, or None if no config file found
+    """
+
+    fix_path = lambda p: os.path.abspath(os.path.expanduser(p))
+    if options.get('config_file'):
+        if os.path.exists(options['config_file']):
+            return fix_path(options['config_file'])
+    elif args:
+        if os.path.exists(args[0]):
+            return fix_path(args[0])
+
+    # Handle standard directory search for $app_name.conf
+    config_file_dirs = [fix_path(os.getcwd()),
+                        fix_path(os.path.join('~', '.glance')),
+                        fix_path('~'),
+                        '/etc/glance/',
+                        '/etc']
+
+    for cfg_dir in config_file_dirs:
+        cfg_file = os.path.join(cfg_dir, '%s.conf' % app_name)
+        if os.path.exists(cfg_file):
+            return cfg_file
+
+
+def load_paste_config(app_name, options, args):
+    """
+    Looks for a config file to use for an app and returns the
+    config file path and a configuration mapping from a paste config file.
+
+    We search for the paste config file in the following order:
+    * If --config-file option is used, use that
+    * If args[0] is a file, use that
+    * Search for $app_name.conf in standard directories:
+        * .
+        * ~.glance/
+        * ~
+        * /etc/glance
+        * /etc
+
+    :param app_name: Name of the application to load config for, or None.
+                     None signifies to only load the [DEFAULT] section of
+                     the config file.
+    :param options: Set of typed options returned from parse_options()
+    :param args: Command line arguments from argv[1:]
+    :retval Tuple of (conf_file, conf)
+
+    :raises RuntimeError when config file cannot be located or there was a
+            problem loading the configuration file.
+    """
+    conf_file = find_config_file(app_name, options, args)
+    if not conf_file:
+        raise RuntimeError("Unable to locate any configuration file. "
+                            "Cannot load application %s" % app_name)
+    try:
+        conf = deploy.appconfig("config:%s" % conf_file, name=app_name)
+        return conf_file, conf
+    except Exception, e:
+        raise RuntimeError("Error trying to load config %s: %s"
+                           % (conf_file, e))
+
+
+def load_paste_app(app_name, options, args):
+    """
+    Builds and returns a WSGI app from a paste config file.
+
+    We search for the paste config file in the following order:
+    * If --config-file option is used, use that
+    * If args[0] is a file, use that
+    * Search for $app_name.conf in standard directories:
+        * .
+        * ~.glance/
+        * ~
+        * /etc/glance
+        * /etc
+
+    :param app_name: Name of the application to load
+    :param options: Set of typed options returned from parse_options()
+    :param args: Command line arguments from argv[1:]
+
+    :raises RuntimeError when config file cannot be located or application
+            cannot be loaded from config file
+    """
+    conf_file, conf = load_paste_config(app_name, options, args)
+
+    try:
+        # Setup logging early, supplying both the CLI options and the
+        # configuration mapping from the config file
+        setup_logging(options, conf)
+
+        # We only update the conf dict for the verbose and debug
+        # flags. Everything else must be set up in the conf file...
+        debug = options.get('debug') or \
+                get_option(conf, 'debug', type='bool', default=False)
+        verbose = options.get('verbose') or \
+                get_option(conf, 'verbose', type='bool', default=False)
+        conf['debug'] = debug
+        conf['verbose'] = verbose
+
+        # Log the options used when starting if we're in debug mode...
+        if debug:
+            logger = logging.getLogger(app_name)
+            logger.debug("*" * 80)
+            logger.debug("Configuration options gathered from config file:")
+            logger.debug(conf_file)
+            logger.debug("================================================")
+            items = dict([(k, v) for k, v in conf.items()
+                          if k not in ('__file__', 'here')])
+            for key, value in sorted(items.items()):
+                logger.debug("%(key)-30s %(value)s" % locals())
+            logger.debug("*" * 80)
+        app = deploy.loadapp("config:%s" % conf_file, name=app_name)
+    except (LookupError, ImportError), e:
+        raise RuntimeError("Unable to load %(app_name)s from "
+                           "configuration file %(conf_file)s."
+                           "\nGot: %(e)r" % locals())
+    return conf, app
+
+
+def get_option(options, option, **kwargs):
+    if option in options:
+        value = options[option]
+        type_ = kwargs.get('type', 'str')
+        if type_ == 'bool':
+            if hasattr(value, 'lower'):
+                return value.lower() == 'true'
+            else:
+                return value
+        elif type_ == 'int':
+            return int(value)
+        elif type_ == 'float':
+            return float(value)
+        else:
+            return value
+    elif 'default' in kwargs:
+        return kwargs['default']
+    else:
+        raise KeyError("option '%s' not found" % option)