oslo.config/oslo_config/generator.py

312 lines
10 KiB
Python

# Copyright 2012 SINA Corporation
# Copyright 2014 Cisco Systems, Inc.
# All Rights Reserved.
# 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.
"""Sample configuration generator
Tool for generating a sample configuration file. See
../doc/source/generator.rst for details.
.. versionadded:: 1.4
"""
import logging
import operator
import sys
import textwrap
import warnings
import pkg_resources
import six
from oslo_config import cfg
import stevedore.named # noqa
LOG = logging.getLogger(__name__)
_generator_opts = [
cfg.StrOpt('output-file',
help='Path of the file to write to. Defaults to stdout.'),
cfg.IntOpt('wrap-width',
default=70,
help='The maximum length of help lines.'),
cfg.MultiStrOpt('namespace',
help='Option namespace under "oslo.config.opts" in which '
'to query for options.'),
]
def register_cli_opts(conf):
"""Register the formatter's CLI options with a ConfigOpts instance.
Note, this must be done before the ConfigOpts instance is called to parse
the configuration.
:param conf: a ConfigOpts instance
:raises: DuplicateOptError, ArgsAlreadyParsedError
"""
conf.register_cli_opts(_generator_opts)
def _format_defaults(opt):
"Return a list of formatted default values."
if isinstance(opt, cfg.MultiStrOpt):
if opt.sample_default is not None:
defaults = opt.sample_default
elif not opt.default:
defaults = ['']
else:
defaults = opt.default
else:
if opt.sample_default is not None:
default_str = str(opt.sample_default)
elif opt.default is None:
default_str = '<None>'
elif (isinstance(opt, cfg.StrOpt) or
isinstance(opt, cfg.IPOpt)):
default_str = opt.default
elif isinstance(opt, cfg.BoolOpt):
default_str = str(opt.default).lower()
elif isinstance(opt, (cfg.IntOpt, cfg.FloatOpt,
cfg.PortOpt)):
default_str = str(opt.default)
elif isinstance(opt, cfg.ListOpt):
default_str = ','.join(opt.default)
elif isinstance(opt, cfg.DictOpt):
sorted_items = sorted(opt.default.items(),
key=operator.itemgetter(0))
default_str = ','.join(['%s:%s' % i for i in sorted_items])
else:
LOG.warning('Unknown option type: %s', repr(opt))
default_str = str(opt.default)
defaults = [default_str]
results = []
for default_str in defaults:
if default_str.strip() != default_str:
default_str = '"%s"' % default_str
results.append(default_str)
return results
class _OptFormatter(object):
"""Format configuration option descriptions to a file."""
def __init__(self, output_file=None, wrap_width=70):
"""Construct an OptFormatter object.
:param output_file: a writeable file object
:param wrap_width: The maximum length of help lines, 0 to not wrap
"""
self.output_file = output_file or sys.stdout
self.wrap_width = wrap_width
def _format_help(self, help_text):
"""Format the help for a group or option to the output file.
:param help_text: The text of the help string
"""
if self.wrap_width is not None and self.wrap_width > 0:
wrapped = ""
for line in help_text.splitlines():
text = "\n".join(textwrap.wrap(line, self.wrap_width,
initial_indent='# ',
subsequent_indent='# ',
break_long_words=False,
replace_whitespace=False))
wrapped += "#" if text == "" else text
wrapped += "\n"
lines = [wrapped]
else:
lines = ['# ' + help_text + '\n']
return lines
def _get_choice_text(self, choice):
if choice is None:
return '<None>'
elif choice == '':
return "''"
return six.text_type(choice)
def format_group(self, group_or_groupname):
"""Format the description of a group header to the output file
:param group_or_groupname: a cfg.OptGroup instance or a name of group
"""
if isinstance(group_or_groupname, cfg.OptGroup):
group = group_or_groupname
lines = ['[%s]\n' % group.name]
if group.help:
lines += self._format_help(group.help)
else:
groupname = group_or_groupname
lines = ['[%s]\n' % groupname]
self.writelines(lines)
def format(self, opt):
"""Format a description of an option to the output file.
:param opt: a cfg.Opt instance
"""
if not opt.help:
LOG.warning('"%s" is missing a help string', opt.dest)
option_type = getattr(opt, 'type', None)
opt_type = getattr(option_type, 'type_name', 'unknown value')
if opt.help:
help_text = u'%s (%s)' % (opt.help,
opt_type)
else:
help_text = u'(%s)' % opt_type
lines = self._format_help(help_text)
if getattr(opt.type, 'min', None):
lines.append('# Minimum value: %d\n' % opt.type.min)
if getattr(opt.type, 'max', None):
lines.append('# Maximum value: %d\n' % opt.type.max)
if getattr(opt.type, 'choices', None):
choices_text = ', '.join([self._get_choice_text(choice)
for choice in opt.type.choices])
lines.append('# Allowed values: %s\n' % choices_text)
for d in opt.deprecated_opts:
lines.append('# Deprecated group/name - [%s]/%s\n' %
(d.group or 'DEFAULT', d.name or opt.dest))
if opt.deprecated_for_removal:
lines.append(
'# This option is deprecated for removal.\n'
'# Its value may be silently ignored in the future.\n')
if hasattr(opt.type, 'format_defaults'):
defaults = opt.type.format_defaults(opt.default,
opt.sample_default)
else:
msg = ('Option %s should have a type derived from '
'types.ConfigType instead of %s' % (opt.name, opt.type))
warnings.warn(msg)
defaults = _format_defaults(opt)
for default_str in defaults:
if default_str:
default_str = ' ' + default_str
lines.append('#%s =%s\n' % (opt.dest, default_str))
self.writelines(lines)
def write(self, s):
"""Write an arbitrary string to the output file.
:param s: an arbitrary string
"""
self.output_file.write(s)
def writelines(self, l):
"""Write an arbitrary sequence of strings to the output file.
:param l: a list of arbitrary strings
"""
self.output_file.writelines(l)
def _list_opts(namespaces):
"""List the options available via the given namespaces.
:param namespaces: a list of namespaces registered under 'oslo.config.opts'
:returns: a list of (namespace, [(group, [opt_1, opt_2])]) tuples
"""
mgr = stevedore.named.NamedExtensionManager(
'oslo.config.opts',
names=namespaces,
on_load_failure_callback=on_load_failure_callback,
invoke_on_load=True)
return [(ep.name, ep.obj) for ep in mgr]
def on_load_failure_callback(*args, **kwargs):
raise
def generate(conf):
"""Generate a sample config file.
List all of the options available via the namespaces specified in the given
configuration and write a description of them to the specified output file.
:param conf: a ConfigOpts instance containing the generator's configuration
"""
conf.register_opts(_generator_opts)
output_file = (open(conf.output_file, 'w')
if conf.output_file else sys.stdout)
formatter = _OptFormatter(output_file=output_file,
wrap_width=conf.wrap_width)
groups = {'DEFAULT': []}
for namespace, listing in _list_opts(conf.namespace):
for group, opts in listing:
if not opts:
continue
namespaces = groups.setdefault(group or 'DEFAULT', [])
namespaces.append((namespace, opts))
def _output_opts(f, group, namespaces):
f.format_group(group)
for (namespace, opts) in sorted(namespaces,
key=operator.itemgetter(0)):
f.write('\n#\n# From %s\n#\n' % namespace)
for opt in opts:
f.write('\n')
f.format(opt)
def _get_group_name(item):
group = item[0]
# The keys of the groups dictionary could be an OptGroup. Otherwise the
# help text of an OptGroup wouldn't be part of the generated sample
# file. It could also be just a plain group name without any further
# attributes. That's the reason why we have to distinct this here.
if isinstance(group, cfg.OptGroup):
group_name = group.name
else:
group_name = group
return group_name
# Output the "DEFAULT" section as the very first section
_output_opts(formatter, 'DEFAULT', groups.pop('DEFAULT'))
# output all other config sections with opts in alphabetical order
for group, namespaces in sorted(groups.items(), key=_get_group_name):
formatter.write('\n\n')
_output_opts(formatter, group, namespaces)
def main(args=None):
"""The main function of oslo-config-generator."""
version = pkg_resources.get_distribution('oslo.config').version
logging.basicConfig(level=logging.WARN)
conf = cfg.ConfigOpts()
register_cli_opts(conf)
conf(args, version=version)
generate(conf)
if __name__ == '__main__':
main()