anvil/devstack/cfg.py
2012-03-15 16:53:50 -07:00

168 lines
6.4 KiB
Python

# vim: tabstop=4 shiftwidth=4 softtabstop=4
# Copyright (C) 2012 Yahoo! Inc. 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.
import re
import ConfigParser
from devstack import cfg_helpers
from devstack import date
from devstack import env
from devstack import exceptions as excp
from devstack import log as logging
from devstack import settings
from devstack import shell as sh
from devstack import utils
LOG = logging.getLogger("devstack.cfg")
ENV_PAT = re.compile(r"^\s*\$\{([\w\d]+):\-(.*)\}\s*$")
SUB_MATCH = re.compile(r"(?:\$\(([\w\d]+):([\w\d]+))\)")
CACHE_MSG = "(value will now be internally cached)"
def get_config(cfg_fn=None, cfg_cls=None):
if not cfg_fn:
cfg_fn = sh.canon_path(settings.STACK_CONFIG_LOCATION)
if not cfg_cls:
cfg_cls = StackConfigParser
config_instance = cfg_cls()
config_instance.read(cfg_fn)
return config_instance
class IgnoreMissingConfigParser(ConfigParser.RawConfigParser):
DEF_INT = 0
DEF_FLOAT = 0.0
DEF_BOOLEAN = False
DEF_BASE = None
def __init__(self):
ConfigParser.RawConfigParser.__init__(self)
#make option names case sensitive
self.optionxform = str
def get(self, section, option):
value = IgnoreMissingConfigParser.DEF_BASE
try:
value = ConfigParser.RawConfigParser.get(self, section, option)
except ConfigParser.NoSectionError:
pass
except ConfigParser.NoOptionError:
pass
return value
def getboolean(self, section, option):
if not self.has_option(section, option):
return IgnoreMissingConfigParser.DEF_BOOLEAN
return ConfigParser.RawConfigParser.getboolean(self, section, option)
def getfloat(self, section, option):
if not self.has_option(section, option):
return IgnoreMissingConfigParser.DEF_FLOAT
return ConfigParser.RawConfigParser.getfloat(self, section, option)
def getint(self, section, option):
if not self.has_option(section, option):
return IgnoreMissingConfigParser.DEF_INT
return ConfigParser.RawConfigParser.getint(self, section, option)
class StackConfigParser(IgnoreMissingConfigParser):
def __init__(self):
IgnoreMissingConfigParser.__init__(self)
self.configs_fetched = dict()
def _resolve_value(self, section, option, value_gotten):
if section == 'host' and option == 'ip':
LOG.debug("Host ip from configuration/environment was empty, programatically attempting to determine it.")
value_gotten = utils.get_host_ip()
LOG.debug("Determined your host ip to be: [%s]" % (value_gotten))
return value_gotten
def getdefaulted(self, section, option, default_val):
val = self.get(section, option)
if not val or not val.strip():
LOG.debug("Value [%s] found was not good enough, returning provided default [%s]" % (val, default_val))
return default_val
return val
def get(self, section, option):
key = cfg_helpers.make_id(section, option)
if key in self.configs_fetched:
value = self.configs_fetched.get(key)
LOG.debug("Fetched cached value [%s] for param [%s]" % (value, key))
else:
LOG.debug("Fetching value for param [%s]" % (key))
gotten_value = self._get_bashed(section, option)
value = self._resolve_value(section, option, gotten_value)
LOG.debug("Fetched [%s] for [%s] %s" % (value, key, CACHE_MSG))
self.configs_fetched[key] = value
return value
def set(self, section, option, value):
key = cfg_helpers.make_id(section, option)
LOG.audit("Setting config value [%s] for param [%s]" % (value, key))
self.configs_fetched[key] = value
IgnoreMissingConfigParser.set(self, section, option, value)
def _resolve_replacements(self, value):
LOG.debug("Performing simple replacement on [%s]", value)
#allow for our simple replacement to occur
def replacer(match):
section = match.group(1)
option = match.group(2)
return self.getdefaulted(section, option, '')
return SUB_MATCH.sub(replacer, value)
def _get_bashed(self, section, option):
value = IgnoreMissingConfigParser.get(self, section, option)
if value is None:
return value
extracted_val = ''
mtch = ENV_PAT.match(value)
if mtch:
env_key = mtch.group(1).strip()
def_val = mtch.group(2).strip()
if not def_val and not env_key:
msg = "Invalid bash-like value [%s]" % (value)
raise excp.BadParamException(msg)
env_value = env.get_key(env_key)
if env_value is None:
LOG.debug("Extracting value from config provided default value [%s]" % (def_val))
extracted_val = self._resolve_replacements(def_val)
LOG.debug("Using config provided default value [%s] (no environment key)" % (extracted_val))
else:
extracted_val = env_value
LOG.debug("Using enviroment provided value [%s]" % (extracted_val))
else:
extracted_val = value
LOG.debug("Using raw config provided value [%s]" % (extracted_val))
return extracted_val
def add_header(fn, contents):
lines = list()
lines.append('# Adjusted source file %s' % (fn.strip()))
lines.append("# On %s" % (date.rcf8222date()))
lines.append("# By user %s, group %s" % (sh.getuser(), sh.getgroupname()))
lines.append("# Comments may have been removed (TODO: darn python config writer)")
# TODO Maybe use https://code.google.com/p/iniparse/ which seems to preserve comments!
lines.append("")
if contents:
lines.append(contents)
return utils.joinlinesep(*lines)