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Diffstat (limited to 'openstack/common/rootwrap/wrapper.py')
-rw-r--r-- | openstack/common/rootwrap/wrapper.py | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/openstack/common/rootwrap/wrapper.py b/openstack/common/rootwrap/wrapper.py new file mode 100644 index 0000000..d61c2be --- /dev/null +++ b/openstack/common/rootwrap/wrapper.py @@ -0,0 +1,149 @@ +# vim: tabstop=4 shiftwidth=4 softtabstop=4 + +# Copyright (c) 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. + + +import ConfigParser +import logging +import logging.handlers +import os +import string + +from openstack.common.rootwrap import filters + + +class NoFilterMatched(Exception): + """This exception is raised when no filter matched.""" + pass + + +class FilterMatchNotExecutable(Exception): + """ + This exception is raised when a filter matched but no executable was + found. + """ + def __init__(self, match=None, **kwargs): + self.match = match + + +class RootwrapConfig(object): + + def __init__(self, config): + # filters_path + self.filters_path = config.get("DEFAULT", "filters_path").split(",") + + # exec_dirs + if config.has_option("DEFAULT", "exec_dirs"): + self.exec_dirs = config.get("DEFAULT", "exec_dirs").split(",") + else: + # Use system PATH if exec_dirs is not specified + self.exec_dirs = os.environ["PATH"].split(':') + + # syslog_log_facility + if config.has_option("DEFAULT", "syslog_log_facility"): + v = config.get("DEFAULT", "syslog_log_facility") + facility_names = logging.handlers.SysLogHandler.facility_names + self.syslog_log_facility = getattr(logging.handlers.SysLogHandler, + v, None) + if self.syslog_log_facility is None and v in facility_names: + self.syslog_log_facility = facility_names.get(v) + if self.syslog_log_facility is None: + raise ValueError('Unexpected syslog_log_facility: %s' % v) + else: + default_facility = logging.handlers.SysLogHandler.LOG_SYSLOG + self.syslog_log_facility = default_facility + + # syslog_log_level + if config.has_option("DEFAULT", "syslog_log_level"): + v = config.get("DEFAULT", "syslog_log_level") + self.syslog_log_level = logging.getLevelName(v.upper()) + if (self.syslog_log_level == "Level %s" % v.upper()): + raise ValueError('Unexepected syslog_log_level: %s' % v) + else: + self.syslog_log_level = logging.ERROR + + # use_syslog + if config.has_option("DEFAULT", "use_syslog"): + self.use_syslog = config.getboolean("DEFAULT", "use_syslog") + else: + self.use_syslog = False + + +def setup_syslog(execname, facility, level): + rootwrap_logger = logging.getLogger() + rootwrap_logger.setLevel(level) + handler = logging.handlers.SysLogHandler(address='/dev/log', + facility=facility) + handler.setFormatter(logging.Formatter( + os.path.basename(execname) + ': %(message)s')) + rootwrap_logger.addHandler(handler) + + +def build_filter(class_name, *args): + """Returns a filter object of class class_name""" + if not hasattr(filters, class_name): + logging.warning("Skipping unknown filter class (%s) specified " + "in filter definitions" % class_name) + return None + filterclass = getattr(filters, class_name) + return filterclass(*args) + + +def load_filters(filters_path): + """Load filters from a list of directories""" + filterlist = [] + for filterdir in filters_path: + if not os.path.isdir(filterdir): + continue + for filterfile in os.listdir(filterdir): + filterconfig = ConfigParser.RawConfigParser() + filterconfig.read(os.path.join(filterdir, filterfile)) + for (name, value) in filterconfig.items("Filters"): + filterdefinition = [string.strip(s) for s in value.split(',')] + newfilter = build_filter(*filterdefinition) + if newfilter is None: + continue + newfilter.name = name + filterlist.append(newfilter) + return filterlist + + +def match_filter(filters, userargs, exec_dirs=[]): + """ + Checks user command and arguments through command filters and + returns the first matching filter. + Raises NoFilterMatched if no filter matched. + Raises FilterMatchNotExecutable if no executable was found for the + best filter match. + """ + first_not_executable_filter = None + + for f in filters: + if f.match(userargs): + # Try other filters if executable is absent + if not f.get_exec(exec_dirs=exec_dirs): + if not first_not_executable_filter: + first_not_executable_filter = f + continue + # Otherwise return matching filter for execution + return f + + if first_not_executable_filter: + # A filter matched, but no executable was found for it + raise FilterMatchNotExecutable(match=first_not_executable_filter) + + # No filter matched + raise NoFilterMatched() |