979 lines
29 KiB
Python
979 lines
29 KiB
Python
# Copyright 2014-2015 Canonical Limited.
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#
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# This file is part of charm-helpers.
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#
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# charm-helpers is free software: you can redistribute it and/or modify
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# it under the terms of the GNU Lesser General Public License version 3 as
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# published by the Free Software Foundation.
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#
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# charm-helpers is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU Lesser General Public License for more details.
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#
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# You should have received a copy of the GNU Lesser General Public License
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# along with charm-helpers. If not, see <http://www.gnu.org/licenses/>.
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"Interactions with the Juju environment"
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# Copyright 2013 Canonical Ltd.
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#
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# Authors:
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# Charm Helpers Developers <juju@lists.ubuntu.com>
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from __future__ import print_function
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import copy
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from distutils.version import LooseVersion
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from functools import wraps
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import glob
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import os
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import json
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import yaml
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import subprocess
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import sys
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import errno
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import tempfile
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from subprocess import CalledProcessError
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import six
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if not six.PY3:
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from UserDict import UserDict
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else:
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from collections import UserDict
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CRITICAL = "CRITICAL"
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ERROR = "ERROR"
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WARNING = "WARNING"
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INFO = "INFO"
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DEBUG = "DEBUG"
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MARKER = object()
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cache = {}
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def cached(func):
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"""Cache return values for multiple executions of func + args
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For example::
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@cached
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def unit_get(attribute):
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pass
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unit_get('test')
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will cache the result of unit_get + 'test' for future calls.
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"""
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@wraps(func)
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def wrapper(*args, **kwargs):
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global cache
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key = str((func, args, kwargs))
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try:
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return cache[key]
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except KeyError:
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pass # Drop out of the exception handler scope.
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res = func(*args, **kwargs)
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cache[key] = res
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return res
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wrapper._wrapped = func
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return wrapper
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def flush(key):
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"""Flushes any entries from function cache where the
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key is found in the function+args """
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flush_list = []
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for item in cache:
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if key in item:
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flush_list.append(item)
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for item in flush_list:
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del cache[item]
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def log(message, level=None):
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"""Write a message to the juju log"""
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command = ['juju-log']
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if level:
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command += ['-l', level]
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if not isinstance(message, six.string_types):
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message = repr(message)
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command += [message]
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# Missing juju-log should not cause failures in unit tests
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# Send log output to stderr
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try:
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subprocess.call(command)
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except OSError as e:
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if e.errno == errno.ENOENT:
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if level:
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message = "{}: {}".format(level, message)
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message = "juju-log: {}".format(message)
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print(message, file=sys.stderr)
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else:
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raise
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class Serializable(UserDict):
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"""Wrapper, an object that can be serialized to yaml or json"""
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def __init__(self, obj):
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# wrap the object
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UserDict.__init__(self)
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self.data = obj
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def __getattr__(self, attr):
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# See if this object has attribute.
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if attr in ("json", "yaml", "data"):
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return self.__dict__[attr]
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# Check for attribute in wrapped object.
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got = getattr(self.data, attr, MARKER)
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if got is not MARKER:
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return got
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# Proxy to the wrapped object via dict interface.
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try:
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return self.data[attr]
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except KeyError:
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raise AttributeError(attr)
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def __getstate__(self):
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# Pickle as a standard dictionary.
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return self.data
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def __setstate__(self, state):
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# Unpickle into our wrapper.
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self.data = state
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def json(self):
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"""Serialize the object to json"""
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return json.dumps(self.data)
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def yaml(self):
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"""Serialize the object to yaml"""
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return yaml.dump(self.data)
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def execution_environment():
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"""A convenient bundling of the current execution context"""
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context = {}
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context['conf'] = config()
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if relation_id():
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context['reltype'] = relation_type()
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context['relid'] = relation_id()
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context['rel'] = relation_get()
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context['unit'] = local_unit()
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context['rels'] = relations()
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context['env'] = os.environ
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return context
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def in_relation_hook():
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"""Determine whether we're running in a relation hook"""
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return 'JUJU_RELATION' in os.environ
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def relation_type():
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"""The scope for the current relation hook"""
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return os.environ.get('JUJU_RELATION', None)
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@cached
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def relation_id(relation_name=None, service_or_unit=None):
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"""The relation ID for the current or a specified relation"""
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if not relation_name and not service_or_unit:
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return os.environ.get('JUJU_RELATION_ID', None)
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elif relation_name and service_or_unit:
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service_name = service_or_unit.split('/')[0]
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for relid in relation_ids(relation_name):
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remote_service = remote_service_name(relid)
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if remote_service == service_name:
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return relid
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else:
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raise ValueError('Must specify neither or both of relation_name and service_or_unit')
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def local_unit():
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"""Local unit ID"""
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return os.environ['JUJU_UNIT_NAME']
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def remote_unit():
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"""The remote unit for the current relation hook"""
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return os.environ.get('JUJU_REMOTE_UNIT', None)
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def service_name():
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"""The name service group this unit belongs to"""
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return local_unit().split('/')[0]
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@cached
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def remote_service_name(relid=None):
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"""The remote service name for a given relation-id (or the current relation)"""
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if relid is None:
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unit = remote_unit()
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else:
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units = related_units(relid)
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unit = units[0] if units else None
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return unit.split('/')[0] if unit else None
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def hook_name():
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"""The name of the currently executing hook"""
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return os.environ.get('JUJU_HOOK_NAME', os.path.basename(sys.argv[0]))
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class Config(dict):
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"""A dictionary representation of the charm's config.yaml, with some
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extra features:
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- See which values in the dictionary have changed since the previous hook.
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- For values that have changed, see what the previous value was.
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- Store arbitrary data for use in a later hook.
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NOTE: Do not instantiate this object directly - instead call
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``hookenv.config()``, which will return an instance of :class:`Config`.
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Example usage::
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>>> # inside a hook
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>>> from charmhelpers.core import hookenv
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>>> config = hookenv.config()
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>>> config['foo']
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'bar'
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>>> # store a new key/value for later use
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>>> config['mykey'] = 'myval'
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>>> # user runs `juju set mycharm foo=baz`
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>>> # now we're inside subsequent config-changed hook
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>>> config = hookenv.config()
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>>> config['foo']
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'baz'
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>>> # test to see if this val has changed since last hook
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>>> config.changed('foo')
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True
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>>> # what was the previous value?
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>>> config.previous('foo')
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'bar'
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>>> # keys/values that we add are preserved across hooks
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>>> config['mykey']
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'myval'
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"""
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CONFIG_FILE_NAME = '.juju-persistent-config'
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def __init__(self, *args, **kw):
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super(Config, self).__init__(*args, **kw)
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self.implicit_save = True
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self._prev_dict = None
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self.path = os.path.join(charm_dir(), Config.CONFIG_FILE_NAME)
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if os.path.exists(self.path):
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self.load_previous()
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atexit(self._implicit_save)
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def load_previous(self, path=None):
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"""Load previous copy of config from disk.
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In normal usage you don't need to call this method directly - it
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is called automatically at object initialization.
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:param path:
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File path from which to load the previous config. If `None`,
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config is loaded from the default location. If `path` is
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specified, subsequent `save()` calls will write to the same
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path.
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"""
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self.path = path or self.path
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with open(self.path) as f:
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self._prev_dict = json.load(f)
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for k, v in copy.deepcopy(self._prev_dict).items():
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if k not in self:
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self[k] = v
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def changed(self, key):
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"""Return True if the current value for this key is different from
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the previous value.
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"""
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if self._prev_dict is None:
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return True
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return self.previous(key) != self.get(key)
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def previous(self, key):
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"""Return previous value for this key, or None if there
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is no previous value.
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"""
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if self._prev_dict:
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return self._prev_dict.get(key)
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return None
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def save(self):
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"""Save this config to disk.
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If the charm is using the :mod:`Services Framework <services.base>`
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or :meth:'@hook <Hooks.hook>' decorator, this
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is called automatically at the end of successful hook execution.
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Otherwise, it should be called directly by user code.
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To disable automatic saves, set ``implicit_save=False`` on this
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instance.
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"""
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with open(self.path, 'w') as f:
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json.dump(self, f)
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def _implicit_save(self):
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if self.implicit_save:
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self.save()
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@cached
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def config(scope=None):
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"""Juju charm configuration"""
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config_cmd_line = ['config-get']
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if scope is not None:
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config_cmd_line.append(scope)
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config_cmd_line.append('--format=json')
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try:
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config_data = json.loads(
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subprocess.check_output(config_cmd_line).decode('UTF-8'))
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if scope is not None:
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return config_data
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return Config(config_data)
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except ValueError:
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return None
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@cached
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def relation_get(attribute=None, unit=None, rid=None):
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"""Get relation information"""
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_args = ['relation-get', '--format=json']
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if rid:
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_args.append('-r')
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_args.append(rid)
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_args.append(attribute or '-')
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if unit:
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_args.append(unit)
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try:
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return json.loads(subprocess.check_output(_args).decode('UTF-8'))
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except ValueError:
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return None
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except CalledProcessError as e:
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if e.returncode == 2:
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return None
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raise
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def relation_set(relation_id=None, relation_settings=None, **kwargs):
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"""Set relation information for the current unit"""
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relation_settings = relation_settings if relation_settings else {}
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relation_cmd_line = ['relation-set']
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accepts_file = "--file" in subprocess.check_output(
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relation_cmd_line + ["--help"], universal_newlines=True)
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if relation_id is not None:
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relation_cmd_line.extend(('-r', relation_id))
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settings = relation_settings.copy()
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settings.update(kwargs)
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for key, value in settings.items():
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# Force value to be a string: it always should, but some call
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# sites pass in things like dicts or numbers.
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if value is not None:
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settings[key] = "{}".format(value)
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if accepts_file:
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# --file was introduced in Juju 1.23.2. Use it by default if
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# available, since otherwise we'll break if the relation data is
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# too big. Ideally we should tell relation-set to read the data from
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# stdin, but that feature is broken in 1.23.2: Bug #1454678.
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with tempfile.NamedTemporaryFile(delete=False) as settings_file:
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settings_file.write(yaml.safe_dump(settings).encode("utf-8"))
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subprocess.check_call(
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relation_cmd_line + ["--file", settings_file.name])
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os.remove(settings_file.name)
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else:
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for key, value in settings.items():
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if value is None:
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relation_cmd_line.append('{}='.format(key))
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else:
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relation_cmd_line.append('{}={}'.format(key, value))
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subprocess.check_call(relation_cmd_line)
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# Flush cache of any relation-gets for local unit
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flush(local_unit())
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def relation_clear(r_id=None):
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''' Clears any relation data already set on relation r_id '''
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settings = relation_get(rid=r_id,
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unit=local_unit())
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for setting in settings:
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if setting not in ['public-address', 'private-address']:
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settings[setting] = None
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relation_set(relation_id=r_id,
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**settings)
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@cached
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def relation_ids(reltype=None):
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"""A list of relation_ids"""
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reltype = reltype or relation_type()
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relid_cmd_line = ['relation-ids', '--format=json']
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if reltype is not None:
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relid_cmd_line.append(reltype)
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return json.loads(
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subprocess.check_output(relid_cmd_line).decode('UTF-8')) or []
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return []
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@cached
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def related_units(relid=None):
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"""A list of related units"""
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relid = relid or relation_id()
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units_cmd_line = ['relation-list', '--format=json']
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if relid is not None:
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units_cmd_line.extend(('-r', relid))
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return json.loads(
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subprocess.check_output(units_cmd_line).decode('UTF-8')) or []
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@cached
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def relation_for_unit(unit=None, rid=None):
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"""Get the json represenation of a unit's relation"""
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unit = unit or remote_unit()
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relation = relation_get(unit=unit, rid=rid)
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for key in relation:
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if key.endswith('-list'):
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relation[key] = relation[key].split()
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relation['__unit__'] = unit
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return relation
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@cached
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def relations_for_id(relid=None):
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"""Get relations of a specific relation ID"""
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relation_data = []
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relid = relid or relation_ids()
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for unit in related_units(relid):
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unit_data = relation_for_unit(unit, relid)
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unit_data['__relid__'] = relid
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relation_data.append(unit_data)
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return relation_data
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@cached
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def relations_of_type(reltype=None):
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"""Get relations of a specific type"""
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relation_data = []
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reltype = reltype or relation_type()
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for relid in relation_ids(reltype):
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for relation in relations_for_id(relid):
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relation['__relid__'] = relid
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relation_data.append(relation)
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return relation_data
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@cached
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def metadata():
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"""Get the current charm metadata.yaml contents as a python object"""
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with open(os.path.join(charm_dir(), 'metadata.yaml')) as md:
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return yaml.safe_load(md)
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@cached
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def relation_types():
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"""Get a list of relation types supported by this charm"""
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rel_types = []
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md = metadata()
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for key in ('provides', 'requires', 'peers'):
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section = md.get(key)
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if section:
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rel_types.extend(section.keys())
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return rel_types
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@cached
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def peer_relation_id():
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'''Get the peers relation id if a peers relation has been joined, else None.'''
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md = metadata()
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section = md.get('peers')
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if section:
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for key in section:
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relids = relation_ids(key)
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if relids:
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return relids[0]
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return None
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@cached
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def relation_to_interface(relation_name):
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"""
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Given the name of a relation, return the interface that relation uses.
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:returns: The interface name, or ``None``.
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"""
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return relation_to_role_and_interface(relation_name)[1]
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@cached
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def relation_to_role_and_interface(relation_name):
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"""
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Given the name of a relation, return the role and the name of the interface
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that relation uses (where role is one of ``provides``, ``requires``, or ``peers``).
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:returns: A tuple containing ``(role, interface)``, or ``(None, None)``.
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"""
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_metadata = metadata()
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for role in ('provides', 'requires', 'peers'):
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interface = _metadata.get(role, {}).get(relation_name, {}).get('interface')
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if interface:
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return role, interface
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return None, None
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@cached
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def role_and_interface_to_relations(role, interface_name):
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"""
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Given a role and interface name, return a list of relation names for the
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current charm that use that interface under that role (where role is one
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of ``provides``, ``requires``, or ``peers``).
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:returns: A list of relation names.
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"""
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_metadata = metadata()
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results = []
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for relation_name, relation in _metadata.get(role, {}).items():
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if relation['interface'] == interface_name:
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results.append(relation_name)
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return results
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@cached
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def interface_to_relations(interface_name):
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"""
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Given an interface, return a list of relation names for the current
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charm that use that interface.
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:returns: A list of relation names.
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"""
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results = []
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for role in ('provides', 'requires', 'peers'):
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results.extend(role_and_interface_to_relations(role, interface_name))
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return results
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@cached
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|
def charm_name():
|
|
"""Get the name of the current charm as is specified on metadata.yaml"""
|
|
return metadata().get('name')
|
|
|
|
|
|
@cached
|
|
def relations():
|
|
"""Get a nested dictionary of relation data for all related units"""
|
|
rels = {}
|
|
for reltype in relation_types():
|
|
relids = {}
|
|
for relid in relation_ids(reltype):
|
|
units = {local_unit(): relation_get(unit=local_unit(), rid=relid)}
|
|
for unit in related_units(relid):
|
|
reldata = relation_get(unit=unit, rid=relid)
|
|
units[unit] = reldata
|
|
relids[relid] = units
|
|
rels[reltype] = relids
|
|
return rels
|
|
|
|
|
|
@cached
|
|
def is_relation_made(relation, keys='private-address'):
|
|
'''
|
|
Determine whether a relation is established by checking for
|
|
presence of key(s). If a list of keys is provided, they
|
|
must all be present for the relation to be identified as made
|
|
'''
|
|
if isinstance(keys, str):
|
|
keys = [keys]
|
|
for r_id in relation_ids(relation):
|
|
for unit in related_units(r_id):
|
|
context = {}
|
|
for k in keys:
|
|
context[k] = relation_get(k, rid=r_id,
|
|
unit=unit)
|
|
if None not in context.values():
|
|
return True
|
|
return False
|
|
|
|
|
|
def open_port(port, protocol="TCP"):
|
|
"""Open a service network port"""
|
|
_args = ['open-port']
|
|
_args.append('{}/{}'.format(port, protocol))
|
|
subprocess.check_call(_args)
|
|
|
|
|
|
def close_port(port, protocol="TCP"):
|
|
"""Close a service network port"""
|
|
_args = ['close-port']
|
|
_args.append('{}/{}'.format(port, protocol))
|
|
subprocess.check_call(_args)
|
|
|
|
|
|
@cached
|
|
def unit_get(attribute):
|
|
"""Get the unit ID for the remote unit"""
|
|
_args = ['unit-get', '--format=json', attribute]
|
|
try:
|
|
return json.loads(subprocess.check_output(_args).decode('UTF-8'))
|
|
except ValueError:
|
|
return None
|
|
|
|
|
|
def unit_public_ip():
|
|
"""Get this unit's public IP address"""
|
|
return unit_get('public-address')
|
|
|
|
|
|
def unit_private_ip():
|
|
"""Get this unit's private IP address"""
|
|
return unit_get('private-address')
|
|
|
|
|
|
@cached
|
|
def storage_get(attribute=None, storage_id=None):
|
|
"""Get storage attributes"""
|
|
_args = ['storage-get', '--format=json']
|
|
if storage_id:
|
|
_args.extend(('-s', storage_id))
|
|
if attribute:
|
|
_args.append(attribute)
|
|
try:
|
|
return json.loads(subprocess.check_output(_args).decode('UTF-8'))
|
|
except ValueError:
|
|
return None
|
|
|
|
|
|
@cached
|
|
def storage_list(storage_name=None):
|
|
"""List the storage IDs for the unit"""
|
|
_args = ['storage-list', '--format=json']
|
|
if storage_name:
|
|
_args.append(storage_name)
|
|
try:
|
|
return json.loads(subprocess.check_output(_args).decode('UTF-8'))
|
|
except ValueError:
|
|
return None
|
|
except OSError as e:
|
|
import errno
|
|
if e.errno == errno.ENOENT:
|
|
# storage-list does not exist
|
|
return []
|
|
raise
|
|
|
|
|
|
class UnregisteredHookError(Exception):
|
|
"""Raised when an undefined hook is called"""
|
|
pass
|
|
|
|
|
|
class Hooks(object):
|
|
"""A convenient handler for hook functions.
|
|
|
|
Example::
|
|
|
|
hooks = Hooks()
|
|
|
|
# register a hook, taking its name from the function name
|
|
@hooks.hook()
|
|
def install():
|
|
pass # your code here
|
|
|
|
# register a hook, providing a custom hook name
|
|
@hooks.hook("config-changed")
|
|
def config_changed():
|
|
pass # your code here
|
|
|
|
if __name__ == "__main__":
|
|
# execute a hook based on the name the program is called by
|
|
hooks.execute(sys.argv)
|
|
"""
|
|
|
|
def __init__(self, config_save=None):
|
|
super(Hooks, self).__init__()
|
|
self._hooks = {}
|
|
|
|
# For unknown reasons, we allow the Hooks constructor to override
|
|
# config().implicit_save.
|
|
if config_save is not None:
|
|
config().implicit_save = config_save
|
|
|
|
def register(self, name, function):
|
|
"""Register a hook"""
|
|
self._hooks[name] = function
|
|
|
|
def execute(self, args):
|
|
"""Execute a registered hook based on args[0]"""
|
|
_run_atstart()
|
|
hook_name = os.path.basename(args[0])
|
|
if hook_name in self._hooks:
|
|
try:
|
|
self._hooks[hook_name]()
|
|
except SystemExit as x:
|
|
if x.code is None or x.code == 0:
|
|
_run_atexit()
|
|
raise
|
|
_run_atexit()
|
|
else:
|
|
raise UnregisteredHookError(hook_name)
|
|
|
|
def hook(self, *hook_names):
|
|
"""Decorator, registering them as hooks"""
|
|
def wrapper(decorated):
|
|
for hook_name in hook_names:
|
|
self.register(hook_name, decorated)
|
|
else:
|
|
self.register(decorated.__name__, decorated)
|
|
if '_' in decorated.__name__:
|
|
self.register(
|
|
decorated.__name__.replace('_', '-'), decorated)
|
|
return decorated
|
|
return wrapper
|
|
|
|
|
|
def charm_dir():
|
|
"""Return the root directory of the current charm"""
|
|
return os.environ.get('CHARM_DIR')
|
|
|
|
|
|
@cached
|
|
def action_get(key=None):
|
|
"""Gets the value of an action parameter, or all key/value param pairs"""
|
|
cmd = ['action-get']
|
|
if key is not None:
|
|
cmd.append(key)
|
|
cmd.append('--format=json')
|
|
action_data = json.loads(subprocess.check_output(cmd).decode('UTF-8'))
|
|
return action_data
|
|
|
|
|
|
def action_set(values):
|
|
"""Sets the values to be returned after the action finishes"""
|
|
cmd = ['action-set']
|
|
for k, v in list(values.items()):
|
|
cmd.append('{}={}'.format(k, v))
|
|
subprocess.check_call(cmd)
|
|
|
|
|
|
def action_fail(message):
|
|
"""Sets the action status to failed and sets the error message.
|
|
|
|
The results set by action_set are preserved."""
|
|
subprocess.check_call(['action-fail', message])
|
|
|
|
|
|
def action_name():
|
|
"""Get the name of the currently executing action."""
|
|
return os.environ.get('JUJU_ACTION_NAME')
|
|
|
|
|
|
def action_uuid():
|
|
"""Get the UUID of the currently executing action."""
|
|
return os.environ.get('JUJU_ACTION_UUID')
|
|
|
|
|
|
def action_tag():
|
|
"""Get the tag for the currently executing action."""
|
|
return os.environ.get('JUJU_ACTION_TAG')
|
|
|
|
|
|
def status_set(workload_state, message):
|
|
"""Set the workload state with a message
|
|
|
|
Use status-set to set the workload state with a message which is visible
|
|
to the user via juju status. If the status-set command is not found then
|
|
assume this is juju < 1.23 and juju-log the message unstead.
|
|
|
|
workload_state -- valid juju workload state.
|
|
message -- status update message
|
|
"""
|
|
valid_states = ['maintenance', 'blocked', 'waiting', 'active']
|
|
if workload_state not in valid_states:
|
|
raise ValueError(
|
|
'{!r} is not a valid workload state'.format(workload_state)
|
|
)
|
|
cmd = ['status-set', workload_state, message]
|
|
try:
|
|
ret = subprocess.call(cmd)
|
|
if ret == 0:
|
|
return
|
|
except OSError as e:
|
|
if e.errno != errno.ENOENT:
|
|
raise
|
|
log_message = 'status-set failed: {} {}'.format(workload_state,
|
|
message)
|
|
log(log_message, level='INFO')
|
|
|
|
|
|
def status_get():
|
|
"""Retrieve the previously set juju workload state and message
|
|
|
|
If the status-get command is not found then assume this is juju < 1.23 and
|
|
return 'unknown', ""
|
|
|
|
"""
|
|
cmd = ['status-get', "--format=json", "--include-data"]
|
|
try:
|
|
raw_status = subprocess.check_output(cmd)
|
|
except OSError as e:
|
|
if e.errno == errno.ENOENT:
|
|
return ('unknown', "")
|
|
else:
|
|
raise
|
|
else:
|
|
status = json.loads(raw_status.decode("UTF-8"))
|
|
return (status["status"], status["message"])
|
|
|
|
|
|
def translate_exc(from_exc, to_exc):
|
|
def inner_translate_exc1(f):
|
|
@wraps(f)
|
|
def inner_translate_exc2(*args, **kwargs):
|
|
try:
|
|
return f(*args, **kwargs)
|
|
except from_exc:
|
|
raise to_exc
|
|
|
|
return inner_translate_exc2
|
|
|
|
return inner_translate_exc1
|
|
|
|
|
|
@translate_exc(from_exc=OSError, to_exc=NotImplementedError)
|
|
def is_leader():
|
|
"""Does the current unit hold the juju leadership
|
|
|
|
Uses juju to determine whether the current unit is the leader of its peers
|
|
"""
|
|
cmd = ['is-leader', '--format=json']
|
|
return json.loads(subprocess.check_output(cmd).decode('UTF-8'))
|
|
|
|
|
|
@translate_exc(from_exc=OSError, to_exc=NotImplementedError)
|
|
def leader_get(attribute=None):
|
|
"""Juju leader get value(s)"""
|
|
cmd = ['leader-get', '--format=json'] + [attribute or '-']
|
|
return json.loads(subprocess.check_output(cmd).decode('UTF-8'))
|
|
|
|
|
|
@translate_exc(from_exc=OSError, to_exc=NotImplementedError)
|
|
def leader_set(settings=None, **kwargs):
|
|
"""Juju leader set value(s)"""
|
|
# Don't log secrets.
|
|
# log("Juju leader-set '%s'" % (settings), level=DEBUG)
|
|
cmd = ['leader-set']
|
|
settings = settings or {}
|
|
settings.update(kwargs)
|
|
for k, v in settings.items():
|
|
if v is None:
|
|
cmd.append('{}='.format(k))
|
|
else:
|
|
cmd.append('{}={}'.format(k, v))
|
|
subprocess.check_call(cmd)
|
|
|
|
|
|
@translate_exc(from_exc=OSError, to_exc=NotImplementedError)
|
|
def payload_register(ptype, klass, pid):
|
|
""" is used while a hook is running to let Juju know that a
|
|
payload has been started."""
|
|
cmd = ['payload-register']
|
|
for x in [ptype, klass, pid]:
|
|
cmd.append(x)
|
|
subprocess.check_call(cmd)
|
|
|
|
|
|
@translate_exc(from_exc=OSError, to_exc=NotImplementedError)
|
|
def payload_unregister(klass, pid):
|
|
""" is used while a hook is running to let Juju know
|
|
that a payload has been manually stopped. The <class> and <id> provided
|
|
must match a payload that has been previously registered with juju using
|
|
payload-register."""
|
|
cmd = ['payload-unregister']
|
|
for x in [klass, pid]:
|
|
cmd.append(x)
|
|
subprocess.check_call(cmd)
|
|
|
|
|
|
@translate_exc(from_exc=OSError, to_exc=NotImplementedError)
|
|
def payload_status_set(klass, pid, status):
|
|
"""is used to update the current status of a registered payload.
|
|
The <class> and <id> provided must match a payload that has been previously
|
|
registered with juju using payload-register. The <status> must be one of the
|
|
follow: starting, started, stopping, stopped"""
|
|
cmd = ['payload-status-set']
|
|
for x in [klass, pid, status]:
|
|
cmd.append(x)
|
|
subprocess.check_call(cmd)
|
|
|
|
|
|
@cached
|
|
def juju_version():
|
|
"""Full version string (eg. '1.23.3.1-trusty-amd64')"""
|
|
# Per https://bugs.launchpad.net/juju-core/+bug/1455368/comments/1
|
|
jujud = glob.glob('/var/lib/juju/tools/machine-*/jujud')[0]
|
|
return subprocess.check_output([jujud, 'version'],
|
|
universal_newlines=True).strip()
|
|
|
|
|
|
@cached
|
|
def has_juju_version(minimum_version):
|
|
"""Return True if the Juju version is at least the provided version"""
|
|
return LooseVersion(juju_version()) >= LooseVersion(minimum_version)
|
|
|
|
|
|
_atexit = []
|
|
_atstart = []
|
|
|
|
|
|
def atstart(callback, *args, **kwargs):
|
|
'''Schedule a callback to run before the main hook.
|
|
|
|
Callbacks are run in the order they were added.
|
|
|
|
This is useful for modules and classes to perform initialization
|
|
and inject behavior. In particular:
|
|
|
|
- Run common code before all of your hooks, such as logging
|
|
the hook name or interesting relation data.
|
|
- Defer object or module initialization that requires a hook
|
|
context until we know there actually is a hook context,
|
|
making testing easier.
|
|
- Rather than requiring charm authors to include boilerplate to
|
|
invoke your helper's behavior, have it run automatically if
|
|
your object is instantiated or module imported.
|
|
|
|
This is not at all useful after your hook framework as been launched.
|
|
'''
|
|
global _atstart
|
|
_atstart.append((callback, args, kwargs))
|
|
|
|
|
|
def atexit(callback, *args, **kwargs):
|
|
'''Schedule a callback to run on successful hook completion.
|
|
|
|
Callbacks are run in the reverse order that they were added.'''
|
|
_atexit.append((callback, args, kwargs))
|
|
|
|
|
|
def _run_atstart():
|
|
'''Hook frameworks must invoke this before running the main hook body.'''
|
|
global _atstart
|
|
for callback, args, kwargs in _atstart:
|
|
callback(*args, **kwargs)
|
|
del _atstart[:]
|
|
|
|
|
|
def _run_atexit():
|
|
'''Hook frameworks must invoke this after the main hook body has
|
|
successfully completed. Do not invoke it if the hook fails.'''
|
|
global _atexit
|
|
for callback, args, kwargs in reversed(_atexit):
|
|
callback(*args, **kwargs)
|
|
del _atexit[:]
|