# Copyright 2010 Jacob Kaplan-Moss
# Copyright 2011 OpenStack Foundation
# 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.
"""
Base utilities to build API operation managers and objects on top of.
"""
import abc
import contextlib
import copy
import hashlib
import inspect
import os
import threading
from oslo_utils import strutils
from requests import Response
import six
from novaclient import exceptions
from novaclient import utils
def getid(obj):
"""Get object's ID or object.
Abstracts the common pattern of allowing both an object or an object's ID
as a parameter when dealing with relationships.
"""
try:
return obj.id
except AttributeError:
return obj
# TODO(aababilov): call run_hooks() in HookableMixin's child classes
class HookableMixin(object):
"""Mixin so classes can register and run hooks."""
_hooks_map = {}
@classmethod
def add_hook(cls, hook_type, hook_func):
"""Add a new hook of specified type.
:param cls: class that registers hooks
:param hook_type: hook type, e.g., '__pre_parse_args__'
:param hook_func: hook function
"""
if hook_type not in cls._hooks_map:
cls._hooks_map[hook_type] = []
cls._hooks_map[hook_type].append(hook_func)
@classmethod
def run_hooks(cls, hook_type, *args, **kwargs):
"""Run all hooks of specified type.
:param cls: class that registers hooks
:param hook_type: hook type, e.g., '__pre_parse_args__'
:param args: args to be passed to every hook function
:param kwargs: kwargs to be passed to every hook function
"""
hook_funcs = cls._hooks_map.get(hook_type) or []
for hook_func in hook_funcs:
hook_func(*args, **kwargs)
class RequestIdMixin(object):
"""Wrapper class to expose x-openstack-request-id to the caller.
"""
def request_ids_setup(self):
self.x_openstack_request_ids = []
@property
def request_ids(self):
return self.x_openstack_request_ids
def append_request_ids(self, resp):
"""Add request_ids as an attribute to the object
:param resp: Response object or list of Response objects
"""
if isinstance(resp, list):
# Add list of request_ids if response is of type list.
for resp_obj in resp:
self._append_request_id(resp_obj)
elif resp is not None:
# Add request_ids if response contains single object.
self._append_request_id(resp)
def _append_request_id(self, resp):
if isinstance(resp, Response):
# Extract 'x-openstack-request-id' from headers if
# response is a Response object.
request_id = (resp.headers.get('x-openstack-request-id') or
resp.headers.get('x-compute-request-id'))
else:
# If resp is of type string or None.
request_id = resp
if request_id not in self.x_openstack_request_ids:
self.x_openstack_request_ids.append(request_id)
class Resource(RequestIdMixin):
"""Base class for OpenStack resources (tenant, user, etc.).
This is pretty much just a bag for attributes.
"""
HUMAN_ID = False
NAME_ATTR = 'name'
def __init__(self, manager, info, loaded=False, resp=None):
"""Populate and bind to a manager.
:param manager: BaseManager object
:param info: dictionary representing resource attributes
:param loaded: prevent lazy-loading if set to True
:param resp: Response or list of Response objects
"""
self.manager = manager
self._info = info
self._add_details(info)
self._loaded = loaded
self.request_ids_setup()
self.append_request_ids(resp)
def __repr__(self):
reprkeys = sorted(k
for k in self.__dict__.keys()
if k[0] != '_' and
k not in ['manager', 'x_openstack_request_ids'])
info = ", ".join("%s=%s" % (k, getattr(self, k)) for k in reprkeys)
return "<%s %s>" % (self.__class__.__name__, info)
@property
def human_id(self):
"""Human-readable ID which can be used for bash completion.
"""
if self.HUMAN_ID:
name = getattr(self, self.NAME_ATTR, None)
if name is not None:
return strutils.to_slug(name)
return None
def _add_details(self, info):
for (k, v) in six.iteritems(info):
try:
setattr(self, k, v)
self._info[k] = v
except AttributeError:
# In this case we already defined the attribute on the class
pass
def __getattr__(self, k):
if k not in self.__dict__:
# NOTE(bcwaldon): disallow lazy-loading if already loaded once
if not self.is_loaded():
self.get()
return self.__getattr__(k)
raise AttributeError(k)
else:
return self.__dict__[k]
def get(self):
"""Support for lazy loading details.
Some clients, such as novaclient have the option to lazy load the
details, details which can be loaded with this function.
"""
# set_loaded() first ... so if we have to bail, we know we tried.
self.set_loaded(True)
if not hasattr(self.manager, 'get'):
return
new = self.manager.get(self.id)
if new:
self._add_details(new._info)
# The 'request_ids' attribute has been added,
# so store the request id to it instead of _info
self.append_request_ids(new.request_ids)
def __eq__(self, other):
if not isinstance(other, Resource):
return NotImplemented
# two resources of different types are not equal
if not isinstance(other, self.__class__):
return False
if hasattr(self, 'id') and hasattr(other, 'id'):
return self.id == other.id
return self._info == other._info
def is_loaded(self):
return self._loaded
def set_loaded(self, val):
self._loaded = val
def to_dict(self):
return copy.deepcopy(self._info)
class Manager(HookableMixin):
"""Manager for API service.
Managers interact with a particular type of API (servers, flavors, images,
etc.) and provide CRUD operations for them.
"""
resource_class = None
cache_lock = threading.RLock()
def __init__(self, api):
self.api = api
@property
def client(self):
return self.api.client
@property
def api_version(self):
return self.api.api_version
def _list(self, url, response_key, obj_class=None, body=None):
if body:
resp, body = self.api.client.post(url, body=body)
else:
resp, body = self.api.client.get(url)
if obj_class is None:
obj_class = self.resource_class
data = body[response_key]
# NOTE(ja): keystone returns values as list as {'values': [ ... ]}
# unlike other services which just return the list...
if isinstance(data, dict):
try:
data = data['values']
except KeyError:
pass
with self.completion_cache('human_id', obj_class, mode="w"):
with self.completion_cache('uuid', obj_class, mode="w"):
items = [obj_class(self, res, loaded=True)
for res in data if res]
return ListWithMeta(items, resp)
@contextlib.contextmanager
def alternate_service_type(self, default, allowed_types=()):
original_service_type = self.api.client.service_type
if original_service_type in allowed_types:
yield
else:
self.api.client.service_type = default
try:
yield
finally:
self.api.client.service_type = original_service_type
@contextlib.contextmanager
def completion_cache(self, cache_type, obj_class, mode):
"""The completion cache for bash autocompletion.
The completion cache store items that can be used for bash
autocompletion, like UUIDs or human-friendly IDs.
A resource listing will clear and repopulate the cache.
A resource create will append to the cache.
Delete is not handled because listings are assumed to be performed
often enough to keep the cache reasonably up-to-date.
"""
# NOTE(wryan): This lock protects read and write access to the
# completion caches
with self.cache_lock:
base_dir = utils.env('NOVACLIENT_UUID_CACHE_DIR',
default="~/.novaclient")
# NOTE(sirp): Keep separate UUID caches for each username +
# endpoint pair
username = utils.env('OS_USERNAME', 'NOVA_USERNAME')
url = utils.env('OS_URL', 'NOVA_URL')
uniqifier = hashlib.md5(username.encode('utf-8') +
url.encode('utf-8')).hexdigest()
cache_dir = os.path.expanduser(os.path.join(base_dir, uniqifier))
try:
os.makedirs(cache_dir, 0o755)
except OSError:
# NOTE(kiall): This is typically either permission denied while
# attempting to create the directory, or the
# directory already exists. Either way, don't
# fail.
pass
resource = obj_class.__name__.lower()
filename = "%s-%s-cache" % (resource, cache_type.replace('_', '-'))
path = os.path.join(cache_dir, filename)
cache_attr = "_%s_cache" % cache_type
try:
setattr(self, cache_attr, open(path, mode))
except IOError:
# NOTE(kiall): This is typically a permission denied while
# attempting to write the cache file.
pass
try:
yield
finally:
cache = getattr(self, cache_attr, None)
if cache:
cache.close()
delattr(self, cache_attr)
def write_to_completion_cache(self, cache_type, val):
cache = getattr(self, "_%s_cache" % cache_type, None)
if cache:
cache.write("%s\n" % val)
def _get(self, url, response_key):
resp, body = self.api.client.get(url)
return self.resource_class(self, body[response_key], loaded=True,
resp=resp)
def _create(self, url, body, response_key, return_raw=False, **kwargs):
self.run_hooks('modify_body_for_create', body, **kwargs)
resp, body = self.api.client.post(url, body=body)
if return_raw:
return self.convert_into_with_meta(body[response_key], resp)
with self.completion_cache('human_id', self.resource_class, mode="a"):
with self.completion_cache('uuid', self.resource_class, mode="a"):
return self.resource_class(self, body[response_key], resp=resp)
def _delete(self, url):
resp, body = self.api.client.delete(url)
return self.convert_into_with_meta(body, resp)
def _update(self, url, body, response_key=None, **kwargs):
self.run_hooks('modify_body_for_update', body, **kwargs)
resp, body = self.api.client.put(url, body=body)
if body:
if response_key:
return self.resource_class(self, body[response_key], resp=resp)
else:
return self.resource_class(self, body, resp=resp)
else:
return StrWithMeta(body, resp)
def convert_into_with_meta(self, item, resp):
if isinstance(item, six.string_types):
if six.PY2 and isinstance(item, six.text_type):
return UnicodeWithMeta(item, resp)
else:
return StrWithMeta(item, resp)
elif isinstance(item, six.binary_type):
return BytesWithMeta(item, resp)
elif isinstance(item, list):
return ListWithMeta(item, resp)
elif isinstance(item, tuple):
return TupleWithMeta(item, resp)
elif item is None:
return TupleWithMeta((), resp)
else:
return DictWithMeta(item, resp)
@six.add_metaclass(abc.ABCMeta)
class ManagerWithFind(Manager):
"""Like a `Manager`, but with additional `find()`/`findall()` methods."""
@abc.abstractmethod
def list(self):
pass
def find(self, **kwargs):
"""Find a single item with attributes matching ``**kwargs``."""
matches = self.findall(**kwargs)
num_matches = len(matches)
if num_matches == 0:
msg = "No %s matching %s." % (self.resource_class.__name__, kwargs)
raise exceptions.NotFound(404, msg)
elif num_matches > 1:
raise exceptions.NoUniqueMatch
else:
matches[0].append_request_ids(matches.request_ids)
return matches[0]
def findall(self, **kwargs):
"""Find all items with attributes matching ``**kwargs``."""
found = ListWithMeta([], None)
searches = kwargs.items()
detailed = True
list_kwargs = {}
list_argspec = inspect.getargspec(self.list)
if 'detailed' in list_argspec.args:
detailed = ("human_id" not in kwargs and
"name" not in kwargs and
"display_name" not in kwargs)
list_kwargs['detailed'] = detailed
if 'is_public' in list_argspec.args and 'is_public' in kwargs:
is_public = kwargs['is_public']
list_kwargs['is_public'] = is_public
if is_public is None:
tmp_kwargs = kwargs.copy()
del tmp_kwargs['is_public']
searches = tmp_kwargs.items()
if 'search_opts' in list_argspec.args:
# pass search_opts in to do server side based filtering.
# TODO(jogo) not all search_opts support regex, find way to
# identify when to use regex and when to use string matching.
# volumes does not support regex while servers does. So when
# doing findall on servers some client side filtering is still
# needed.
if "human_id" in kwargs:
list_kwargs['search_opts'] = {"name": kwargs["human_id"]}
elif "name" in kwargs:
list_kwargs['search_opts'] = {"name": kwargs["name"]}
elif "display_name" in kwargs:
list_kwargs['search_opts'] = {"name": kwargs["display_name"]}
if "all_tenants" in kwargs:
all_tenants = kwargs['all_tenants']
list_kwargs['search_opts']['all_tenants'] = all_tenants
searches = [(k, v) for k, v in searches if k != 'all_tenants']
if "deleted" in kwargs:
deleted = kwargs['deleted']
list_kwargs['search_opts']['deleted'] = deleted
searches = [(k, v) for k, v in searches if k != 'deleted']
listing = self.list(**list_kwargs)
found.append_request_ids(listing.request_ids)
for obj in listing:
try:
if all(getattr(obj, attr) == value
for (attr, value) in searches):
if detailed:
found.append(obj)
else:
detail = self.get(obj.id)
found.append(detail)
found.append_request_ids(detail.request_ids)
except AttributeError:
continue
return found
class BootingManagerWithFind(ManagerWithFind):
"""Like a `ManagerWithFind`, but has the ability to boot servers."""
def _parse_block_device_mapping(self, block_device_mapping):
"""Parses legacy block device mapping."""
# FIXME(andreykurilin): make it work with block device mapping v2
bdm = []
for device_name, mapping in six.iteritems(block_device_mapping):
#
# The mapping is in the format:
# <id>:[<type>]:[<size(GB)>]:[<delete_on_terminate>]
#
bdm_dict = {'device_name': device_name}
mapping_parts = mapping.split(':')
source_id = mapping_parts[0]
if len(mapping_parts) == 1:
bdm_dict['volume_id'] = source_id
elif len(mapping_parts) > 1:
source_type = mapping_parts[1]
if source_type.startswith('snap'):
bdm_dict['snapshot_id'] = source_id
else:
bdm_dict['volume_id'] = source_id
if len(mapping_parts) > 2 and mapping_parts[2]:
bdm_dict['volume_size'] = str(int(mapping_parts[2]))
if len(mapping_parts) > 3:
bdm_dict['delete_on_termination'] = mapping_parts[3]
bdm.append(bdm_dict)
return bdm
class ListWithMeta(list, RequestIdMixin):
def __init__(self, values, resp):
super(ListWithMeta, self).__init__(values)
self.request_ids_setup()
self.append_request_ids(resp)
class DictWithMeta(dict, RequestIdMixin):
def __init__(self, values, resp):
super(DictWithMeta, self).__init__(values)
self.request_ids_setup()
self.append_request_ids(resp)
class TupleWithMeta(tuple, RequestIdMixin):
def __new__(cls, values, resp):
return super(TupleWithMeta, cls).__new__(cls, values)
def __init__(self, values, resp):
self.request_ids_setup()
self.append_request_ids(resp)
class StrWithMeta(str, RequestIdMixin):
def __new__(cls, value, resp):
return super(StrWithMeta, cls).__new__(cls, value)
def __init__(self, values, resp):
self.request_ids_setup()
self.append_request_ids(resp)
class BytesWithMeta(six.binary_type, RequestIdMixin):
def __new__(cls, value, resp):
return super(BytesWithMeta, cls).__new__(cls, value)
def __init__(self, values, resp):
self.request_ids_setup()
self.append_request_ids(resp)
if six.PY2:
class UnicodeWithMeta(six.text_type, RequestIdMixin):
def __new__(cls, value, resp):
return super(UnicodeWithMeta, cls).__new__(cls, value)
def __init__(self, values, resp):
self.request_ids_setup()
self.append_request_ids(resp)