# Copyright 2010 Jacob Kaplan-Moss
# Copyright (c) 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 hashlib
import os
import six
from cinderclient import exceptions
from cinderclient.openstack.common.apiclient import base as common_base
from cinderclient import utils
Resource = common_base.Resource
def getid(obj):
"""
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
class Manager(utils.HookableMixin):
"""
Managers interact with a particular type of API (servers, flavors, images,
etc.) and provide CRUD operations for them.
"""
resource_class = None
def __init__(self, api):
self.api = api
def _list(self, url, response_key, obj_class=None, body=None,
limit=None, items=None):
resp = None
if items is None:
items = []
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_new = [obj_class(self, res, loaded=True)
for res in data if res]
if limit:
limit = int(limit)
margin = limit - len(items)
if margin <= len(items_new):
# If the limit is reached, return the items.
items = items + items_new[:margin]
return items
else:
items = items + items_new
else:
items = items + items_new
# It is possible that the length of the list we request is longer
# than osapi_max_limit, so we have to retrieve multiple times to
# get the complete list.
next = None
if 'volumes_links' in body:
volumes_links = body['volumes_links']
if volumes_links:
for volumes_link in volumes_links:
if 'rel' in volumes_link and 'next' == volumes_link['rel']:
next = volumes_link['href']
break
if next:
# As long as the 'next' link is not empty, keep requesting it
# till there is no more items.
items = self._list(next, response_key, obj_class, None,
limit, items)
return items
@contextlib.contextmanager
def completion_cache(self, cache_type, obj_class, mode):
"""
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.
"""
base_dir = utils.env('CINDERCLIENT_UUID_CACHE_DIR',
default="~/.cinderclient")
# NOTE(sirp): Keep separate UUID caches for each username + endpoint
# pair
username = utils.env('OS_USERNAME', 'CINDER_USERNAME')
url = utils.env('OS_URL', 'CINDER_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=None):
resp, body = self.api.client.get(url)
if response_key:
return self.resource_class(self, body[response_key], loaded=True)
else:
return self.resource_class(self, body, loaded=True)
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 body[response_key]
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])
def _delete(self, url):
resp, body = self.api.client.delete(url)
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 response_key:
return self.resource_class(self, body[response_key], loaded=True)
return body
class ManagerWithFind(six.with_metaclass(abc.ABCMeta, 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``.
This isn't very efficient: it loads the entire list then filters on
the Python side.
"""
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:
return matches[0]
def findall(self, **kwargs):
"""
Find all items with attributes matching ``**kwargs``.
This isn't very efficient: it loads the entire list then filters on
the Python side.
"""
found = []
searches = list(kwargs.items())
# Want to search for all tenants here so that when attempting to delete
# that a user like admin doesn't get a failure when trying to delete
# another tenant's volume by name.
for obj in self.list(search_opts={'all_tenants': 1}):
try:
if all(getattr(obj, attr) == value
for (attr, value) in searches):
found.append(obj)
except AttributeError:
continue
return found