#
# Copyright 2012 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.
"""
Base utilities to build API operation managers and objects on top of.
"""
import copy
from urllib import parse as urlparse
from watcherclient.common.apiclient import base
[docs]
def getid(obj):
"""Wrapper to get object's ID.
Abstracts the common pattern of allowing both an object or an
object's ID (UUID) as a parameter when dealing with relationships.
"""
return getattr(obj, 'id', obj)
[docs]
class Manager(object):
"""Provides CRUD operations with a particular API."""
resource_class = None
def __init__(self, api):
self.api = api
def _create(self, url, body):
resp, body = self.api.json_request('POST', url, body=body)
if body:
return self.resource_class(self, body)
def _format_body_data(self, body, response_key):
if response_key:
try:
data = body[response_key]
except KeyError:
return []
else:
data = body
if not isinstance(data, list):
data = [data]
return data
def _list_pagination(self, url, response_key=None, obj_class=None,
limit=None):
"""Retrieve a list of items.
The Watcher API is configured to return a maximum number of
items per request, (see Watcher's api.max_limit option). This
iterates over the 'next' link (pagination) in the responses,
to get the number of items specified by 'limit'. If 'limit'
is None this function will continue pagination until there are
no more values to be returned.
:param url: a partial URL, e.g. '/nodes'
:param response_key: the key to be looked up in response
dictionary, e.g. 'nodes'
:param obj_class: class for constructing the returned objects.
:param limit: maximum number of items to return. If None returns
everything.
"""
if obj_class is None:
obj_class = self.resource_class
if limit is not None:
limit = int(limit)
object_list = []
object_count = 0
limit_reached = False
while url:
resp, body = self.api.json_request('GET', url)
data = self._format_body_data(body, response_key)
for obj in data:
object_list.append(obj_class(self, obj, loaded=True))
object_count += 1
if limit and object_count >= limit:
# break the for loop
limit_reached = True
break
# break the while loop and return
if limit_reached:
break
url = body.get('next')
if url:
# NOTE(lucasagomes): We need to edit the URL to remove
# the scheme and netloc
url_parts = list(urlparse.urlparse(url))
url_parts[0] = url_parts[1] = ''
url = urlparse.urlunparse(url_parts)
return object_list
def _list(self, url, response_key=None, obj_class=None, body=None):
resp, body = self.api.json_request('GET', url)
if obj_class is None:
obj_class = self.resource_class
data = self._format_body_data(body, response_key)
return [obj_class(self, res, loaded=True) for res in data if res]
def _update(self, url, body, method='PATCH', response_key=None):
resp, body = self.api.json_request(method, url, body=body)
# PATCH/PUT requests may not return a body
if body:
return self.resource_class(self, body)
def _delete(self, url):
self.api.raw_request('DELETE', url)
def _start(self, url, body=None, method='POST'):
resp, body = self.api.json_request(method, url, body={})
if body:
return self.resource_class(self, body)
[docs]
class Resource(base.Resource):
"""Represents a particular instance of an object (tenant, user, etc).
This is pretty much just a bag for attributes.
"""
[docs]
def to_dict(self):
return copy.deepcopy(self._info)
