deb-heat/heat/api/aws/utils.py
liu-sheng 5541f43903 Use None instead of mutables in method params defaults
Mutables in the method params defaults might cause errors and
that's why it's anti-pattern in most of the cases and should be
removed.

Change-Id: I8bc284f12ce72082a0482410ec2c20c2fc087a4b
Closes-Bug: #1327473
2014-07-02 16:33:12 +08:00

117 lines
3.5 KiB
Python

#
# 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.
'''
Helper utilities related to the AWS API implementations
'''
import itertools
import re
from heat.api.aws import exception
from heat.openstack.common.gettextutils import _
from heat.openstack.common import log as logging
LOG = logging.getLogger(__name__)
def format_response(action, response):
"""
Format response from engine into API format
"""
return {'%sResponse' % action: {'%sResult' % action: response}}
def extract_param_pairs(params, prefix='', keyname='', valuename=''):
"""
Extract a dictionary of user input parameters, from AWS style
parameter-pair encoded list
In the AWS API list items appear as two key-value
pairs (passed as query parameters) with keys of the form below:
Prefix.member.1.keyname=somekey
Prefix.member.1.keyvalue=somevalue
Prefix.member.2.keyname=anotherkey
Prefix.member.2.keyvalue=somevalue
We reformat this into a dict here to match the heat
engine API expected format
"""
plist = extract_param_list(params, prefix)
kvs = [(p[keyname], p[valuename]) for p in plist
if keyname in p and valuename in p]
return dict(kvs)
def extract_param_list(params, prefix=''):
"""
Extract a list-of-dicts based on parameters containing AWS style list
MetricData.member.1.MetricName=buffers
MetricData.member.1.Unit=Bytes
MetricData.member.1.Value=231434333
MetricData.member.2.MetricName=buffers2
MetricData.member.2.Unit=Bytes
MetricData.member.2.Value=12345
This can be extracted by passing prefix=MetricData, resulting in a
list containing two dicts
"""
key_re = re.compile(r"%s\.member\.([0-9]+)\.(.*)" % (prefix))
def get_param_data(params):
for param_name, value in params.items():
match = key_re.match(param_name)
if match:
try:
index = int(match.group(1))
except ValueError:
pass
else:
key = match.group(2)
yield (index, (key, value))
# Sort and group by index
key_func = lambda d: d[0]
data = sorted(get_param_data(params), key=key_func)
members = itertools.groupby(data, key_func)
return [dict(kv for di, kv in m) for mi, m in members]
def get_param_value(params, key):
"""
Helper function, looks up an expected parameter in a parsed
params dict and returns the result. If params does not contain
the requested key we raise an exception of the appropriate type
"""
try:
return params[key]
except KeyError:
LOG.error(_("Request does not contain %s parameter!") % key)
raise exception.HeatMissingParameterError(key)
def reformat_dict_keys(keymap=None, inputdict=None):
'''
Utility function for mapping one dict format to another
'''
keymap = keymap or {}
inputdict = inputdict or {}
return dict([(outk, inputdict[ink]) for ink, outk in keymap.items()
if ink in inputdict])