blazar/blazar/utils/plugins.py

73 lines
2.7 KiB
Python

# Copyright (c) 2017 NTT.
#
# 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.
from oslo_serialization import jsonutils
import six
from blazar.manager import exceptions as manager_ex
def convert_requirements(requirements):
"""Convert the requirements to an array of strings
Convert the requirements to an array of strings.
["key op value", "key op value", ...]
"""
# TODO(frossigneux) Support the "or" operator
# Convert text to json
if isinstance(requirements, six.string_types):
try:
requirements = jsonutils.loads(requirements)
except ValueError:
raise manager_ex.MalformedRequirements(rqrms=requirements)
# Requirement list looks like ['<', '$ram', '1024']
if _requirements_with_three_elements(requirements):
result = []
if requirements[0] == '=':
requirements[0] = '=='
string = (requirements[1][1:] + " " + requirements[0] + " " +
requirements[2])
result.append(string)
return result
# Remove the 'and' element at the head of the requirement list
elif _requirements_with_and_keyword(requirements):
return [convert_requirements(x)[0] for x in requirements[1:]]
# Empty requirement list0
elif isinstance(requirements, list) and not requirements:
return requirements
else:
raise manager_ex.MalformedRequirements(rqrms=requirements)
def _requirements_with_three_elements(requirements):
"""Return true if requirement list looks like ['<', '$ram', '1024']."""
return (isinstance(requirements, list) and
len(requirements) == 3 and
isinstance(requirements[0], six.string_types) and
isinstance(requirements[1], six.string_types) and
isinstance(requirements[2], six.string_types) and
requirements[0] in ['==', '=', '!=', '>=', '<=', '>', '<'] and
len(requirements[1]) > 1 and requirements[1][0] == '$' and
len(requirements[2]) > 0)
def _requirements_with_and_keyword(requirements):
return (len(requirements) > 1 and
isinstance(requirements[0], six.string_types) and
requirements[0] == 'and' and
all(convert_requirements(x) for x in requirements[1:]))