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Diffstat (limited to 'policyhandler/policy_utils.py')
-rw-r--r-- | policyhandler/policy_utils.py | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/policyhandler/policy_utils.py b/policyhandler/policy_utils.py new file mode 100644 index 0000000..c2a8b07 --- /dev/null +++ b/policyhandler/policy_utils.py @@ -0,0 +1,175 @@ +# ================================================================================ +# Copyright (c) 2018 AT&T Intellectual Property. 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. +# ============LICENSE_END========================================================= +# +# ECOMP is a trademark and service mark of AT&T Intellectual Property. + +"""policy-client communicates with policy-engine thru REST API""" + +import json +import logging +import re + +from .policy_consts import (POLICY_BODY, POLICY_CONFIG, POLICY_ID, POLICY_NAME, + POLICY_VERSION) + +class PolicyUtils(object): + """policy-client utils""" + _logger = logging.getLogger("policy_handler.policy_utils") + _policy_name_ext = re.compile('[.][0-9]+[.][a-zA-Z]+$') + + @staticmethod + def extract_policy_id(policy_name): + """ policy_name = policy_id + "." + <version> + "." + <extension> + For instance, + policy_name = DCAE_alex.Config_alex_policy_number_1.3.xml + policy_id = DCAE_alex.Config_alex_policy_number_1 + policy_scope = DCAE_alex + policy_class = Config + policy_version = 3 + type = extension = xml + delimiter = "." + policy_class_delimiter = "_" + policy_name in PAP = DCAE_alex.alex_policy_number_1 + """ + if not policy_name: + return + return PolicyUtils._policy_name_ext.sub('', policy_name) + + @staticmethod + def parse_policy_config(policy): + """try parsing the config in policy.""" + if not policy: + return policy + config = policy.get(POLICY_BODY, {}).get(POLICY_CONFIG) + if config: + policy[POLICY_BODY][POLICY_CONFIG] = Utils.safe_json_parse(config) + return policy + + @staticmethod + def convert_to_policy(policy_config): + """wrap policy_config received from policy-engine with policy_id.""" + if not policy_config: + return + policy_name = policy_config.get(POLICY_NAME) + policy_version = policy_config.get(POLICY_VERSION) + if not policy_name or not policy_version: + return + policy_id = PolicyUtils.extract_policy_id(policy_name) + if not policy_id: + return + return {POLICY_ID:policy_id, POLICY_BODY:policy_config} + + @staticmethod + def select_latest_policy(policy_configs, min_version_expected=None, ignore_policy_names=None): + """For some reason, the policy-engine returns all version of the policy_configs. + DCAE-Controller is only interested in the latest version + """ + if not policy_configs: + return + latest_policy_config = {} + for policy_config in policy_configs: + policy_name = policy_config.get(POLICY_NAME) + policy_version = policy_config.get(POLICY_VERSION) + if not policy_name or not policy_version or not policy_version.isdigit(): + continue + policy_version = int(policy_version) + if min_version_expected and policy_version < min_version_expected: + continue + if ignore_policy_names and policy_name in ignore_policy_names: + continue + + if not latest_policy_config \ + or int(latest_policy_config[POLICY_VERSION]) < policy_version: + latest_policy_config = policy_config + + return PolicyUtils.parse_policy_config(PolicyUtils.convert_to_policy(latest_policy_config)) + + @staticmethod + def select_latest_policies(policy_configs): + """For some reason, the policy-engine returns all version of the policy_configs. + DCAE-Controller is only interested in the latest versions + """ + if not policy_configs: + return {} + policies = {} + for policy_config in policy_configs: + policy = PolicyUtils.convert_to_policy(policy_config) + if not policy: + continue + policy_id = policy.get(POLICY_ID) + policy_version = policy.get(POLICY_BODY, {}).get(POLICY_VERSION) + if not policy_id or not policy_version or not policy_version.isdigit(): + continue + if policy_id not in policies \ + or int(policy_version) > int(policies[policy_id][POLICY_BODY][POLICY_VERSION]): + policies[policy_id] = policy + + for policy_id in policies: + policies[policy_id] = PolicyUtils.parse_policy_config(policies[policy_id]) + + return policies + +class Utils(object): + """general purpose utils""" + _logger = logging.getLogger("policy_handler.utils") + + @staticmethod + def safe_json_parse(json_str): + """try parsing json without exception - returns the json_str back if fails""" + if not json_str: + return json_str + try: + return json.loads(json_str) + except (ValueError, TypeError) as err: + Utils._logger.warning("unexpected json error(%s): len(%s) str[:100]: (%s)", + str(err), len(json_str), str(json_str)[:100]) + return json_str + + @staticmethod + def are_the_same(body_1, body_2): + """check whether both objects are the same""" + if (body_1 and not body_2) or (not body_1 and body_2): + Utils._logger.debug("only one is empty %s != %s", body_1, body_2) + return False + + if body_1 is None and body_2 is None: + return True + + if isinstance(body_1, list) and isinstance(body_2, list): + if len(body_1) != len(body_2): + Utils._logger.debug("len %s != %s", json.dumps(body_1), json.dumps(body_2)) + return False + + for val_1, val_2 in zip(body_1, body_2): + if not Utils.are_the_same(val_1, val_2): + return False + return True + + if isinstance(body_1, dict) and isinstance(body_2, dict): + if body_1.keys() ^ body_2.keys(): + Utils._logger.debug("keys %s != %s", json.dumps(body_1), json.dumps(body_2)) + return False + + for key, val_1 in body_1.items(): + if not Utils.are_the_same(val_1, body_2[key]): + return False + return True + + # ... here when primitive values or mismatched types ... + the_same_values = (body_1 == body_2) + if not the_same_values: + Utils._logger.debug("values %s != %s", body_1, body_2) + return the_same_values |