summaryrefslogtreecommitdiffstats
path: root/policyhandler/policy_utils.py
blob: c2a8b07b78a713c7901a2166584206a75f5730ae (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
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