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| 1 | +# Copyright 2021 The Kubernetes Authors. |
| 2 | +# |
| 3 | +# Licensed under the Apache License, Version 2.0 (the "License"); |
| 4 | +# you may not use this file except in compliance with the License. |
| 5 | +# You may obtain a copy of the License at |
| 6 | +# |
| 7 | +# http://www.apache.org/licenses/LICENSE-2.0 |
| 8 | +# |
| 9 | +# Unless required by applicable law or agreed to in writing, software |
| 10 | +# distributed under the License is distributed on an "AS IS" BASIS, |
| 11 | +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 12 | +# See the License for the specific language governing permissions and |
| 13 | +# limitations under the License. |
| 14 | + |
| 15 | +import logging |
| 16 | +from datetime import datetime |
| 17 | + |
| 18 | +from kubernetes_asyncio import client |
| 19 | +from kubernetes_asyncio.client.rest import ApiException |
| 20 | + |
| 21 | +from ..leaderelectionrecord import LeaderElectionRecord |
| 22 | + |
| 23 | +logging.basicConfig(level=logging.INFO) |
| 24 | + |
| 25 | + |
| 26 | +class LeaseLock: |
| 27 | + def __init__(self, name, namespace, identity, api_client): |
| 28 | + """ |
| 29 | + :param name: name of the lock |
| 30 | + :param namespace: namespace |
| 31 | + :param identity: A unique identifier that the candidate is using |
| 32 | + """ |
| 33 | + self.api_instance = client.CoordinationV1Api(api_client=api_client) |
| 34 | + |
| 35 | + # lease resource identity and reference |
| 36 | + self.name = name |
| 37 | + self.namespace = namespace |
| 38 | + self.lease_reference = None |
| 39 | + |
| 40 | + # identity of this candidate |
| 41 | + self.identity = str(identity) |
| 42 | + |
| 43 | + # get returns the election record from a Lease Annotation |
| 44 | + async def get(self, name, namespace): |
| 45 | + """ |
| 46 | + :param name: Name of the lease object information to get |
| 47 | + :param namespace: Namespace in which the lease object is to be searched |
| 48 | + :return: 'True, election record' if object found else 'False, exception response' |
| 49 | + """ |
| 50 | + try: |
| 51 | + lease = await self.api_instance.read_namespaced_lease(name, namespace) |
| 52 | + except ApiException as e: |
| 53 | + return False, e |
| 54 | + else: |
| 55 | + self.lease_reference = lease |
| 56 | + return True, self.election_record(lease) |
| 57 | + |
| 58 | + async def create(self, name, namespace, election_record): |
| 59 | + """ |
| 60 | + :param electionRecord: Annotation string |
| 61 | + :param name: Name of the lease object to be created |
| 62 | + :param namespace: Namespace in which the lease object is to be created |
| 63 | + :return: 'True' if object is created else 'False' if failed |
| 64 | + """ |
| 65 | + body = client.V1Lease( |
| 66 | + metadata={"name": name}, spec=self.update_lease(election_record) |
| 67 | + ) |
| 68 | + |
| 69 | + try: |
| 70 | + await self.api_instance.create_namespaced_lease( |
| 71 | + namespace, body, pretty=True |
| 72 | + ) |
| 73 | + return True |
| 74 | + except ApiException as e: |
| 75 | + logging.info("Failed to create lock as {}".format(e)) |
| 76 | + return False |
| 77 | + |
| 78 | + async def update(self, name, namespace, updated_record): |
| 79 | + """ |
| 80 | + :param name: name of the lock to be updated |
| 81 | + :param namespace: namespace the lock is in |
| 82 | + :param updated_record: the updated election record |
| 83 | + :return: True if update is successful False if it fails |
| 84 | + """ |
| 85 | + try: |
| 86 | + # update the Lease from the updated record |
| 87 | + self.lease_reference.spec = self.update_lease( |
| 88 | + updated_record, self.lease_reference.spec |
| 89 | + ) |
| 90 | + |
| 91 | + await self.api_instance.replace_namespaced_lease( |
| 92 | + name=name, namespace=namespace, body=self.lease_reference |
| 93 | + ) |
| 94 | + return True |
| 95 | + except ApiException as e: |
| 96 | + logging.info("Failed to update lock as {}".format(e)) |
| 97 | + return False |
| 98 | + |
| 99 | + def update_lease(self, leader_election_record, current_spec=None): |
| 100 | + # existing or new lease? |
| 101 | + spec = current_spec if current_spec else client.V1LeaseSpec() |
| 102 | + |
| 103 | + # lease configuration |
| 104 | + spec.holder_identity = leader_election_record.holder_identity |
| 105 | + spec.lease_duration_seconds = int(leader_election_record.lease_duration) |
| 106 | + spec.acquire_time = self.time_str_to_iso(leader_election_record.acquire_time) |
| 107 | + spec.renew_time = self.time_str_to_iso(leader_election_record.renew_time) |
| 108 | + |
| 109 | + return spec |
| 110 | + |
| 111 | + def election_record(self, lease): |
| 112 | + """ |
| 113 | + Get leader election record from Lease spec. |
| 114 | + """ |
| 115 | + leader_election_record = LeaderElectionRecord(None, None, None, None) |
| 116 | + |
| 117 | + if not lease.spec: |
| 118 | + return leader_election_record |
| 119 | + |
| 120 | + if lease.spec.holder_identity: |
| 121 | + leader_election_record.holder_identity = lease.spec.holder_identity |
| 122 | + if lease.spec.lease_duration_seconds: |
| 123 | + leader_election_record.lease_duration = str( |
| 124 | + lease.spec.lease_duration_seconds |
| 125 | + ) |
| 126 | + if lease.spec.acquire_time: |
| 127 | + leader_election_record.acquire_time = str( |
| 128 | + datetime.replace(lease.spec.acquire_time, tzinfo=None) |
| 129 | + ) |
| 130 | + if lease.spec.renew_time: |
| 131 | + leader_election_record.renew_time = str( |
| 132 | + datetime.replace(lease.spec.renew_time, tzinfo=None) |
| 133 | + ) |
| 134 | + |
| 135 | + return leader_election_record |
| 136 | + |
| 137 | + # conversion between kubernetes ISO formatted time and elector record time |
| 138 | + def time_str_to_iso(self, str_time): |
| 139 | + formats = ["%Y-%m-%d %H:%M:%S.%f%z", "%Y-%m-%d %H:%M:%S.%f"] |
| 140 | + for fmt in formats: |
| 141 | + try: |
| 142 | + return datetime.strptime(str_time, fmt).isoformat() + "Z" |
| 143 | + except ValueError: |
| 144 | + pass |
| 145 | + logging.error("Failed to parse time string: {}".format(str_time)) |
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