|
| 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 | +fromkubernetes.client.restimportApiException |
| 16 | +fromkubernetesimportclient |
| 17 | +from ..leaderelectionrecordimportLeaderElectionRecord |
| 18 | +fromdatetimeimportdatetime |
| 19 | +importlogging |
| 20 | +logging.basicConfig(level=logging.INFO) |
| 21 | + |
| 22 | + |
| 23 | +classLeaseLock: |
| 24 | +def__init__(self,name,namespace,identity): |
| 25 | +""" |
| 26 | + :param name: name of the lock |
| 27 | + :param namespace: namespace |
| 28 | + :param identity: A unique identifier that the candidate is using |
| 29 | + """ |
| 30 | +self.api_instance=client.CoordinationV1Api() |
| 31 | + |
| 32 | +# lease resource identity and reference |
| 33 | +self.name=name |
| 34 | +self.namespace=namespace |
| 35 | +self.lease_reference=None |
| 36 | + |
| 37 | +# identity of this candidate |
| 38 | +self.identity=str(identity) |
| 39 | + |
| 40 | +# get returns the election record from a Lease Annotation |
| 41 | +defget(self,name,namespace): |
| 42 | +""" |
| 43 | + :param name: Name of the lease object information to get |
| 44 | + :param namespace: Namespace in which the lease object is to be searched |
| 45 | + :return: 'True, election record' if object found else 'False, exception response' |
| 46 | + """ |
| 47 | +try: |
| 48 | +lease=self.api_instance.read_namespaced_lease(name,namespace) |
| 49 | + |
| 50 | +exceptApiExceptionase: |
| 51 | +returnFalse,e |
| 52 | +else: |
| 53 | +self.lease_reference=lease |
| 54 | +returnTrue,self.election_record(lease) |
| 55 | + |
| 56 | +defcreate(self,name,namespace,election_record): |
| 57 | +""" |
| 58 | + :param electionRecord: Annotation string |
| 59 | + :param name: Name of the lease object to be created |
| 60 | + :param namespace: Namespace in which the lease object is to be created |
| 61 | + :return: 'True' if object is created else 'False' if failed |
| 62 | + """ |
| 63 | +body=client.V1Lease(metadata={"name":name}, |
| 64 | +spec=self.update_lease(election_record)) |
| 65 | + |
| 66 | +try: |
| 67 | +_=self.api_instance.create_namespaced_lease(namespace,body,pretty=True) |
| 68 | +returnTrue |
| 69 | +exceptApiExceptionase: |
| 70 | +logging.info("Failed to create lock as {}".format(e)) |
| 71 | +returnFalse |
| 72 | + |
| 73 | +defupdate(self,name,namespace,updated_record): |
| 74 | +""" |
| 75 | + :param name: name of the lock to be updated |
| 76 | + :param namespace: namespace the lock is in |
| 77 | + :param updated_record: the updated election record |
| 78 | + :return: True if update is successful False if it fails |
| 79 | + """ |
| 80 | +try: |
| 81 | +# update the Lease from the updated record |
| 82 | +self.lease_reference.spec=self.update_lease(updated_record, |
| 83 | +self.lease_reference.spec) |
| 84 | + |
| 85 | +_=self.api_instance.replace_namespaced_lease(name=name,namespace=namespace, |
| 86 | +body=self.lease_reference) |
| 87 | +returnTrue |
| 88 | +exceptApiExceptionase: |
| 89 | +logging.info("Failed to update lock as {}".format(e)) |
| 90 | +returnFalse |
| 91 | + |
| 92 | +defupdate_lease(self,leader_election_record,current_spec=None): |
| 93 | +# existing or new lease? |
| 94 | +spec=current_specifcurrent_specelseclient.V1LeaseSpec() |
| 95 | + |
| 96 | +# lease configuration |
| 97 | +spec.holder_identity=leader_election_record.holder_identity |
| 98 | +spec.lease_duration_seconds=int(leader_election_record.lease_duration) |
| 99 | +spec.acquire_time=self.time_str_to_iso(leader_election_record.acquire_time) |
| 100 | +spec.renew_time=self.time_str_to_iso(leader_election_record.renew_time) |
| 101 | + |
| 102 | +returnspec |
| 103 | + |
| 104 | +defelection_record(self,lease): |
| 105 | +""" |
| 106 | + Get leader election record from Lease spec. |
| 107 | + """ |
| 108 | +leader_election_record=LeaderElectionRecord(None,None,None,None) |
| 109 | + |
| 110 | +iflease.specandlease.spec.holder_identity: |
| 111 | +leader_election_record.holder_identity=lease.spec.holder_identity |
| 112 | +iflease.specandlease.spec.lease_duration_seconds: |
| 113 | +leader_election_record.lease_duration=str(lease.spec.lease_duration_seconds) |
| 114 | +iflease.specandlease.spec.acquire_time: |
| 115 | +leader_election_record.acquire_time=str(datetime.replace(lease.spec.acquire_time,tzinfo=None)) |
| 116 | +iflease.specandlease.spec.renew_time: |
| 117 | +leader_election_record.renew_time=str(datetime.replace(lease.spec.renew_time,tzinfo=None)) |
| 118 | + |
| 119 | +returnleader_election_record |
| 120 | + |
| 121 | +# conversion between kubernetes ISO formatted time and elector record time |
| 122 | +deftime_str_to_iso(self,str_time): |
| 123 | +formats= ["%Y-%m-%d %H:%M:%S.%f%z","%Y-%m-%d %H:%M:%S.%f"] |
| 124 | +forfmtinformats: |
| 125 | +try: |
| 126 | +returndatetime.strptime(str_time,fmt).isoformat()+'Z' |
| 127 | +exceptValueError: |
| 128 | +pass |
| 129 | +logging.error("Failed to parse time string: {}".format(str_time)) |