129 lines
No EOL
5.7 KiB
Python
129 lines
No EOL
5.7 KiB
Python
# Copyright 2021 The Kubernetes Authors.
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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from kubernetes.client.rest import ApiException
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from kubernetes import client, config
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from kubernetes.client.api_client import ApiClient
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from ..leaderelectionrecord import LeaderElectionRecord
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import json
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import logging
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logging.basicConfig(level=logging.INFO)
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class ConfigMapLock:
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def __init__(self, name, namespace, identity):
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"""
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:param name: name of the lock
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:param namespace: namespace
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:param identity: A unique identifier that the candidate is using
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"""
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self.api_instance = client.CoreV1Api()
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self.leader_electionrecord_annotationkey = 'control-plane.alpha.kubernetes.io/leader'
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self.name = name
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self.namespace = namespace
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self.identity = str(identity)
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self.configmap_reference = None
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self.lock_record = {
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'holderIdentity': None,
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'leaseDurationSeconds': None,
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'acquireTime': None,
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'renewTime': None
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}
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# get returns the election record from a ConfigMap Annotation
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def get(self, name, namespace):
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"""
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:param name: Name of the configmap object information to get
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:param namespace: Namespace in which the configmap object is to be searched
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:return: 'True, election record' if object found else 'False, exception response'
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"""
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try:
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api_response = self.api_instance.read_namespaced_config_map(name, namespace)
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# If an annotation does not exist - add the leader_electionrecord_annotationkey
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annotations = api_response.metadata.annotations
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if annotations is None or annotations == '':
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api_response.metadata.annotations = {self.leader_electionrecord_annotationkey: ''}
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self.configmap_reference = api_response
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return True, None
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# If an annotation exists but, the leader_electionrecord_annotationkey does not then add it as a key
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if not annotations.get(self.leader_electionrecord_annotationkey):
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api_response.metadata.annotations = {self.leader_electionrecord_annotationkey: ''}
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self.configmap_reference = api_response
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return True, None
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lock_record = self.get_lock_object(json.loads(annotations[self.leader_electionrecord_annotationkey]))
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self.configmap_reference = api_response
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return True, lock_record
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except ApiException as e:
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return False, e
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def create(self, name, namespace, election_record):
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"""
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:param electionRecord: Annotation string
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:param name: Name of the configmap object to be created
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:param namespace: Namespace in which the configmap object is to be created
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:return: 'True' if object is created else 'False' if failed
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"""
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body = client.V1ConfigMap(
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metadata={"name": name,
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"annotations": {self.leader_electionrecord_annotationkey: json.dumps(self.get_lock_dict(election_record))}})
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try:
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api_response = self.api_instance.create_namespaced_config_map(namespace, body, pretty=True)
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return True
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except ApiException as e:
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logging.info("Failed to create lock as {}".format(e))
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return False
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def update(self, name, namespace, updated_record):
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"""
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:param name: name of the lock to be updated
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:param namespace: namespace the lock is in
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:param updated_record: the updated election record
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:return: True if update is successful False if it fails
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"""
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try:
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# Set the updated record
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self.configmap_reference.metadata.annotations[self.leader_electionrecord_annotationkey] = json.dumps(self.get_lock_dict(updated_record))
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api_response = self.api_instance.replace_namespaced_config_map(name=name, namespace=namespace,
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body=self.configmap_reference)
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return True
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except ApiException as e:
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logging.info("Failed to update lock as {}".format(e))
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return False
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def get_lock_object(self, lock_record):
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leader_election_record = LeaderElectionRecord(None, None, None, None)
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if lock_record.get('holderIdentity'):
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leader_election_record.holder_identity = lock_record['holderIdentity']
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if lock_record.get('leaseDurationSeconds'):
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leader_election_record.lease_duration = lock_record['leaseDurationSeconds']
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if lock_record.get('acquireTime'):
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leader_election_record.acquire_time = lock_record['acquireTime']
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if lock_record.get('renewTime'):
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leader_election_record.renew_time = lock_record['renewTime']
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return leader_election_record
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def get_lock_dict(self, leader_election_record):
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self.lock_record['holderIdentity'] = leader_election_record.holder_identity
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self.lock_record['leaseDurationSeconds'] = leader_election_record.lease_duration
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self.lock_record['acquireTime'] = leader_election_record.acquire_time
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self.lock_record['renewTime'] = leader_election_record.renew_time
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return self.lock_record |