Your advanced code editor is loading.

Please wait a moment.

#editor-loading { display: none; }

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.

import sys import logging logging.basicConfig(level=logging.INFO)

class Config: # Validate config, exit if an error is detected def init(self, lock, lease_duration, renew_deadline, retry_period, onstarted_leading, onstopped_leading): self.jitter_factor = 1.2

    if lock is None:
          sys.exit("lock cannot be None")
          self.lock = lock
          
          if lease_duration <= renew_deadline:
          sys.exit("lease_duration must be greater than renew_deadline")
          if renew_deadline <= self.jitter_factor * retry_period:
          sys.exit("renewDeadline must be greater than retry_period*jitter_factor")
          if lease_duration < 1:
          sys.exit("lease_duration must be greater than one")
          if renew_deadline < 1:
          sys.exit("renew_deadline must be greater than one")
          if retry_period < 1:
          sys.exit("retry_period must be greater than one")
          self.lease_duration = lease_duration
          self.renew_deadline = renew_deadline
          self.retry_period = retry_period
          if onstarted_leading is None:
          sys.exit("callback onstarted_leading cannot be None")
          self.onstarted_leading = onstarted_leading
          if onstopped_leading is None:
          self.onstopped_leading = self.on_stoppedleading_callback
          else:
          self.onstopped_leading = onstopped_leading
          Default callback for when the current candidate if a leader, stops leading
          def on_stoppedleading_callback(self):
          logging.info("stopped leading".format(self.lock.identity))

Explanation

The code defines a Config class used for configuring leader election in Kubernetes. The class encapsulates parameters and callbacks for managing the leadership status of a pod.

__init__:
Takes parameters related to lease duration, renewal deadlines, retry periods, and callbacks for leader election.
Performs validation on these parameters to ensure they adhere to the defined constraints:
lease_duration must be greater than renew_deadline.
renew_deadline must be greater than retry_period multiplied by jitter_factor (1.2).
All three durations (lease_duration, renew_deadline, retry_period) must be greater than 1.
Stores the validated parameters as attributes of the Config object.
Sets the onstopped_leading callback to a default function (on_stoppedleading_callback) if no specific callback is provided.
on_stoppedleading_callback:
A default callback function that logs a message when the current candidate stops leading.

Key Concepts:

Leader Election: A mechanism in Kubernetes to select a single pod in a deployment or replication controller as the leader. The leader is responsible for handling specific tasks or coordinating actions among the pods.
Lease Duration: The maximum time a leader can hold its position before needing to renew its leadership.
Renew Deadline: The deadline within which a leader must renew its lease to avoid losing leadership.
Retry Period: The interval between retries to acquire leadership after a failure.
Jitter Factor: A factor used to introduce random delays in the retry period to avoid synchronized retries by multiple candidates.
Callback Functions: Functions passed to the Config object to handle events related to leadership changes (e.g., onstarted_leading, onstopped_leading).

Usage:

The Config class is used to create an instance that holds the configuration for leader election. This instance is then passed to the leader election library (likely within the kubernetes module) to initiate the election process.

Note:

The code snippet lacks information about the lock parameter, which is likely an object representing the shared lock used for leadership coordination. The specific implementation of this lock is likely dependent on the Kubernetes API and the chosen leader election method.

Your advanced code editor is loading.

Please wait a moment.

Explanation

Graph

Symbols

We couldn't identify any entrypoints. If you believe this to be incorrect then please contact support.