The leader uses a Kubernetes Lease to make sure the operator only runs on one single replica (the leader) at the same time.

Enabling the Leader Election

Functionality still in Beta

The leader election is still being tested. Enable it for testing purposes only and please report any issues on Github.

To enable leader election you have to pass the enable_leader_election: true option when adding the operator to your Supervisor:

defmodule MyOperator.Application do
  use Application

  def start(_type, env: env) do
    children = [
      {MyOperator.Operator,
      conn: MyOperator.K8sConn.get!(env),
      watch_namespace: :all,
      enable_leader_election: true} # <-- starts the leader elector
    ]

    opts = [strategy: :one_for_one, name: MyOperator.Supervisor]
    Supervisor.start_link(children, opts)
  end
end