You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: minio_server.rb
    path of file: ./repos/ubicloud/model/minio
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

require "net/ssh"
require_relative "../../model"

class MinioServer < Sequel::Model
  one_to_one :strand, key: :id
  many_to_one :project
  many_to_one :vm, key: :vm_id, class: :Vm
  one_to_many :active_billing_records, class: :BillingRecord, key: :resource_id, conditions: {Sequel.function(:upper, :span) => nil}
  many_to_one :pool, key: :minio_pool_id, class: :MinioPool
  one_through_many :cluster, [[:minio_server, :id, :minio_pool_id], [:minio_pool, :id, :cluster_id]], class: :MinioCluster

  dataset_module Authorization::Dataset

  include ResourceMethods
  include SemaphoreMethods
  include HealthMonitorMethods

  semaphore :checkup, :destroy, :restart, :reconfigure, :refresh_certificates

  plugin :column_encryption do |enc|
    enc.column :cert_key
  end

  def hostname
    "#{cluster.name}#{index}.#{Config.minio_host_name}"
  end

  def private_ipv4_address
    vm.nics.first.private_ipv4.network.to_s
  end

  de
    
  def minio_volumes
    cluster.pools.map do |pool|
      pool.volumes_url
    end.join(" ")
  end

  def ip4_url
    "https://#{vm.ephemeral_net4}:9000"
  end

  def endpoint
    cluster.dns_zone ? "#{hostname}:9000" : "#{vm.ephemeral_net4}:9000"
  end

  def init_health_monitor_session
    socket_path = File.join(Dir.pwd, "var", "health_monitor_sockets", "ms_#{vm.ephemeral_net6.nth(2)}")
    FileUtils.rm_rf(socket_path)
    FileUtils.mkdir_p(socket_path)

    ssh_session = vm.sshable.start_fresh_session
    ssh_session.forward.local(UNIXServer.new(File.join(socket_path, "health_monitor_socket")), private_ipv4_address, 9000)
    {
      ssh_session: ssh_session,
      minio_client: client(socket: File.join("unix://", socket_path, "health_monitor_socket"))
    }
  end

  def check_pulse(session:, previous_pulse:)
    reading = begin
      server_data = JSON.parse(session[:minio_client].admin_info.body)["servers"].find { _1["endpoint"] == endpoint }
      (server_data["state"] == "online" && server_data["drives"].all? { _1["state"] == "ok" }) ? "up" : "down"
    rescue
      "down"
    end
    pulse = aggregate_readings(previous_pulse: previous_pulse, reading: reading)

    if pulse[:reading] == "down" && pulse[:reading_rpt] > 5 && Time.now - pulse[:reading_chg] > 30
      incr_checkup
    end