ubicloud/prog/vnet/load_balancer_nexus.rb

# frozen_string_literal: true

require "acme-client"
require "openssl"

class Prog::Vnet::LoadBalancerNexus < Prog::Base
  subject_is :load_balancer
  semaphore :destroy, :update_load_balancer, :rewrite_dns_records, :refresh_cert

  def self.assemble(private_subnet_id, name: nil, algorithm: "round_robin", src_port: nil, dst_port: nil,
    health_check_endpoint: "/up", health_check_interval: 30, health_check_timeout: 15,
    health_check_up_threshold: 3, health_check_down_threshold: 2, health_check_protocol: "http", custom_hostname_prefix: nil, custom_hostname_dns_zone_id: nil)

    unless (ps = PrivateSubnet[private_subnet_id])
      fail "Given subnet doesn't exist with the id #{private_subnet_id}"
    end

    Validation.validate_name(name)
    custom_hostname = if custom_hostname_prefix
      Validation.validate_name(custom_hostname_prefix)
      "#{custom_hostname_prefix}.#{DnsZone[custom_hostname_dns_zone_id].name}"
    end

    DB.transaction do
      lb = LoadBalancer.create_with_id(
        private_subnet_id: private_subnet_id, name: name, algorithm: algorithm, src_port: src_port, dst_port: dst_port,
        health_check_endpoint: health_check_endpoint, health_check_interval: health_check_interval,
        health_check_timeout: health_check_timeout, health_check_up_threshold: health_check_up_threshold,
        health_check_down_threshold: health_check_down_threshold, health_check_protocol: health_check_protocol,
        custom_hostname: custom_hostname, custom_hostname_dns_zone_id: custom_hostname_dns_zone_id
      )
      lb.associate_with_project(ps.projects.first)

      Strand.create(prog: "Vnet::LoadBalancerNexus", label: "wait") { _1.id = lb.id }
    end
  end

  def before_run
    when_destroy_set? do
      hop_destroy unless %w[destroy wait_destroy].include?(strand.label)
    end
  end

  label def wait
    when_update_load_balancer_set? do
      hop_update_vm_load_balancers
    end

    when_rewrite_dns_records_set? do
      rewrite_dns_records
      decr_rewrite_dns_records
    end

    if load_balancer.need_certificates?
      load_balancer.incr_refresh_cert
      hop_create_new_cert
    end

    nap 5
  end

  label def create_new_cert
    cert = Prog::Vnet::CertNexus.assemble(load_balancer.hostname, load_balancer.dns_zone&.id).subject
    load_balancer.add_cert(cert)
    hop_wait_cert_provisioning
  end

  label def wait_cert_provisioning
    if load_balancer.need_certificates?
      nap 60
    elsif load_balancer.refresh_cert_set?
      load_balancer.vms.each do |vm|
        bud Prog::Vnet::CertServer, {"subject_id" => load_balancer.id, "vm_id" => vm.id}, :reshare_certificate
      end

      hop_wait_cert_broadcast
    end

    hop_wait
  end

  label def wait_cert_broadcast
    reap
    if strand.children.select { _1.prog == "Vnet::CertServer" }.all? { _1.exitval == "certificate is reshared" } || strand.children.empty?
      decr_refresh_cert
      hop_wait
    end

    nap 1
  end

  label def update_vm_load_balancers
    load_balancer.vms.each do |vm|
      bud Prog::Vnet::UpdateLoadBalancerNode, {"subject_id" => vm.id, "load_balancer_id" => load_balancer.id}, :update_load_balancer
    end

    hop_wait_update_vm_load_balancers
  end

  label def wait_update_vm_load_balancers
    reap
    if strand.children_dataset.where(prog: "Vnet::UpdateLoadBalancerNode").all? { _1.exitval == "load balancer is updated" } || strand.children.empty?
      decr_update_load_balancer
      hop_wait
    end

    nap 1
  end

  label def destroy
    decr_destroy
    strand.children.map { _1.destroy }
    # The following if statement makes sure that it's OK to not have dns_zone
    # only if it's not in production.
    if (dns_zone = load_balancer.dns_zone) && (Config.production? || dns_zone)
      dns_zone.delete_record(record_name: load_balancer.hostname)
    end

    load_balancer.vms.each do |vm|
      bud Prog::Vnet::UpdateLoadBalancerNode, {"subject_id" => vm.id, "load_balancer_id" => load_balancer.id}, :update_load_balancer
      bud Prog::Vnet::CertServer, {"subject_id" => load_balancer.id, "vm_id" => vm.id}, :remove_cert_server
    end

    hop_wait_destroy
  end

  label def wait_destroy
    reap
    if leaf?
      load_balancer.projects.each { |prj| load_balancer.dissociate_with_project(prj) }
      load_balancer.destroy

      pop "load balancer deleted"
    end

    nap 5
  end

  def rewrite_dns_records
    load_balancer.dns_zone&.delete_record(record_name: load_balancer.hostname)

    load_balancer.vms_to_dns.map do |vm|
      load_balancer.dns_zone&.insert_record(record_name: load_balancer.hostname, type: "A", ttl: 10, data: vm.ephemeral_net4.to_s) if vm.ephemeral_net4
      load_balancer.dns_zone&.insert_record(record_name: load_balancer.hostname, type: "AAAA", ttl: 10, data: vm.ephemeral_net6.nth(2).to_s)
    end
  end
end