ubicloud/prog/postgres/postgres_resource_nexus.rb

# frozen_string_literal: true

require "forwardable"

require_relative "../../lib/util"

class Prog::Postgres::PostgresResourceNexus < Prog::Base
  subject_is :postgres_resource

  extend Forwardable
  def_delegators :postgres_resource, :servers, :representative_server

  def self.assemble(project_id:, location_id:, name:, target_vm_size:, target_storage_size_gib:,
    version: PostgresResource::DEFAULT_VERSION, flavor: PostgresResource::Flavor::STANDARD,
    ha_type: PostgresResource::HaType::NONE, parent_id: nil, restore_target: nil)

    unless Project[project_id]
      fail "No existing project"
    end

    unless (location = Location[location_id])
      fail "No existing location"
    end

    DB.transaction do
      superuser_password, timeline_id, timeline_access, version = if parent_id.nil?
        [SecureRandom.urlsafe_base64(15), Prog::Postgres::PostgresTimelineNexus.assemble(location_id: location.id).id, "push", version]
      else
        unless (parent = PostgresResource[parent_id])
          fail "No existing parent"
        end

        if version && version != parent.version
          fail Validation::ValidationFailed.new({version: "Version must be the same as the parent"})
        end

        if restore_target
          restore_target = Validation.validate_date(restore_target, "restore_target")
          earliest_restore_time = parent.timeline.earliest_restore_time
          latest_restore_time = parent.timeline.latest_restore_time

          unless earliest_restore_time && earliest_restore_time <= restore_target &&
              latest_restore_time && restore_target <= latest_restore_time
            fail Validation::ValidationFailed.new({restore_target: "Restore target must be between #{earliest_restore_time} and #{latest_restore_time}"})
          end
        end
        [parent.superuser_password, parent.timeline.id, "fetch", parent.version]
      end

      postgres_resource = PostgresResource.create(
        project_id: project_id, location_id: location.id, name: name,
        target_vm_size: target_vm_size, target_storage_size_gib: target_storage_size_gib,
        superuser_password: superuser_password, ha_type: ha_type, version: version, flavor: flavor,
        parent_id: parent_id, restore_target: restore_target, hostname_version: "v2"
      )

      firewall = Firewall.create(name: "#{postgres_resource.ubid}-firewall", location_id: location.id, description: "Postgres default firewall", project_id: Config.postgres_service_project_id)

      private_subnet_id = Prog::Vnet::SubnetNexus.assemble(Config.postgres_service_project_id, name: "#{postgres_resource.ubid}-subnet", location_id: location.id, firewall_id: firewall.id).id
      postgres_resource.update(private_subnet_id: private_subnet_id)

      PostgresFirewallRule.create(postgres_resource_id: postgres_resource.id, cidr: "0.0.0.0/0")
      postgres_resource.set_firewall_rules

      Prog::Postgres::PostgresServerNexus.assemble(resource_id: postgres_resource.id, timeline_id: timeline_id, timeline_access: timeline_access, representative_at: Time.now)

      Strand.create_with_id(postgres_resource.id, prog: "Postgres::PostgresResourceNexus", label: "start")
    end
  end

  def before_run
    when_destroy_set? do
      if strand.label != "destroy"
        postgres_resource.active_billing_records.each(&:finalize)
        hop_destroy
      end
    end
  end

  label def start
    nap 5 unless representative_server.vm.strand.label == "wait"

    postgres_resource.incr_initial_provisioning
    if postgres_resource.parent
      bud self.class, frame, :trigger_pg_current_xact_id_on_parent
      register_deadline("wait", 120 * 60)
    else
      register_deadline("wait", 10 * 60)
    end
    hop_refresh_dns_record
  end

  label def trigger_pg_current_xact_id_on_parent
    postgres_resource.parent.representative_server.run_query("SELECT pg_current_xact_id()")
    pop "triggered pg_current_xact_id"
  end

  label def refresh_dns_record
    decr_refresh_dns_record

    type, data = postgres_resource.location.aws? ? ["CNAME", representative_server.vm.aws_instance.ipv4_dns_name + "."] : ["A", representative_server.vm.ephemeral_net4.to_s]

    Prog::Postgres::PostgresResourceNexus.dns_zone&.delete_record(record_name: postgres_resource.hostname)
    Prog::Postgres::PostgresResourceNexus.dns_zone&.insert_record(record_name: postgres_resource.hostname, type:, ttl: 10, data:)

    when_initial_provisioning_set? do
      hop_initialize_certificates
    end
    hop_wait
  end

  label def initialize_certificates
    # Each root will be valid for 10 years and will be used to generate server
    # certificates between its 4th and 9th years. To simulate this behaviour
    # without excessive branching, we create the very first root certificate
    # with only 5 year validity. So it would look like it is created 5 years
    # ago.
    postgres_resource.root_cert_1, postgres_resource.root_cert_key_1 = Util.create_root_certificate(common_name: "#{postgres_resource.ubid} Root Certificate Authority", duration: 60 * 60 * 24 * 365 * 5)
    postgres_resource.root_cert_2, postgres_resource.root_cert_key_2 = Util.create_root_certificate(common_name: "#{postgres_resource.ubid} Root Certificate Authority", duration: 60 * 60 * 24 * 365 * 10)
    postgres_resource.server_cert, postgres_resource.server_cert_key = create_certificate
    postgres_resource.save_changes

    reap(:wait_servers, nap: 5)
  end

  label def refresh_certificates
    # We stop using root_cert_1 to sign server certificates at the beginning
    # of 9th year of its validity. However it is possible that it is used to
    # sign a server just at the beginning of the 9 year mark, thus it needs
    # to be in the list of trusted roots until that server certificate expires.
    # 10 year - (9 year + 6 months) - (1 month padding) = 5 months. So we will
    # rotate the root_cert_1 with root_cert_2 if the remaining time is less
    # than 5 months.
    if OpenSSL::X509::Certificate.new(postgres_resource.root_cert_1).not_after < Time.now + 60 * 60 * 24 * 30 * 5
      postgres_resource.root_cert_1, postgres_resource.root_cert_key_1 = postgres_resource.root_cert_2, postgres_resource.root_cert_key_2
      postgres_resource.root_cert_2, postgres_resource.root_cert_key_2 = Util.create_root_certificate(common_name: "#{postgres_resource.ubid} Root Certificate Authority", duration: 60 * 60 * 24 * 365 * 10)
      servers.each(&:incr_refresh_certificates)
    end

    if OpenSSL::X509::Certificate.new(postgres_resource.server_cert).not_after < Time.now + 60 * 60 * 24 * 30
      postgres_resource.server_cert, postgres_resource.server_cert_key = create_certificate
      servers.each(&:incr_refresh_certificates)
    end

    postgres_resource.certificate_last_checked_at = Time.now
    postgres_resource.save_changes

    hop_wait
  end

  label def wait_servers
    nap 5 if servers.any? { it.strand.label != "wait" }
    hop_update_billing_records
  end

  label def update_billing_records
    decr_update_billing_records

    postgres_resource.active_billing_records.each(&:finalize)

    flavor = postgres_resource.flavor
    vm_family = representative_server.vm.family
    vcpu_count = representative_server.vm.vcpus
    storage_size_gib = representative_server.storage_size_gib

    billing_record_parts = []
    postgres_resource.target_server_count.times do |index|
      billing_record_parts.push({resource_type: index.zero? ? "PostgresVCpu" : "PostgresStandbyVCpu", resource_family: "#{flavor}-#{vm_family}", amount: vcpu_count})
      billing_record_parts.push({resource_type: index.zero? ? "PostgresStorage" : "PostgresStandbyStorage", resource_family: flavor, amount: storage_size_gib})
    end

    billing_record_parts.each do |brp|
      BillingRecord.create(
        project_id: postgres_resource.project_id,
        resource_id: postgres_resource.id,
        resource_name: postgres_resource.name,
        billing_rate_id: BillingRate.from_resource_properties(brp[:resource_type], brp[:resource_family], Location[postgres_resource.location_id].name)["id"],
        amount: brp[:amount]
      )
    end

    decr_initial_provisioning
    hop_wait
  end

  label def wait
    reap(fallthrough: true)

    if postgres_resource.needs_convergence? && strand.children_dataset.where(prog: "Postgres::ConvergePostgresResource").empty?
      bud Prog::Postgres::ConvergePostgresResource, frame, :start
    end

    when_update_billing_records_set? do
      hop_update_billing_records
    end

    when_refresh_dns_record_set? do
      hop_refresh_dns_record
    end

    if postgres_resource.certificate_last_checked_at < Time.now - 60 * 60 * 24 * 30 # ~1 month
      hop_refresh_certificates
    end

    when_update_firewall_rules_set? do
      decr_update_firewall_rules
      postgres_resource.set_firewall_rules
    end

    when_promote_set? do
      if postgres_resource.read_replica?
        postgres_resource.servers.each(&:incr_promote)
        postgres_resource.update(parent_id: nil)
      end
      decr_promote
    end

    nap 30
  end

  label def destroy
    register_deadline(nil, 5 * 60)

    decr_destroy

    strand.children.each { it.destroy }
    postgres_resource.private_subnet.firewalls.each(&:destroy)
    postgres_resource.private_subnet.incr_destroy
    servers.each(&:incr_destroy)

    Prog::Postgres::PostgresResourceNexus.dns_zone&.delete_record(record_name: postgres_resource.hostname)
    postgres_resource.destroy

    pop "postgres resource is deleted"
  end

  def create_certificate
    root_cert = OpenSSL::X509::Certificate.new(postgres_resource.root_cert_1)
    root_cert_key = OpenSSL::PKey::EC.new(postgres_resource.root_cert_key_1)
    if root_cert.not_after < Time.now + 60 * 60 * 24 * 365 * 1
      root_cert = OpenSSL::X509::Certificate.new(postgres_resource.root_cert_2)
      root_cert_key = OpenSSL::PKey::EC.new(postgres_resource.root_cert_key_2)
    end

    Util.create_certificate(
      subject: "/C=US/O=Ubicloud/CN=#{postgres_resource.identity}",
      extensions: ["subjectAltName=DNS:#{postgres_resource.identity},DNS:#{postgres_resource.hostname}", "keyUsage=digitalSignature,keyEncipherment", "subjectKeyIdentifier=hash", "extendedKeyUsage=serverAuth,clientAuth"],
      duration: 60 * 60 * 24 * 30 * 6, # ~6 months
      issuer_cert: root_cert,
      issuer_key: root_cert_key
    ).map(&:to_pem)
  end

  # :nocov:
  def self.freeze
    dns_zone
    super
  end
  # :nocov:

  def self.dns_zone
    return @dns_zone if defined?(@dns_zone)
    @dns_zone = DnsZone[project_id: Config.postgres_service_project_id, name: Config.postgres_service_hostname]
  end
end