Method: Puppet::Transaction#evaluate

Defined in:

lib/puppet/transaction.rb

#evaluate(&block) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

This method does all the actual work of running a transaction. It collects all of the changes, executes them, and responds to any necessary events.

# File 'lib/puppet/transaction.rb', line 97

def evaluate(&block)
  block ||= method(:eval_resource)
  generator = AdditionalResourceGenerator.new(@catalog, nil, @prioritizer)
  @catalog.vertices.each { |resource| generator.generate_additional_resources(resource) }

  perform_pre_run_checks

  persistence.load if persistence.enabled?(catalog)

  Puppet.info _("Applying configuration version '%{version}'") % { version: catalog.version } if catalog.version

  continue_while = -> { !stop_processing? }

  post_evalable_providers = Set.new
  pre_process = lambda do |resource|
    prov_class = resource.provider.class
    post_evalable_providers << prov_class if prov_class.respond_to?(:post_resource_eval)

    prefetch_if_necessary(resource)

    # If we generated resources, we don't know what they are now
    # blocking, so we opt to recompute it, rather than try to track every
    # change that would affect the number.
    relationship_graph.clear_blockers if generator.eval_generate(resource)
  end

  providerless_types = []
  overly_deferred_resource_handler = lambda do |resource|
    # We don't automatically assign unsuitable providers, so if there
    # is one, it must have been selected by the user.
    return if missing_tags?(resource)

    if resource.provider
      resource.err _("Provider %{name} is not functional on this host") % { name: resource.provider.class.name }
    else
      providerless_types << resource.type
    end

    resource_status(resource).failed = true
  end

  canceled_resource_handler = lambda do |resource|
    resource_status(resource).skipped = true
    resource.debug "Transaction canceled, skipping"
  end

  teardown = lambda do
    # Just once per type. No need to punish the user.
    providerless_types.uniq.each do |type|
      Puppet.err _("Could not find a suitable provider for %{type}") % { type: type }
    end

    post_evalable_providers.each do |provider|
      provider.post_resource_eval
    rescue => detail
      Puppet.log_exception(detail, _("post_resource_eval failed for provider %{provider}") % { provider: provider })
    end

    persistence.save if persistence.enabled?(catalog)
  end

  # Graph cycles are returned as an array of arrays
  # - outer array is an array of cycles
  # - each inner array is an array of resources involved in a cycle
  # Short circuit resource evaluation if we detect cycle(s) in the graph. Mark
  # each corresponding resource as failed in the report before we fail to
  # ensure accurate reporting.
  graph_cycle_handler = lambda do |cycles|
    cycles.flatten.uniq.each do |resource|
      # We add a failed resource event to the status to ensure accurate
      # reporting through the event manager.
      resource_status(resource).fail_with_event(_('resource is part of a dependency cycle'))
    end
    raise Puppet::Error, _('One or more resource dependency cycles detected in graph')
  end

  # Generate the relationship graph, set up our generator to use it
  # for eval_generate, then kick off our traversal.
  generator.relationship_graph = relationship_graph
  progress = 0
  relationship_graph.traverse(:while => continue_while,
                              :pre_process => pre_process,
                              :overly_deferred_resource_handler => overly_deferred_resource_handler,
                              :canceled_resource_handler => canceled_resource_handler,
                              :graph_cycle_handler => graph_cycle_handler,
                              :teardown => teardown) do |resource|
    progress += 1
    if resource.is_a?(Puppet::Type::Component)
      Puppet.warning _("Somehow left a component in the relationship graph")
    else
      if Puppet[:evaltrace] && @catalog.host_config?
        resource.info _("Starting to evaluate the resource (%{progress} of %{total})") % { progress: progress, total: relationship_graph.size }
      end
      seconds = thinmark { block.call(resource) }
      resource.info _("Evaluated in %{seconds} seconds") % { seconds: "%0.2f" % seconds } if Puppet[:evaltrace] && @catalog.host_config?
    end
  end

  # if one or more resources has attempted and failed to generate resources,
  # report it
  if generator.resources_failed_to_generate
    report.resources_failed_to_generate = true
  end

  # mark the end of transaction evaluate.
  report.transaction_completed = true

  Puppet.debug { "Finishing transaction #{object_id}" }
end