Add unified_mode switch for resources

This is inspired by "use_inline_resources".

Setting `unified_mode false` in a resource would be the existing
behavior with separate compile/converge phases.

Setting `unified_mode true` in a resource will eliminate the converge
phase.  Reverse notifications and delayed notifications will still
fire.  The resource action will behave like all resources are executing
at compile time.

As a aside, notifications have never worked for resources firing at
compile time.  This implementation gets that behavior correct so
that notifications will work.

Of course forward immediate notifications to resources not yet declared will not
be possible.

Setting `resource_unified_mode_default true` in `Chef::Config` would
turn off the split compile/converge mode for every custom resource.

NOTE: This does not affect recipe mode at all.

Signed-off-by: Lamont Granquist <lamont@scriptkiddie.org>

1 files changed, 54 insertions, 24 deletions

diff --git a/lib/chef/run_context.rb b/lib/chef/run_context.rb
index eb211dc5a5..7a5924a3c7 100644
--- a/lib/chef/run_context.rb
+++ b/lib/chef/run_context.rb
@@ -26,12 +26,16 @@ require_relative "recipe"
 require_relative "run_context/cookbook_compiler"
 require_relative "event_dispatch/events_output_stream"
 require_relative "train_transport"
+require_relative "exceptions"
 require "forwardable" unless defined?(Forwardable)
+require "set" unless defined?(Set)
 
 class Chef
 
   # Value object that loads and tracks the context of a Chef run
   class RunContext
+    extend Forwardable
+
     #
     # Global state
     #
@@ -72,14 +76,12 @@ class Chef
     #
     attr_reader :definitions
 
-    #
     # Event dispatcher for this run.
     #
     # @return [Chef::EventDispatch::Dispatcher]
     #
     attr_accessor :events
 
-    #
     # Hash of factoids for a reboot request.
     #
     # @return [Hash]
@@ -90,7 +92,6 @@ class Chef
     # Scoped state
     #
 
-    #
     # The parent run context.
     #
     # @return [Chef::RunContext] The parent run context, or `nil` if this is the
@@ -98,7 +99,6 @@ class Chef
     #
     attr_reader :parent_run_context
 
-    #
     # The root run context.
     #
     # @return [Chef::RunContext] The root run context.
@@ -109,7 +109,6 @@ class Chef
       rc
     end
 
-    #
     # The collection of resources intended to be converged (and able to be
     # notified).
     #
@@ -119,8 +118,12 @@ class Chef
     #
     attr_reader :resource_collection
 
-    attr_accessor :action_collection
+    # Handle to the global action_collection of executed actions for reporting / data_collector /etc
+    #
+    # @return [Chef::ActionCollection
     #
+    attr_accessor :action_collection
+
     # Pointer back to the Chef::Runner that created this
     #
     attr_accessor :runner
@@ -129,7 +132,6 @@ class Chef
     # Notification handling
     #
 
-    #
     # A Hash containing the before notifications triggered by resources
     # during the converge phase of the chef run.
     #
@@ -138,7 +140,6 @@ class Chef
     #
     attr_reader :before_notification_collection
 
-    #
     # A Hash containing the immediate notifications triggered by resources
     # during the converge phase of the chef run.
     #
@@ -147,7 +148,6 @@ class Chef
     #
     attr_reader :immediate_notification_collection
 
-    #
     # A Hash containing the delayed (end of run) notifications triggered by
     # resources during the converge phase of the chef run.
     #
@@ -156,7 +156,6 @@ class Chef
     #
     attr_reader :delayed_notification_collection
 
-    #
     # An Array containing the delayed (end of run) notifications triggered by
     # resources during the converge phase of the chef run.
     #
@@ -164,7 +163,16 @@ class Chef
     #
     attr_reader :delayed_actions
 
+    # A Set keyed by the string name, of all the resources that are updated.  We do not
+    # track actions or individual resource objects, since this matches the behavior of
+    # the notification collections which are keyed by Strings.
+    #
+    attr_reader :updated_resources
+
+    # @return [Boolean] If the resource_collection is in unified_mode (no separate converge phase)
     #
+    def_delegator :resource_collection, :unified_mode
+
     # A child of the root Chef::Log logging object.
     #
     # @return Mixlib::Log::Child A child logger
@@ -190,7 +198,6 @@ class Chef
       @loaded_attributes_hash = {}
       @reboot_info = {}
       @cookbook_compiler = nil
-      @delayed_actions = []
 
       initialize_child_state
     end
@@ -221,6 +228,7 @@ class Chef
       @immediate_notification_collection = Hash.new { |h, k| h[k] = [] }
       @delayed_notification_collection = Hash.new { |h, k| h[k] = [] }
       @delayed_actions = []
+      @updated_resources = Set.new
     end
 
     #
@@ -232,6 +240,10 @@ class Chef
       # Note for the future, notification.notifying_resource may be an instance
       # of Chef::Resource::UnresolvedSubscribes when calling {Resource#subscribes}
       # with a string value.
+      if unified_mode && updated_resources.include?(notification.notifying_resource.declared_key)
+        raise Chef::Exceptions::UnifiedModeBeforeSubscriptionEarlierResource.new(notification)
+      end
+
       before_notification_collection[notification.notifying_resource.declared_key] << notification
     end
 
@@ -256,11 +268,13 @@ class Chef
       # Note for the future, notification.notifying_resource may be an instance
       # of Chef::Resource::UnresolvedSubscribes when calling {Resource#subscribes}
       # with a string value.
+      if unified_mode && updated_resources.include?(notification.notifying_resource.declared_key)
+        add_delayed_action(notification)
+      end
       delayed_notification_collection[notification.notifying_resource.declared_key] << notification
     end
 
-    #
-    # Adds a delayed action to the +delayed_actions+.
+    # Adds a delayed action to the delayed_actions collection
     #
     def add_delayed_action(notification)
       if delayed_actions.any? { |existing_notification| existing_notification.duplicates?(notification) }
@@ -271,32 +285,45 @@ class Chef
       end
     end
 
-    #
     # Get the list of before notifications sent by the given resource.
     #
     # @return [Array[Notification]]
     #
     def before_notifications(resource)
-      before_notification_collection[resource.declared_key]
+      key = resource.is_a?(String) ? resource : resource.declared_key
+      before_notification_collection[key]
     end
 
-    #
     # Get the list of immediate notifications sent by the given resource.
     #
     # @return [Array[Notification]]
     #
     def immediate_notifications(resource)
-      immediate_notification_collection[resource.declared_key]
+      key = resource.is_a?(String) ? resource : resource.declared_key
+      immediate_notification_collection[key]
     end
 
+    # Get the list of immeidate notifications pending to the given resource
+    #
+    # @return [Array[Notification]]
     #
+    def reverse_immediate_notifications(resource)
+      immediate_notification_collection.map do |k, v|
+        v.select do |n|
+          (n.resource.is_a?(String) && n.resource == resource.declared_key) ||
+            n.resource == resource
+        end
+      end.flatten
+    end
+
     # Get the list of delayed (end of run) notifications sent by the given
     # resource.
     #
     # @return [Array[Notification]]
     #
     def delayed_notifications(resource)
-      delayed_notification_collection[resource.declared_key]
+      key = resource.is_a?(String) ? resource : resource.declared_key
+      delayed_notification_collection[key]
     end
 
     #
@@ -666,9 +693,9 @@ class Chef
         rest=
         rest_clean
         rest_clean=
-        unreachable_cookbook?
         transport
         transport_connection
+        unreachable_cookbook?
       }
 
       def initialize(parent_run_context)
@@ -681,8 +708,10 @@ class Chef
       end
 
       CHILD_STATE = %w{
-        create_child
         add_delayed_action
+        before_notification_collection
+        before_notifications
+        create_child
         delayed_actions
         delayed_notification_collection
         delayed_notification_collection=
@@ -690,21 +719,22 @@ class Chef
         immediate_notification_collection
         immediate_notification_collection=
         immediate_notifications
-        before_notification_collection
-        before_notifications
         include_recipe
         initialize_child_state
         load_recipe
         load_recipe_file
         notifies_before
-        notifies_immediately
         notifies_delayed
+        notifies_immediately
         parent_run_context
-        root_run_context
         resource_collection
         resource_collection=
+        reverse_immediate_notifications
+        root_run_context
         runner
         runner=
+        unified_mode
+        updated_resources
       }.map(&:to_sym)
 
       # Verify that we didn't miss any methods