Merge branch 'CHEF-3681'

4 files changed, 167 insertions, 21 deletions

diff --git a/lib/chef/provider/lwrp_base.rb b/lib/chef/provider/lwrp_base.rb
index 1ae17e288c..90ce70ae61 100644
--- a/lib/chef/provider/lwrp_base.rb
+++ b/lib/chef/provider/lwrp_base.rb
@@ -27,6 +27,48 @@ class Chef
     # Base class from which LWRP providers inherit.
     class LWRPBase < Provider
 
+      # Chef::Provider::LWRPBase::InlineResources
+      # Implementation of inline resource convergence for LWRP providers. See
+      # Provider::LWRPBase.use_inline_resources for a longer explanation.
+      #
+      # This code is restricted to a module so that it can be selectively
+      # applied to providers on an opt-in basis.
+      module InlineResources
+
+        # Class methods for InlineResources. Overrides the `action` DSL method
+        # with one that enables inline resource convergence.
+        module ClassMethods
+          # Defines an action method on the provider, using
+          # recipe_eval_with_update_check to execute the given block.
+          def action(name, &block)
+            define_method("action_#{name}") do
+              recipe_eval_with_update_check(&block)
+            end
+          end
+        end
+
+        # Executes the given block in a temporary run_context with its own
+        # resource collection. After the block is executed, any resources
+        # declared inside are converged, and if any are updated, the
+        # new_resource will be marked updated.
+        def recipe_eval_with_update_check(&block)
+          saved_run_context = @run_context
+          temp_run_context = @run_context.dup
+          @run_context = temp_run_context
+          @run_context.resource_collection = Chef::ResourceCollection.new
+
+          return_value = instance_eval(&block)
+          Chef::Runner.new(@run_context).converge
+          return_value
+        ensure
+          @run_context = saved_run_context
+          if temp_run_context.resource_collection.any? {|r| r.updated? }
+            new_resource.updated_by_last_action(true)
+          end
+        end
+
+      end
+
       extend Chef::Mixin::ConvertToClassName
       extend Chef::Mixin::FromFile
 
@@ -58,6 +100,38 @@ class Chef
         provider_class
       end
 
+      # Enables inline evaluation of resources in provider actions.
+      #
+      # Without this option, any resources declared inside the LWRP are added
+      # to the resource collection after the current position at the time the
+      # action is executed. Because they are added to the primary resource
+      # collection for the chef run, they can notify other resources outside
+      # the LWRP, and potentially be notified by resources outside the LWRP
+      # (but this is complicated by the fact that they don't exist until the
+      # provider executes). In this mode, it is impossible to correctly set the
+      # updated_by_last_action flag on the parent LWRP resource, since it
+      # executes and returns before its component resources are run.
+      #
+      # With this option enabled, each action creates a temporary run_context
+      # with its own resource collection, evaluates the action's code in that
+      # context, and then converges the resources created. If any resources
+      # were updated, then this provider's new_resource will be marked updated.
+      #
+      # In this mode, resources created within the LWRP cannot interact with
+      # external resources via notifies, though notifications to other
+      # resources within the LWRP will work. Delayed notifications are executed
+      # at the conclusion of the provider's action, *not* at the end of the
+      # main chef run.
+      #
+      # This mode of evaluation is experimental, but is believed to be a better
+      # set of tradeoffs than the append-after mode, so it will likely become
+      # the default in a future major release of Chef.
+      #
+      def self.use_inline_resources
+        extend InlineResources::ClassMethods
+        include InlineResources
+      end
+
       # DSL for defining a provider's actions.
       def self.action(name, &block)
         define_method("action_#{name}") do
diff --git a/lib/chef/resource_collection.rb b/lib/chef/resource_collection.rb
index 51858c53d8..baf959c33b 100644
--- a/lib/chef/resource_collection.rb
+++ b/lib/chef/resource_collection.rb
@@ -7,9 +7,9 @@
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
-# 
+#
 #     http://www.apache.org/licenses/LICENSE-2.0
-# 
+#
 # Unless required by applicable law or agreed to in writing, software
 # distributed under the License is distributed on an "AS IS" BASIS,
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -23,7 +23,7 @@ require 'chef/resource_collection/stepable_iterator'
 class Chef
   class ResourceCollection
     include Enumerable
-    
+
     attr_reader :iterator
 
     def initialize
@@ -31,18 +31,18 @@ class Chef
       @resources_by_name = Hash.new
       @insert_after_idx = nil
     end
-    
+
     def all_resources
       @resources
     end
-    
+
     def [](index)
       @resources[index]
     end
-    
+
     def []=(index, arg)
       is_chef_resource(arg)
-      @resources[index] = arg 
+      @resources[index] = arg
       @resources_by_name[arg.to_s] = index
     end
 
@@ -50,7 +50,7 @@ class Chef
       args.flatten.each do |a|
         is_chef_resource(a)
         @resources << a
-        @resources_by_name[a.to_s] = @resources.length - 1 
+        @resources_by_name[a.to_s] = @resources.length - 1
       end
     end
 
@@ -67,12 +67,12 @@ class Chef
         end
         @resources_by_name[resource.to_s] = @insert_after_idx + 1
         @insert_after_idx += 1
-      else  
+      else
         @resources << resource
         @resources_by_name[resource.to_s] = @resources.length - 1
       end
     end
-    
+
     def push(*args)
       args.flatten.each do |arg|
         is_chef_resource(arg)
@@ -80,7 +80,7 @@ class Chef
         @resources_by_name[arg.to_s] = @resources.length - 1
       end
     end
-  
+
     def each
       @resources.each do |resource|
         yield resource
@@ -94,13 +94,17 @@ class Chef
         yield resource
       end
     end
-    
+
     def each_index
       @resources.each_index do |i|
         yield i
       end
     end
-    
+
+    def empty?
+      @resources.empty?
+    end
+
     def lookup(resource)
       lookup_by = nil
       if resource.kind_of?(Chef::Resource)
@@ -125,7 +129,7 @@ class Chef
     # find("file[foobar]", "file[baz]")
     # find("file[foobar,baz]")
     #
-    # Returns the matching resource, or an Array of matching resources. 
+    # Returns the matching resource, or an Array of matching resources.
     #
     # Raises an ArgumentError if you feed it bad lookup information
     # Raises a Runtime Error if it can't find the resources you are looking for.
@@ -145,12 +149,12 @@ class Chef
       flat_results = results.flatten
       flat_results.length == 1 ? flat_results[0] : flat_results
     end
-    
+
     # resources is a poorly named, but we have to maintain it for back
     # compat.
     alias_method :resources, :find
-    
-    # Serialize this object as a hash 
+
+    # Serialize this object as a hash
     def to_json(*a)
       instance_vars = Hash.new
       self.instance_variables.each do |iv|
@@ -162,7 +166,7 @@ class Chef
       }
       results.to_json(*a)
     end
-    
+
     def self.json_create(o)
       collection = self.new()
       o["instance_vars"].each do |k,v|
@@ -172,7 +176,7 @@ class Chef
     end
 
     private
-    
+
       def find_resource_by_hash(arg)
         results = Array.new
         arg.each do |resource_name, name_list|
@@ -193,7 +197,7 @@ class Chef
           arg =~ /^.+\[(.+)\]$/
           resource_list = $1
           resource_list.split(",").each do |name|
-            resource_name = "#{resource_type}[#{name}]" 
+            resource_name = "#{resource_type}[#{name}]"
             results << lookup(resource_name)
           end
         when /^(.+)\[(.+)\]$/
@@ -209,7 +213,7 @@ class Chef
 
       def is_chef_resource(arg)
         unless arg.kind_of?(Chef::Resource)
-          raise ArgumentError, "Members must be Chef::Resource's" 
+          raise ArgumentError, "Members must be Chef::Resource's"
         end
         true
       end
diff --git a/spec/data/lwrp/providers/inline_compiler.rb b/spec/data/lwrp/providers/inline_compiler.rb
new file mode 100644
index 0000000000..2535276b24
--- /dev/null
+++ b/spec/data/lwrp/providers/inline_compiler.rb
@@ -0,0 +1,26 @@
+
+use_inline_resources
+
+action :test do
+
+  ruby_block "interior-ruby-block-1" do
+    block do
+      # doesn't need to do anything
+    end
+    notifies :run, "ruby_block[interior-ruby-block-2]", :immediately
+  end
+
+  ruby_block "interior-ruby-block-2" do
+    block do
+      $interior_ruby_block_2 = "executed"
+    end
+    action :nothing
+  end
+end
+
+action :no_updates do
+  ruby_block "no-action" do
+    block {}
+    action :nothing
+  end
+end
diff --git a/spec/unit/lwrp_spec.rb b/spec/unit/lwrp_spec.rb
index b28fd812a2..a158bce440 100644
--- a/spec/unit/lwrp_spec.rb
+++ b/spec/unit/lwrp_spec.rb
@@ -226,6 +226,48 @@ describe "LWRP" do
       provider.enclosed_resource.monkey.should == 'bob, the monkey'
     end
 
+    describe "when using inline compilation" do
+      before do
+        # Behavior in these examples depends on implementation of fixture provider.
+        # See spec/data/lwrp/providers/inline_compiler
+
+        # Side effect of lwrp_inline_compiler provider for testing notifications.
+        $interior_ruby_block_2 = nil
+        # resource type doesn't matter, so make an existing resource type work with provider.
+        @resource = Chef::Resource::LwrpFoo.new("morpheus", @run_context)
+        @resource.allowed_actions << :test
+        @resource.action(:test)
+        @resource.provider(:lwrp_inline_compiler)
+      end
+
+      it "does not add interior resources to the exterior resource collection" do
+        @resource.run_action(:test)
+        @run_context.resource_collection.should be_empty
+      end
+
+      context "when interior resources are updated" do
+        it "processes notifications within the LWRP provider's action" do
+          @resource.run_action(:test)
+          $interior_ruby_block_2.should == "executed"
+        end
+
+        it "marks the parent resource updated" do
+          @resource.run_action(:test)
+          @resource.should be_updated
+          @resource.should be_updated_by_last_action
+        end
+      end
+
+      context "when interior resources are not updated" do
+        it "does not mark the parent resource updated" do
+          @resource.run_action(:no_updates)
+          @resource.should_not be_updated
+          @resource.should_not be_updated_by_last_action
+        end
+      end
+
+    end
+
   end
 
 end