Fixing #2694 - resource guards are executed in why_run modetball/guard_interpreter

5 files changed, 39 insertions, 1 deletions

diff --git a/lib/chef/guard_interpreter/resource_guard_interpreter.rb b/lib/chef/guard_interpreter/resource_guard_interpreter.rb
index 346b585d8c..7d9bccb6ca 100644
--- a/lib/chef/guard_interpreter/resource_guard_interpreter.rb
+++ b/lib/chef/guard_interpreter/resource_guard_interpreter.rb
@@ -95,6 +95,7 @@ class Chef
         empty_events = Chef::EventDispatch::Dispatcher.new
         anonymous_run_context = Chef::RunContext.new(parent_resource.node, {}, empty_events)
         interpreter_resource = resource_class.new('Guard resource', anonymous_run_context)
+        interpreter_resource.is_guard_interpreter = true
 
         interpreter_resource
       end
diff --git a/lib/chef/mixin/why_run.rb b/lib/chef/mixin/why_run.rb
index d650e3332f..d3acea5490 100644
--- a/lib/chef/mixin/why_run.rb
+++ b/lib/chef/mixin/why_run.rb
@@ -48,7 +48,7 @@ class Chef
         # block/proc that implements the action.
         def add_action(descriptions, &block)
           @actions << [descriptions, block]
-          if !Chef::Config[:why_run]
+          if (@resource.respond_to?(:is_guard_interpreter) && @resource.is_guard_interpreter) || !Chef::Config[:why_run]
             block.call
           end
           events.resource_update_applied(@resource, @action, descriptions)
diff --git a/lib/chef/resource/execute.rb b/lib/chef/resource/execute.rb
index 6853b62887..9f8b629fb8 100644
--- a/lib/chef/resource/execute.rb
+++ b/lib/chef/resource/execute.rb
@@ -26,6 +26,12 @@ class Chef
 
       identity_attr :command
 
+      # The ResourceGuardInterpreter wraps a resource's guards in another resource.  That inner resource
+      # needs to behave differently during (for example) why_run mode, so we flag it here. For why_run mode
+      # we still want to execute the guard resource even if we are not executing the wrapping resource.
+      # Only execute resources (and subclasses) can be guard interpreters.
+      attr_accessor :is_guard_interpreter
+
       def initialize(name, run_context=nil)
         super
         @resource_name = :execute
@@ -43,6 +49,7 @@ class Chef
         @allowed_actions.push(:run)
         @umask = nil
         @default_guard_interpreter = :execute
+        @is_guard_interpreter = false
       end
 
       def umask(arg=nil)
diff --git a/spec/functional/resource/execute_spec.rb b/spec/functional/resource/execute_spec.rb
index cebcc52fcf..2483472374 100644
--- a/spec/functional/resource/execute_spec.rb
+++ b/spec/functional/resource/execute_spec.rb
@@ -34,6 +34,32 @@ describe Chef::Resource::Execute do
     end
   end
 
+  describe "when why_run is enabled" do
+    before do
+      Chef::Config[:why_run] = true
+    end
+
+    let(:guard) { "ruby -e 'exit 0'" }
+    let!(:guard_resource) {
+      interpreter = Chef::GuardInterpreter::ResourceGuardInterpreter.new(resource, guard, nil)
+      interpreter.send(:get_interpreter_resource, resource)
+    }
+
+    it "executes the guard and not the regular resource" do
+      expect_any_instance_of(Chef::GuardInterpreter::ResourceGuardInterpreter).to receive(:get_interpreter_resource).and_return(guard_resource)
+
+      # why_run mode doesn't disable the updated_by_last_action logic, so we really have to look at the provider action
+      # to see if why_run correctly disabled the resource.  It should shell_out! for the guard but not the resource.
+      expect_any_instance_of(Chef::Provider::Execute).to receive(:shell_out!).once
+
+      resource.only_if guard
+      resource.run_action(:run)
+
+      expect(resource).to be_updated_by_last_action
+      expect(guard_resource).to be_updated_by_last_action
+    end
+  end
+
   describe "when parent resource sets :cwd" do
     let(:guard) { %{ruby -e 'exit 1 unless File.exists?("./big_json_plus_one.json")'} }
 
diff --git a/spec/unit/resource/execute_spec.rb b/spec/unit/resource/execute_spec.rb
index 70b9d87d4c..09160ddbd0 100644
--- a/spec/unit/resource/execute_spec.rb
+++ b/spec/unit/resource/execute_spec.rb
@@ -28,4 +28,8 @@ describe Chef::Resource::Execute do
     expect(execute_resource.guard_interpreter).to be(:execute)
   end
 
+  it "defaults to not being a guard interpreter" do
+    expect(execute_resource.is_guard_interpreter).to eq(false)
+  end
+
 end