Reset the plugin information when all_plugins is called consecutively in order to pick up any changes to the plugins that happened in the meantime.

This is needed for ohai resource of Chef which calls all_plugins during :reload action.

3 files changed, 76 insertions, 9 deletions

diff --git a/lib/ohai/system.rb b/lib/ohai/system.rb
index 8569ba2c..f5414cf8 100644
--- a/lib/ohai/system.rb
+++ b/lib/ohai/system.rb
@@ -38,16 +38,23 @@ module Ohai
     attr_reader :v6_dependency_solver
 
     def initialize
+      @plugin_path = ""
+      reset_system
+    end
+
+    def reset_system
       @data = Mash.new
       @provides_map = ProvidesMap.new
 
       @v6_dependency_solver = Hash.new
-      @plugin_path = ""
 
       @loader = Ohai::Loader.new(self)
       @runner = Ohai::Runner.new(self, true)
 
       Ohai::Hints.refresh_hints()
+
+      # Remove the previously defined plugins
+      recursive_remove_constants(Ohai::NamedPlugin)
     end
 
     def [](key)
@@ -55,6 +62,11 @@ module Ohai
     end
 
     def all_plugins(attribute_filter=nil)
+      # Reset the system when all_plugins is called since this function
+      # can be run multiple times in order to pick up any changes in the
+      # config or plugins with Chef.
+      reset_system
+
       load_plugins
       run_plugins(true, attribute_filter)
     end
@@ -138,10 +150,10 @@ module Ohai
     # of them whenever called.
     def refresh_plugins(attribute_filter=nil)
       Ohai::Hints.refresh_hints()
-      @provides_map.all_plugins(Array(attribute_filter)).each do |plugin|
+      @provides_map.all_plugins(attribute_filter).each do |plugin|
         plugin.reset!
       end
-      run_plugins(true, Array(attribute_filter))
+      run_plugins(true, attribute_filter)
     end
 
     #
@@ -178,5 +190,23 @@ module Ohai
       end
     end
 
+    private
+    def recursive_remove_constants(object)
+      if object.respond_to?(:constants)
+        object.constants.each do |const|
+          next unless strict_const_defined?(object, const)
+          recursive_remove_constants(object.const_get(const))
+          object.send(:remove_const, const)
+        end
+      end
+    end
+
+    def strict_const_defined?(object, const)
+      if object.method(:const_defined?).arity == 1
+        object.const_defined?(const)
+      else
+        object.const_defined?(const, false)
+      end
+    end
   end
 end
diff --git a/spec/unit/runner_spec.rb b/spec/unit/runner_spec.rb
index f24d6373..880f1ebb 100644
--- a/spec/unit/runner_spec.rb
+++ b/spec/unit/runner_spec.rb
@@ -284,8 +284,7 @@ describe Ohai::Runner, "run_plugin" do
   end
 
   describe "when a cycle is detected" do
-    let(:ohai) { Ohai::System.new }
-    let(:runner) { Ohai::Runner.new(ohai, true) }
+    let(:runner) { Ohai::Runner.new(@ohai, true) }
 
     context "when there are no edges in the cycle (A->A)" do
       let(:plugin_class) do
@@ -297,10 +296,10 @@ describe Ohai::Runner, "run_plugin" do
           end
         end
       end
-      let(:plugin) { plugin_class.new(ohai.data) }
+      let(:plugin) { plugin_class.new(@ohai.data) }
 
       it "ignores the cycle" do
-        ohai.provides_map.set_providers_for(plugin, ["thing"])
+        @ohai.provides_map.set_providers_for(plugin, ["thing"])
 
         expected_error_string = "Dependency cycle detected. Please refer to the following plugins: Thing, Other"
         runner.run_plugin(plugin) # should not raise
@@ -327,8 +326,9 @@ describe Ohai::Runner, "run_plugin" do
 
         @plugins = []
         [klass1, klass2].each_with_index do |klass, idx|
-          @plugins << klass.new(ohai.data)
+          @plugins << klass.new(@ohai.data)
         end
+
         @plugin1, @plugin2 = @plugins
       end
 
diff --git a/spec/unit/system_spec.rb b/spec/unit/system_spec.rb
index d40533bc..306c33b0 100644
--- a/spec/unit/system_spec.rb
+++ b/spec/unit/system_spec.rb
@@ -209,7 +209,9 @@ EOF
 
           ohai_system.v6_dependency_solver["v6_plugin"] = v6_plugin
 
-          ohai_system.all_plugins("primary")
+          # Instead of calling all plugins we call load and run directly so that the information we setup is not cleared by all_plugins
+          ohai_system.load_plugins
+          ohai_system.run_plugins(true, "primary")
         end
 
         # This behavior choice is somewhat arbitrary, based on what creates the
@@ -286,6 +288,8 @@ EOF
 
       it "should write an error to Ohai::Log" do
         Ohai::Config[:plugin_path] = [ path_to(".") ]
+        # Make sure the stubbing of runner is not overriden with reset_system during test
+        @ohai.stub(:reset_system)
         @ohai.instance_variable_get("@runner").stub(:run_plugin).and_raise(Ohai::Exceptions::AttributeNotFound)
         Ohai::Log.should_receive(:error).with(/Encountered error while running plugins/)
         expect { @ohai.all_plugins }.to raise_error(Ohai::Exceptions::AttributeNotFound)
@@ -524,6 +528,39 @@ EOF
     end
   end
 
+  describe "when Chef OHAI resource executes :reload action" do
+    when_plugins_directory "contains a random plugin" do
+      with_plugin("random.rb", <<-E)
+        Ohai.plugin(:Random) do
+          provides 'random'
+
+          collect_data do
+            random rand(100)
+          end
+        end
+      E
+
+      before do
+        @ohai = Ohai::System.new
+        @original_config = Ohai::Config[:plugin_path]
+        Ohai::Config[:plugin_path] = [ path_to(".") ]
+      end
+
+      after do
+        Ohai::Config[:plugin_path] = @original_config
+      end
+
+      it "should rerun the plugin providing the desired attributes", :focus => true do
+        @ohai.all_plugins
+        initial_value = @ohai.data["random"]
+        @ohai.all_plugins
+        updated_value = @ohai.data["random"]
+        initial_value.should_not == updated_value
+      end
+
+    end
+  end
+
   describe "when refreshing plugins" do
     when_plugins_directory "contains v7 plugins" do
       with_plugin("desired.rb", <<-E)