Extra debug logging and error handling in plugin loading

lib/ohai/application.rb

@@ -33,7 +33,7 @@ class Ohai::Application
   option :directory,
     :short       => "-d DIRECTORY",
     :long        => "--directory DIRECTORY",
-    :description => "A directory to add to the Ohai search path",
+    :description => "A directory to add to the Ohai plugin search path",
     :proc        => lambda { |path| Ohai::Config.platform_specific_path(path) }
 
   option :log_level,

lib/ohai/loader.rb

@@ -39,6 +39,13 @@ class PluginFile < Struct.new(:path, :plugin_root)
 
       # Finds all the *.rb files under the configured paths in :plugin_path
       def self.find_all_in(plugin_dir)
+        unless Dir.exist?(plugin_dir)
+          Ohai::Log.warn("The plugin path #{plugin_dir} does not exist. Skipping...")
+          return []
+        end
+
+        Ohai::Log.debug("Searching for Ohai plugins in #{plugin_dir}")
+
         # escape_glob_dir does not exist in 12.7 or below
         if ChefConfig::PathHelper.respond_to?(:escape_glob_dir)
           escaped = ChefConfig::PathHelper.escape_glob_dir(plugin_dir)
@@ -105,6 +112,7 @@ def load_plugin_class(plugin_path, plugin_dir_path = nil)
       # Read the contents of the plugin to understand if it's a V6 or V7 plugin.
       contents = ""
       begin
+        Ohai::Log.debug("Loading plugin at #{plugin_path}")
         contents << IO.read(plugin_path)
       rescue IOError, Errno::ENOENT
         Ohai::Log.warn("Unable to open or read plugin at #{plugin_path}")

lib/ohai/system.rb

@@ -215,6 +215,8 @@ def configure_ohai
           !Ohai.config[:plugin_path].include?(Ohai.config[:directory])
         Ohai.config[:plugin_path] << Ohai.config[:directory]
       end
+
+      Ohai::Log.debug("Running Ohai with the following configuration: #{Ohai.config.configuration}")
     end
 
     def configure_logging

spec/unit/dsl/plugin_spec.rb

@@ -587,6 +587,7 @@
     let(:ohai) { Ohai::System.new }
 
     it "logs a debug message when provides is used" do
+      allow(Ohai::Log).to receive(:debug)
       expect(Ohai::Log).to receive(:debug).with(/Skipping provides/)
       plugin = Ohai::DSL::Plugin::VersionVI.new(ohai, "/some/plugin/path.rb", "/some/plugin")
       plugin.provides("attribute")

spec/unit/loader_spec.rb

@@ -219,6 +219,14 @@
           expect { loader.load_plugin(path_to("bad_name.rb")) }.not_to raise_error
         end
       end
+
+      describe "when plugin directory does not exist" do
+        it "logs an invalid plugin path warning" do
+          expect(Ohai::Log).to receive(:warn).with(/The plugin path.*does not exist/)
+          allow(Dir).to receive(:exist?).with("/bogus/dir").and_return(false)
+          Ohai::Loader::PluginFile.find_all_in("/bogus/dir")
+        end
+      end
     end
   end
 end