Add ohai config context and deprecate top-level config.

6 files changed, 331 insertions, 19 deletions

diff --git a/Gemfile b/Gemfile
index 596b850b..20ed5cd2 100644
--- a/Gemfile
+++ b/Gemfile
@@ -8,6 +8,6 @@ group :development do
   gem "sigar", :platform => "ruby"
   gem 'plist'
 
-  # gem 'pry-debugger'
+  # gem 'pry-byebug'
   # gem 'pry-stack_explorer'
 end
diff --git a/lib/ohai/application.rb b/lib/ohai/application.rb
index 477b4a6f..264df0f2 100644
--- a/lib/ohai/application.rb
+++ b/lib/ohai/application.rb
@@ -74,9 +74,10 @@ class Ohai::Application
     @attributes = parse_options
     @attributes = nil if @attributes.empty?
 
-    Ohai::Config.merge!(config)
-    if Ohai::Config[:directory]
-      Ohai::Config[:plugin_path] << Ohai::Config[:directory]
+    Ohai::Config.merge_deprecated_config
+    Ohai.config.merge!(config)
+    if Ohai.config[:directory]
+      Ohai.config[:plugin_path] << Ohai.config[:directory]
     end
   end
 
diff --git a/lib/ohai/config.rb b/lib/ohai/config.rb
index 4c51e08a..988c2328 100644
--- a/lib/ohai/config.rb
+++ b/lib/ohai/config.rb
@@ -1,6 +1,7 @@
 #
 # Author:: Adam Jacob (<adam@opscode.com>)
-# Copyright:: Copyright (c) 2008 Opscode, Inc.
+# Author:: Claire McQuin (<claire@chef.io>)
+# Copyright:: Copyright (c) 2008-2015 Chef Software, Inc.
 # License:: Apache License, Version 2.0
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -16,28 +17,109 @@
 # limitations under the License.
 #
 
-require 'mixlib/config'
 require 'ohai/log'
+require 'chef-config/logger'
+
+ChefConfig::Logger = Ohai::Log
+
+require 'chef-config/config'
 
 module Ohai
+  Config = ChefConfig::Config
+
+  # Reopens ChefConfig::Config to add Ohai configuration settings.
+  # see: https://github.com/chef/chef/blob/master/lib/chef/config.rb
   class Config
-    extend Mixlib::Config
-
-    # from chef/config.rb, should maybe be moved to mixlib-config?
-    def self.platform_specific_path(path)
-      if RUBY_PLATFORM =~ /mswin|mingw|windows/
-        # turns /etc/chef/client.rb into C:/chef/client.rb
-        path = File.join(ENV['SYSTEMDRIVE'], path.split('/')[2..-1])
-        # ensure all forward slashes are backslashes
-        path.gsub!(File::SEPARATOR, (File::ALT_SEPARATOR || '\\'))
+    # These methods need to be defined before they are used as config defaults,
+    # otherwise they will get method_missing'd to nil.
+    private
+    def self.default_hints_path
+      [ platform_specific_path('/etc/chef/ohai/hints') ]
+    end
+
+    def self.default_plugin_path
+      [ File.expand_path(File.join(File.dirname(__FILE__), 'plugins')) ]
+    end
+
+    public
+    # Copy deprecated configuration options into the ohai config context.
+    def self.merge_deprecated_config
+      [ :hints_path, :plugin_path ].each do |option|
+        if has_key?(option) && send(option) != send("default_#{option}".to_sym)
+          Ohai::Log.warn(option_deprecated(option))
+        end
       end
-      path
+
+      ohai.merge!(configuration)
     end
 
+    # Keep "old" config defaults around so anyone calling Ohai::Config[:key]
+    # won't be broken. Also allows users to append to configuration options
+    # (e.g., Ohai::Config[:plugin_path] << some_path) in their config files.
+    default :disabled_plugins, []
+    default :hints_path, default_hints_path
     default :log_level, :info
     default :log_location, STDERR
-    default :plugin_path, [ File.expand_path(File.join(File.dirname(__FILE__), 'plugins'))]
-    default :disabled_plugins, []
-    default(:hints_path) { [ platform_specific_path('/etc/chef/ohai/hints') ] }
+    default :plugin_path, default_plugin_path
+
+    # Log deprecation warning when a top-level configuration option is set.
+    # TODO: Should we implement a config_attr_reader so that deprecation
+    # warnings will be generatd on read?
+    [
+      :directory,
+      :disabled_plugins,
+      :log_level,
+      :log_location,
+      :version
+    ].each do |option|
+      # https://docs.chef.io/config_rb_client.html#ohai-settings
+      # hints_path and plugin_path are intentionally excluded here; warnings for
+      # setting these attributes are generated in merge_deprecated_config since
+      # append (<<) operations bypass the config writer.
+      config_attr_writer option do |value|
+        # log_level and log_location are common configuration options for chef
+        # and other chef applications. When configuration files are read there
+        # is no distinction between log_level and Ohai::Config[:log_level] and
+        # we may emit a false deprecation warning. The deprecation warnings for
+        # these settings reflect that possibility.
+        # Furthermore, when the top-level config settings are removed we will
+        # need to ensure that Ohai.config[:log_level] can be set by writing
+        # log_level in a configuration file for consistent behavior with chef.
+        deprecation_warning = [ :log_level, :log_location ].include?(value) ?
+          option_might_be_deprecated(option) : option_deprecated(option)
+        Ohai::Log.warn(deprecation_warning)
+        value
+      end
+    end
+
+    config_context :ohai do
+      default :disabled_plugins, []
+      default :hints_path, Ohai::Config.default_hints_path
+      default :log_level, :info
+      default :log_location, STDERR
+      default :plugin_path, Ohai::Config.default_plugin_path
+    end
+
+    private
+    def self.option_deprecated(option)
+      <<-EOM.chomp!.gsub("\n", " ")
+Ohai::Config[:#{option}] is set. Ohai::Config[:#{option}] is deprecated and will
+be removed in future releases of ohai. Use ohai.#{option} in your configuration
+file to configure :#{option} for ohai.
+EOM
+    end
+
+    def self.option_might_be_deprecated(option)
+      option_deprecated(option) + <<-EOM.chomp!.gsub("\n", " ")
+ If your configuration file is used with other applications which configure
+:#{option}, and you have not configured Ohai::Config[:#{option}], you may
+disregard this warning.
+EOM
+    end
+  end
+
+  # Shortcut for Ohai::Config.ohai
+  def self.config
+    Config::ohai
   end
 end
diff --git a/ohai.gemspec b/ohai.gemspec
index 8760f1ce..359e456f 100644
--- a/ohai.gemspec
+++ b/ohai.gemspec
@@ -25,6 +25,7 @@ Gem::Specification.new do |s|
   s.add_dependency "ipaddress"
   s.add_dependency "wmi-lite", "~> 1.0"
   s.add_dependency "ffi", "~> 1.9"
+  s.add_dependency "chef-config", "~> 12.4"
 
   s.add_dependency "rake", "~> 10.1"
   s.add_development_dependency "rspec-core", "~> 3.0"
diff --git a/spec/unit/application_spec.rb b/spec/unit/application_spec.rb
new file mode 100644
index 00000000..32b6f8e1
--- /dev/null
+++ b/spec/unit/application_spec.rb
@@ -0,0 +1,88 @@
+#
+# Author:: Claire McQuin <claire@chef.io>
+# Copyright:: Copyright (c) 2015 Chef Software, Inc.
+# License:: Apache License, Version 2.0
+#
+# 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.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+require_relative '../spec_helper'
+
+require 'ohai/application'
+
+RSpec.describe 'Ohai::Application' do
+
+  let(:argv) { [] }
+  let(:app) { Ohai::Application.new }
+
+  before(:each) do
+    @original_argv = ARGV
+    ARGV.replace(argv)
+  end
+
+  after(:each) do
+    ARGV.replace(@original_argv)
+  end
+
+  describe '#configure_ohai' do
+    it 'merges deprecated config settings into the ohai config context' do
+      expect(Ohai::Config).to receive(:merge_deprecated_config)
+      app.configure_ohai
+    end
+
+    context 'when CLI options are provided' do
+      let(:argv) { [ '-d', directory ] }
+      let(:directory) { '/some/fantastic/plugins' }
+
+      it 'does not generate deprecated config warnings for cli options' do
+        expect(Ohai::Log).to_not receive(:warn).
+          with(/Ohai::Config\[:directory\] is deprecated/)
+        app.configure_ohai
+      end
+
+      it 'merges CLI options into the ohai config context' do
+        app.configure_ohai
+        expect(Ohai.config[:directory]).to eq(directory)
+      end
+    end
+
+    context 'when directory is configured' do
+      let(:directory) { '/some/fantastic/plugins' }
+
+      shared_examples_for 'directory' do
+        it 'adds directory to plugin_path' do
+          app.configure_ohai
+          expect(Ohai.config[:plugin_path]).to include(directory)
+        end
+      end
+
+      context 'in a configuration file' do
+        before do
+          allow(Ohai::Log).to receive(:warn).
+            with(/Ohai::Config\[:directory\] is deprecated/)
+          Ohai::Config[:directory] = directory
+        end
+
+        include_examples 'directory'
+      end
+
+      context 'as a command line option' do
+        let(:argv) { ['-d', directory] }
+
+        include_examples 'directory'
+      end
+    end
+
+  end
+
+end
diff --git a/spec/unit/config_spec.rb b/spec/unit/config_spec.rb
new file mode 100644
index 00000000..52538cab
--- /dev/null
+++ b/spec/unit/config_spec.rb
@@ -0,0 +1,140 @@
+#
+# Author:: Claire McQuin (<claire@chef.io>)
+# Copyright:: Copyright (c) 2015 Chef Software, Inc.
+# License:: Apache License, Version 2.0
+#
+# 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.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+require_relative '../spec_helper'
+
+require 'ohai/config'
+
+RSpec.describe Ohai::Config do
+
+  describe "top-level configuration options" do
+    shared_examples_for "option" do
+      it "logs a deprecation warning and sets the value" do
+        expect(Ohai::Log).to receive(:warn).
+          with(/Ohai::Config\[:#{option}\] is deprecated/)
+        Ohai::Config[option] = value
+        expect(Ohai::Config[option]).to eq(value)
+      end
+    end
+
+    shared_examples_for "appendable option" do
+      it "sets the value" do
+        expect(Ohai::Log).to_not receive(:warn)
+        Ohai::Config[option] << value
+        expect(Ohai::Config[option]).to include(value)
+      end
+    end
+
+    describe ":directory" do
+      include_examples "option" do
+        let(:option) { :directory }
+        let(:value)  { "/some/fantastic/plugins" }
+      end
+    end
+
+    describe ":disabled_plugins" do
+      include_examples "option" do
+        let(:option) { :disabled_plugins }
+        let(:value)  { [ :Foo, :Baz ] }
+      end
+    end
+
+    describe ":hints_path" do
+      include_examples "appendable option" do
+        let(:option) { :hints_path }
+        let(:value)  { "/some/helpful/hints" }
+      end
+    end
+
+    describe ":log_level" do
+      include_examples "option" do
+        let(:option) { :log_level }
+        let(:value)  { :cheese }
+      end
+    end
+
+    describe ":log_location" do
+      include_examples "option" do
+        let(:option) { :log_location }
+        let(:value)  { "/etc/chef/cache/loooogs" }
+      end
+    end
+
+    describe ":plugin_path" do
+      include_examples "appendable option" do
+        let(:option) { :plugin_path }
+        let(:value)  { "/some/fantastic/plugins" }
+      end
+    end
+
+    describe ":version" do
+      include_examples "option" do
+        let(:option) { :version }
+        let(:value)  { "8.2.0" }
+      end
+    end
+  end
+
+  describe "::merge_deprecated_config" do
+    before(:each) do
+      allow(Ohai::Log).to receive(:warn)
+      configure_ohai
+    end
+
+    def configure_ohai
+      Ohai::Config[:directory] = "/some/fantastic/plugins"
+      Ohai::Config[:disabled_plugins] = [ :Foo, :Baz ]
+      Ohai::Config[:log_level] = :debug
+    end
+
+    it "merges top-level config values into the ohai config context" do
+      Ohai::Config.merge_deprecated_config
+      expect(Ohai::Config.ohai.configuration).to eq (Ohai::Config.configuration)
+    end
+
+    shared_examples_for "delayed warn" do
+      it "logs a deprecation warning and merges the value" do
+        expect(Ohai::Log).to receive(:warn).
+          with(/Ohai::Config\[:#{option}\] is deprecated/)
+        Ohai::Config[option] << value
+        Ohai::Config.merge_deprecated_config
+        expect(Ohai::Config.ohai[option]).to include(value)
+      end
+    end
+
+    context "when :hints_path is set" do
+      include_examples "delayed warn" do
+        let(:option) { :hints_path }
+        let(:value)  { "/some/helpful/hints" }
+      end
+    end
+
+    context "when :plugin_path is set" do
+      include_examples "delayed warn" do
+        let(:option) { :plugin_path }
+        let(:value)  { "/some/fantastic/plugins" }
+      end
+    end
+  end
+
+  describe "Ohai.config" do
+    it "returns the ohai config context" do
+      expect(Ohai.config).to eq(Ohai::Config.ohai)
+    end
+  end
+end