Allow users to reference resources from dependencies

All resources from deps are added into the control_eval_context used by
the current profile. However, if there is a name conflict, the last
loaded resource wins. The new `require_resource` dsl method allows the
user to do the following:

    require_resource(profile: 'profile_name',
                     resource: 'other',
                    as: 'renamed')

    describe renamed do
      ...
    end

Signed-off-by: Steven Danna <steve@chef.io>

lib/inspec/control_eval_context.rb

@@ -92,6 +92,14 @@ module Inspec
           res
         end
 
+        define_method :add_resource do |name, new_res|
+          resources_dsl.module_exec do
+            define_method name.to_sym do |*args|
+              new_res.new(@backend, name.to_s, *args)
+            end
+          end
+        end
+
         define_method :add_resources do |context|
           self.class.class_eval do
             include context.to_resources_dsl

lib/inspec/dsl.rb

@@ -18,6 +18,15 @@ module Inspec::DSL
   alias require_rules require_controls
   alias include_rules include_controls
 
+  def require_resource(options = {})
+    fail 'You must specify a specific resource name when calling require_resource()' if options[:resource].nil?
+
+    from_profile = options[:profile] || profile_name
+    target_name = options[:as] || options[:resource]
+    res = resource_class(from_profile, options[:resource])
+    add_resource(target_name, res)
+  end
+
   def self.load_spec_files_for_profile(bind_context, opts, &block)
     dependencies = opts[:dependencies]
     profile_id = opts[:profile_id]

lib/inspec/plugins/resource.rb

@@ -72,6 +72,9 @@ module Inspec
       end
 
       # rubocop:enable Lint/NestedMethodDefinition
+      if __resource_registry.key?(name)
+        Inspec::Log.warn("Overwriting resource #{name}. To reference a specific version of #{name} use the resource() method")
+      end
       __resource_registry[name] = cl
     end
   end

lib/inspec/profile.rb

@@ -66,6 +66,7 @@ module Inspec
       @backend = options[:backend] || Inspec::Backend.create(options)
       @source_reader = source_reader
       @tests_collected = false
+      @libraries_loaded = false
       Metadata.finalize(@source_reader.metadata, @profile_id)
       @runner_context = options[:profile_context] || Inspec::ProfileContext.for_profile(self,
                                                                                         @backend,
@@ -125,6 +126,8 @@ module Inspec
     end
 
     def load_libraries
+      return @runner_context if @libraries_loaded
+
       locked_dependencies.each do |d|
         c = d.load_libraries
         @runner_context.add_resources(c)
@@ -135,6 +138,7 @@ module Inspec
       end
 
       @runner_context.load_libraries(libs)
+      @libraries_loaded = true
       @runner_context
     end
 

lib/inspec/profile_context.rb

@@ -17,7 +17,7 @@ module Inspec
                                    'attributes' => attributes })
     end
 
-    attr_reader :attributes, :profile_id, :resource_registry
+    attr_reader :attributes, :profile_id, :resource_registry, :backend
     attr_accessor :rules
     def initialize(profile_id, backend, conf)
       if backend.nil?
@@ -28,7 +28,8 @@ module Inspec
       @backend = backend
       @conf = conf.dup
       @rules = {}
-      @subcontexts = []
+      @control_subcontexts = []
+      @lib_subcontexts = []
       @require_loader = ::Inspec::RequireLoader.new
       @attributes = []
       # A local resource registry that only contains resources defined
@@ -46,7 +47,7 @@ module Inspec
     end
 
     def to_resources_dsl
-      Inspec::Resource.create_dsl(@backend, @resource_registry)
+      Inspec::Resource.create_dsl(self)
     end
 
     def control_eval_context
@@ -66,20 +67,34 @@ module Inspec
       @conf['profile'].supports_os?
     end
 
-    def all_rules
+    def all_controls
       ret = @rules.values
-      ret += @subcontexts.map(&:all_rules).flatten
+      ret += @control_subcontexts.map(&:all_rules).flatten
       ret
     end
+    alias all_rules all_controls
+
+    def subcontext_by_name(name)
+      found = @lib_subcontexts.find { |c| c.profile_id == name }
+      if !found
+        @lib_subcontexts.each do |c|
+          found = c.subcontext_by_name(name)
+          break if found
+        end
+      end
+
+      found
+    end
 
     def add_resources(context)
       @resource_registry.merge!(context.resource_registry)
       control_eval_context.add_resources(context)
+      @lib_subcontexts << context
       reload_dsl
     end
 
     def add_subcontext(context)
-      @subcontexts << context
+      @control_subcontexts << context
     end
 
     def load_libraries(libs)

lib/inspec/resource.rb

@@ -6,6 +6,8 @@
 require 'inspec/plugins'
 
 module Inspec
+  class ProfileNotFound < StandardError; end
+
   class Resource
     def self.default_registry
       @default_registry ||= {}
@@ -25,9 +27,22 @@ module Inspec
     #
     # @param backend [BackendRunner] exposing the target to resources
     # @return [ResourcesDSL]
-    def self.create_dsl(backend, my_registry = registry)
-      # need the local name, to use it in the module creation further down
+    def self.create_dsl(profile_context)
+      backend = profile_context.backend
+      my_registry = profile_context.resource_registry
+
       Module.new do
+        define_method :resource_class do |profile_name, resource_name|
+          inner_context = if profile_name == profile_context.profile_id
+                            profile_context
+                          else
+                            profile_context.subcontext_by_name(profile_name)
+                          end
+
+          fail ProfileNotFound, "Cannot find profile named: #{profile_name}" if inner_context.nil?
+          inner_context.resource_registry[resource_name]
+        end
+
         my_registry.each do |id, r|
           define_method id.to_sym do |*args|
             r.new(backend, id.to_s, *args)

test/functional/inspec_exec_test.rb

@@ -176,6 +176,15 @@ Test Summary: \e[32m2 successful\e[0m, \e[31m0 failures\e[0m, \e[37m0 skipped\e[
     end
   end
 
+  describe 'using namespaced resources' do
+    it 'works' do
+      out = inspec('exec ' + File.join(profile_path, 'dependencies', 'resource-namespace'))
+      out.stderr.must_equal ''
+      out.exit_status.must_equal 0
+      out.stdout.force_encoding(Encoding::UTF_8).must_include "Summary: \e[32m5 successful\e[0m, \e[31m0 failures\e[0m, \e[37m0 skipped\e[0m\n"
+    end
+  end
+
   describe "with a 2-level dependency tree" do
     it 'correctly runs tests from the whole tree' do
       out = inspec('exec ' + File.join(profile_path, 'dependencies', 'inheritance'))

test/unit/mock/profiles/dependencies/resource-namespace/controls/example.rb

@@ -0,0 +1,27 @@
+# encoding: utf-8
+# copyright: 2015, The Authors
+# license: All rights reserved
+require_resource(profile: 'profile_c', resource: 'gordon_config', as: 'gordy_config')
+
+describe gordy_config do
+  its('version') { should eq('1.0') }
+end
+
+control 'whichgordon' do
+  describe gordy_config do
+    its('version') { should eq('1.0') }
+  end
+
+  describe gordon_config do
+    its('version') { should eq('2.0') }
+  end
+
+  describe gordy_config do
+    its('version') { should eq(gordy_config.version) }
+  end
+
+  describe gordon_config do
+    its('version') { should eq(gordon_config.version) }
+  end
+
+end

test/unit/mock/profiles/dependencies/resource-namespace/inspec.yml

@@ -0,0 +1,13 @@
+name: resource-namespace
+title: InSpec Profile
+maintainer: The Authors
+copyright: The Authors
+copyright_email: you@example.com
+license: All Rights Reserved
+summary: An InSpec Compliance Profile
+version: 0.1.0
+depends:
+  - name: profile_a
+    path: '../profile_a'
+  - name: profile_d
+    path: '../profile_d'

test/unit/profiles/control_eval_context_tests.rb

@@ -2,7 +2,6 @@
 # author: Steven Danna
 
 require 'helper'
-require 'rspec/core'
 require 'inspec/control_eval_context'
 
 describe Inspec::ControlEvalContext do
@@ -11,7 +10,6 @@ describe Inspec::ControlEvalContext do
       "wombat"
     end
   end
-  Inspec::Log.level = :debug
 
   let(:control_content) { <<EOF
 control 'foo' do
@@ -44,11 +42,36 @@ EOF
     profile_context.stubs(:current_load).returns({file: "<test content>"})
     eval_context.instance_eval(control_content)
     profile_context.all_rules.each do |rule|
-      # Turn each rule into an example group and run it, none of the example content should raise an
-      # exception
+      # Turn each rule into an example group and run it, none of the
+      # example content should raise an exception
       Inspec::Rule.prepare_checks(rule).each do |m, a, b|
+        # if we require this at the top level, none of the other tests
+        # in this file will run. itsfine.jpg
+        require 'rspec/core'
         RSpec::Core::ExampleGroup.describe(*a, &b).run
       end
     end
   end
+
+  describe "#resource" do
+    let(:resource_dsl) { Inspec::Resource.create_dsl(profile_context) }
+    let(:inner_context) { Inspec::ProfileContext.new('inner-context', backend, {}) }
+    let(:control_content) do <<EOF
+resource('profile_a', 'foobar')
+EOF
+    end
+
+    it "fails if the requested profile can't be found" do
+      assert_raises(Inspec::ProfileNotFound) {
+        eval_context.instance_eval(control_content).must_raise
+      }
+    end
+
+    it "returns the resource from a subcontext" do
+      profile_context.expects(:subcontext_by_name).with('profile_a').returns(inner_context)
+      inner_context.expects(:resource_registry).returns({'foobar' => mock(:new => 'newfoo')})
+      eval_context.instance_eval(control_content).must_equal "newfoo"
+    end
+
+  end
 end