Add Dynamic PolicyBuilder to switch on policyfile mode

Now we need to switch PolicyBuilder implementations based on several
factors instead of just a single config settings, including content of
the node fetched from the Chef Server.

2 files changed, 137 insertions, 0 deletions

diff --git a/lib/chef/policy_builder.rb b/lib/chef/policy_builder.rb
index 136b2853b0..036d8bc051 100644
--- a/lib/chef/policy_builder.rb
+++ b/lib/chef/policy_builder.rb
@@ -18,6 +18,7 @@
 
 require 'chef/policy_builder/expand_node_object'
 require 'chef/policy_builder/policyfile'
+require 'chef/policy_builder/dynamic'
 
 class Chef
 
diff --git a/lib/chef/policy_builder/dynamic.rb b/lib/chef/policy_builder/dynamic.rb
new file mode 100644
index 0000000000..e976ddd87f
--- /dev/null
+++ b/lib/chef/policy_builder/dynamic.rb
@@ -0,0 +1,136 @@
+#
+# Author:: Daniel DeLeo (<dan@chef.io>)
+# Copyright:: Copyright 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 'chef/log'
+require 'chef/rest'
+require 'chef/run_context'
+require 'chef/config'
+require 'chef/node'
+
+class Chef
+  module PolicyBuilder
+
+    # PolicyBuilder that selects either a Policyfile or non-Policyfile
+    # implementation based on the content of the node object.
+    class Dynamic
+
+      attr_reader :node
+      attr_reader :node_name
+      attr_reader :ohai_data
+      attr_reader :json_attribs
+      attr_reader :override_runlist
+      attr_reader :events
+
+      def initialize(node_name, ohai_data, json_attribs, override_runlist, events)
+        @implementation = nil
+
+        @node_name = node_name
+        @ohai_data = ohai_data
+        @json_attribs = json_attribs
+        @override_runlist = override_runlist
+        @events = events
+
+        @node = nil
+      end
+
+      ## PolicyBuilder API ##
+
+      # Loads the node state from the server, then picks the correct
+      # implementation class based on the node and json_attribs.
+      def load_node
+        events.node_load_start(node_name, config)
+        Chef::Log.debug("Building node object for #{node_name}")
+
+        node = Chef::Node.find_or_create(node_name)
+        select_implementation(node)
+        implementation.finish_load_node(node)
+        node
+      rescue Exception => e
+        events.node_load_failed(node_name, e, config)
+        raise
+      end
+
+      ## Delegated Methods ##
+
+      def original_runlist
+        implementation.original_runlist
+      end
+
+      def run_context
+        implementation.run_context
+      end
+
+      def run_list_expansion
+        implementation.run_list_expansion
+      end
+
+      def build_node
+        implementation.build_node
+      end
+
+      def setup_run_context(specific_recipes=nil)
+        implementation.setup_run_context(specific_recipes)
+      end
+
+      def expand_run_list
+        implementation.expand_run_list
+      end
+
+      def sync_cookbooks
+        implementation.sync_cookbooks
+      end
+
+      def temporary_policy?
+        implementation.temporary_policy?
+      end
+
+      ## Internal Public API ##
+
+      def implementation
+        @implementation
+      end
+
+      def select_implementation(node)
+        if policyfile_set_in_config? || policyfile_attribs_in_node_json? || node_has_policyfile_attrs?(node)
+          @implementation = Policyfile.new(node_name, ohai_data, json_attribs, override_runlist, events)
+        else
+          @implementation = ExpandNodeObject.new(node_name, ohai_data, json_attribs, override_runlist, events)
+        end
+      end
+
+      def config
+        Chef::Config
+      end
+
+      private
+
+      def node_has_policyfile_attrs?(node)
+        node.policy_name || node.policy_group
+      end
+
+      def policyfile_attribs_in_node_json?
+        json_attribs.key?("policy_name") || json_attribs.key?("policy_group")
+      end
+
+      def policyfile_set_in_config?
+        config[:use_policyfile] || config[:policy_name] || config[:policy_group]
+      end
+
+    end
+  end
+end