Parse WhatIf from LCM

5 files changed, 383 insertions, 25 deletions

diff --git a/lib/chef/provider/dsc_script.rb b/lib/chef/provider/dsc_script.rb
index 5cdc37a312..2adb32937f 100644
--- a/lib/chef/provider/dsc_script.rb
+++ b/lib/chef/provider/dsc_script.rb
@@ -38,7 +38,7 @@ class Chef
 
       def action_run
         if ! @resource_converged
-          converge_by("DSC resource script for configuration '#{configuration_friendly_name}'") do
+          converge_by(generate_description) do
             run_configuration(:set)
             Chef::Log.info("DSC resource configuration completed successfully")
           end
@@ -46,7 +46,10 @@ class Chef
       end
 
       def load_current_resource
-        @resource_converged = ! run_configuration(:test)
+        @dsc_resources_info = run_configuration(:test)
+        @resource_converged = @dsc_resources_info.all? do |resource|
+          !resource.changes_state?
+        end
       end
 
       def whyrun_supported?
@@ -98,6 +101,17 @@ class Chef
           configuration_name
         end
       end
+
+      private
+
+      def generate_description
+        ["DSC resource script for configuration '#{configuration_friendly_name}'"] + 
+          @dsc_resources_info.map do |resource|
+            # We ignore the last log message because it only contains the time it took, which looks weird
+            cleaned_messages = resource.change_log[0..-2].map { |c| c.sub(/^#{Regexp.escape(resource.name)}/, '').strip }
+            cleaned_messages.find_all{ |c| c != ''}.join("\n")
+          end
+      end
     end
   end
 end
diff --git a/lib/chef/util/dsc/lcm_output_parser.rb b/lib/chef/util/dsc/lcm_output_parser.rb
new file mode 100644
index 0000000000..420901bcfa
--- /dev/null
+++ b/lib/chef/util/dsc/lcm_output_parser.rb
@@ -0,0 +1,172 @@
+#
+# Author:: Jay Mundrawala (<jdm@getchef.com>)
+#
+# Copyright:: 2014, Chef Software, Inc.
+#
+# 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/util/dsc/resource_info'
+
+class Chef
+  class Util
+    class DSC
+      class LocalConfigurationManager
+        module Parser
+          class ParseException < RuntimeError; end
+
+          class Operation
+            attr_reader :op_type
+            attr_reader :resources
+            attr_reader :info
+            attr_reader :sets
+            attr_reader :tests
+
+            def initialize(op_type, info)
+              @op_type = op_type
+              @info = []
+              @sets = []
+              @tests = []
+              @resources = []
+              add_info(info)
+            end
+
+            def add_info(info)
+              @info << info
+            end
+
+            def add_set(set)
+              raise ParseException, "add_set is not allowed in this context. Found #{@op_type}" unless [:resource, :set].include?(@op_type)
+              @sets << set
+            end
+
+            def add_test(test)
+              raise ParseException, "add_test is not allowed in this context. Found #{@op_type}" unless [:resource, :set].include?(@op_type)
+              @tests << test
+            end
+
+            def add_resource(resource)
+              raise ParseException, 'add_resource is only allowed to be added to the set op_type' unless @op_type == :set
+              @resources << resource
+            end
+          end
+
+          # Parses the output from LCM and returns a list of Chef::Util::DSC::ResourceInfo objects
+          # that describe how the resources affected the system
+          # 
+          # Example:
+          #   parse <<-EOF
+          #   What if: [Machine]: LCM: [Start Set      ]
+          #   What if: [Machine]: LCM: [Start Resource ] [[File]FileToNotBeThere]
+          #   What if: [Machine]: LCM: [Start Set      ] [[File]FileToNotBeThere]
+          #   What if:                                   [C:\ShouldNotExist.txt] removed
+          #   What if: [Machine]: LCM: [End Set        ] [[File]FileToNotBeThere] in 0.1 seconds
+          #   What if: [Machine]: LCM: [End Resource   ] [[File]FileToNotBeThere]
+          #   What if: [Machine]: LCM: [End Set        ]
+          #   EOF
+          #
+          #   would return
+          #
+          #   [
+          #     Chef::Util::DSC::ResourceInfo.new(
+          #       '[[File]FileToNotBeThere]', 
+          #       true, 
+          #       [
+          #         '[[File]FileToNotBeThere]', 
+          #         '[C:\Shouldnotexist.txt]', 
+          #         '[[File]FileToNotBeThere] in 0.1 seconds'
+          #       ]
+          #     )
+          #   ]
+          #
+          def self.parse(lcm_output)
+            return [] unless lcm_output
+
+            stack = Array.new
+            popped_op = nil
+            lcm_output.lines.each do |line|
+              op_action, op_type, info = parse_line(line)
+              info.strip! # Because this was formatted for humans
+
+              # The rules:
+              # - For each `start` action, there must be a matching `end` action
+              # - `skip` actions do not not do anything (They don't add to the stack)
+              case op_action
+              when :start
+                new_op = Operation.new(op_type, info)
+                case op_type
+                when :set
+                  stack[-1].add_set(new_op) if stack[-1]
+                when :test
+                  stack[-1].add_test(new_op)
+                when :resource
+                  stack[-1].add_resource(new_op)
+                else
+                  Chef::Log.warn("Unknown op_action #{op_action}: Read line #{line}")
+                end
+                stack.push(new_op)
+              when :end
+                popped_op = stack.pop
+                popped_op.add_info(info)
+                if popped_op.op_type != op_type
+                  raise LCMOutputParseException, "Unmatching end for op_type. Expected op_type=#{op_type}, found op_type=#{popped_op.op_type}"
+                end
+              when :skip
+                # We don't really have anything to do here
+              when :info
+                stack[-1].add_info(info) if stack[-1]
+              else
+                stack[-1].add_info(line) if stack[-1]
+              end
+            end
+
+            op_to_resource_infos(popped_op)
+          end
+
+          def self.parse_line(line)
+            if match = line.match(/^.*?:.*?:\s*LCM:\s*\[(.*?)\](.*)/)
+                # If the line looks like
+                # x: [y]: LCM: [op_action op_type] message
+                # extract op_action, op_type, and message
+                operation, info = match.captures
+                op_action, op_type = operation.strip.split(' ').map {|m| m.downcase.to_sym}
+            else
+              # If the line looks like
+              # x: [y]: message
+              # extract message
+              match = line.match(/^.*?:.*?: \s+(.*)/)
+              op_action = op_type = :info
+              info = match.captures[0]
+            end
+            info.strip! # Because this was formatted for humans
+            return [op_action, op_type, info]
+          end
+          private_class_method :parse_line
+
+          def self.op_to_resource_infos(op)
+            resources = op ? op.resources : []
+
+            resources.map do |r|
+              name = r.info[0]
+              sets = r.sets.length > 0
+              change_log = r.sets[-1].info if sets
+              Chef::Util::DSC::ResourceInfo.new(name, sets, change_log)
+            end
+          end
+          private_class_method :op_to_resource_infos
+
+        end
+      end
+    end
+  end
+end
diff --git a/lib/chef/util/dsc/local_configuration_manager.rb b/lib/chef/util/dsc/local_configuration_manager.rb
index a9c5b867df..d7d532a686 100644
--- a/lib/chef/util/dsc/local_configuration_manager.rb
+++ b/lib/chef/util/dsc/local_configuration_manager.rb
@@ -17,6 +17,7 @@
 #
 
 require 'chef/util/powershell/cmdlet'
+require 'chef/util/dsc/lcm_output_parser'
 
 class Chef::Util::DSC
   class LocalConfigurationManager
@@ -68,7 +69,8 @@ class Chef::Util::DSC
 
     def configuration_update_required?(what_if_output)
       Chef::Log.debug("DSC: DSC returned the following '-whatif' output from test operation:\n#{what_if_output}")
-      parse_what_if_output(what_if_output)
+      #parse_what_if_output(what_if_output)
+      Parser::parse(what_if_output)
     end
 
     def save_configuration_document(configuration_document)
@@ -86,28 +88,6 @@ class Chef::Util::DSC
       File.join(@configuration_path,'..mof')
     end
 
-    def parse_what_if_output(what_if_output)
-
-      # What-if output for start-dscconfiguration contains lines that look like one of the following:
-      #
-      # What if: [SEA-ADAMED1]: LCM:  [ Start  Set      ]  [[Group]chef_dsc]
-      # What if: [SEA-ADAMED1]:                            [[Group]chef_dsc] Performing the operation "Add" on target "Group: demo1"
-      # 
-      # The second line lacking the 'LCM:' is what happens if there is a change required to make the system consistent with the resource.
-      # Such a line without LCM is only present if an update to the system is required. Therefore, we test each line below
-      # to see if it is missing the LCM, and declare that an update is needed if so.
-      has_change_line = false
-      
-      what_if_output.lines.each do |line|
-        if (line =~ /.+\:\s+\[\S*\]\:\s+LCM\:/).nil?
-          has_change_line = true
-          break
-        end
-      end
-      
-      has_change_line
-    end
-
     def clear_execution_time
       @operation_start_time = nil
       @operation_end_time = nil
diff --git a/lib/chef/util/dsc/resource_info.rb b/lib/chef/util/dsc/resource_info.rb
new file mode 100644
index 0000000000..4a32451721
--- /dev/null
+++ b/lib/chef/util/dsc/resource_info.rb
@@ -0,0 +1,26 @@
+
+class Chef
+  class Util
+    class DSC
+        class ResourceInfo
+          # The name is the text following [Start Set]
+          attr_reader :name
+
+          # A list of all log messages between [Start Set] and [End Set].
+          # Each line is an element in the list.
+          attr_reader :change_log
+
+          def initialize(name, sets, change_log)
+            @name = name
+            @sets = sets
+            @change_log = change_log || []
+          end
+
+          # Does this resource change the state of the system?
+          def changes_state?
+            @sets
+          end
+        end
+    end
+  end
+end
diff --git a/spec/unit/util/dsc/lcm_output_parser_spec.rb b/spec/unit/util/dsc/lcm_output_parser_spec.rb
new file mode 100644
index 0000000000..8ed305827c
--- /dev/null
+++ b/spec/unit/util/dsc/lcm_output_parser_spec.rb
@@ -0,0 +1,166 @@
+#
+# Author:: Bryan McLellan <btm@loftninjas.org>
+# Copyright:: Copyright (c) 2014 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/util/dsc/lcm_output_parser'
+
+describe Chef::Util::DSC::LocalConfigurationManager::Parser do
+  context 'empty input parameter' do
+    it 'returns an emtpy array for a 0 length string' do
+      Chef::Util::DSC::LocalConfigurationManager::Parser::parse('').should be_empty
+    end
+
+    it 'returns an emtpy array for a nil input' do
+      Chef::Util::DSC::LocalConfigurationManager::Parser::parse('').should be_empty
+    end
+  end
+
+  context 'correctly formatted output from lcm' do
+    it 'returns an empty array for a log with no resources' do
+      str = <<EOF
+logtype: [machinename]: LCM:  [ Start  Set      ]
+logtype: [machinename]: LCM:  [ End    Set      ]
+EOF
+      Chef::Util::DSC::LocalConfigurationManager::Parser::parse(str).should be_empty
+    end
+
+    it 'returns a single resource when only 1 logged with the correct name' do
+      str = <<EOF
+logtype: [machinename]: LCM:  [ Start  Set      ]
+logtype: [machinename]: LCM:  [ Start  Resource ] [name]
+logtype: [machinename]: LCM:  [ End    Resource ] [name]
+logtype: [machinename]: LCM:  [ End    Set      ]
+EOF
+      resources = Chef::Util::DSC::LocalConfigurationManager::Parser::parse(str)
+      resources.length.should eq(1)
+      resources[0].name.should eq('[name]')
+    end
+
+    it 'identifies when a resource changes the state of the system' do
+      str = <<EOF
+logtype: [machinename]: LCM:  [ Start  Set      ]
+logtype: [machinename]: LCM:  [ Start  Resource ] [name]
+logtype: [machinename]: LCM:  [ Start  Set      ] [name]
+logtype: [machinename]: LCM:  [ End    Set      ] [name]
+logtype: [machinename]: LCM:  [ End    Resource ] [name]
+logtype: [machinename]: LCM:  [ End    Set      ]
+EOF
+      resources = Chef::Util::DSC::LocalConfigurationManager::Parser::parse(str)
+      resources[0].changes_state?.should be_true
+    end
+
+    it 'preserves the log provided for how the system changed the state' do
+      str = <<EOF
+logtype: [machinename]: LCM:  [ Start  Set      ]
+logtype: [machinename]: LCM:  [ Start  Resource ] [name]
+logtype: [machinename]: LCM:  [ Start  Set      ] [name]
+logtype: [machinename]:                           [message]
+logtype: [machinename]: LCM:  [ End    Set      ] [name]
+logtype: [machinename]: LCM:  [ End    Resource ] [name]
+logtype: [machinename]: LCM:  [ End    Set      ]
+EOF
+      resources = Chef::Util::DSC::LocalConfigurationManager::Parser::parse(str)
+      resources[0].change_log.should match_array(["[name]","[message]","[name]"])
+    end
+
+    it 'should return false for changes_state?' do
+      str = <<EOF
+logtype: [machinename]: LCM:  [ Start  Set      ]
+logtype: [machinename]: LCM:  [ Start  Resource ] [name]
+logtype: [machinename]: LCM:  [ Skip   Set      ] [name]
+logtype: [machinename]: LCM:  [ End    Resource ] [name]
+logtype: [machinename]: LCM:  [ End    Set      ]
+EOF
+      resources = Chef::Util::DSC::LocalConfigurationManager::Parser::parse(str)
+      resources[0].changes_state?.should be_false
+    end
+
+    it 'should return an empty array for change_log if changes_state? is false' do
+      str = <<EOF
+logtype: [machinename]: LCM:  [ Start  Set      ]
+logtype: [machinename]: LCM:  [ Start  Resource ] [name]
+logtype: [machinename]: LCM:  [ Skip   Set      ] [name]
+logtype: [machinename]: LCM:  [ End    Resource ] [name]
+logtype: [machinename]: LCM:  [ End    Set      ]
+EOF
+      resources = Chef::Util::DSC::LocalConfigurationManager::Parser::parse(str)
+      resources[0].change_log.should be_empty
+    end
+  end
+
+  context 'Incorrectly formatted output from LCM' do
+    it 'should raise an exception if a set is found inside a test' do
+      str = <<EOF
+logtype: [machinename]: LCM:  [ Start  Set      ]
+logtype: [machinename]: LCM:  [ Start  Resource ] [name]
+logtype: [machinename]: LCM:  [ Start  Test     ]
+logtype: [machinename]: LCM:  [ Start  Set      ]
+logtype: [machinename]: LCM:  [ End    Set      ]
+logtype: [machinename]: LCM:  [ End    Test     ]
+logtype: [machinename]: LCM:  [ End    Resource ] [name]
+logtype: [machinename]: LCM:  [ End    Set      ]
+EOF
+      expect { Chef::Util::DSC::LocalConfigurationManager::Parser::parse(str) }.to(raise_error(
+        Chef::Util::DSC::LocalConfigurationManager::Parser::ParseException))
+    end
+
+    it 'should raise an exception if a test is found inside a test' do
+      str = <<EOF
+logtype: [machinename]: LCM:  [ Start  Set      ]
+logtype: [machinename]: LCM:  [ Start  Resource ] [name]
+logtype: [machinename]: LCM:  [ Start  Test     ]
+logtype: [machinename]: LCM:  [ Start  Test     ]
+logtype: [machinename]: LCM:  [ End    Test     ]
+logtype: [machinename]: LCM:  [ End    Test     ]
+logtype: [machinename]: LCM:  [ End    Resource ] [name]
+logtype: [machinename]: LCM:  [ End    Set      ]
+EOF
+      expect { Chef::Util::DSC::LocalConfigurationManager::Parser::parse(str) }.to(raise_error(
+        Chef::Util::DSC::LocalConfigurationManager::Parser::ParseException))
+    end
+
+    it 'should raise an exception if a resource is found inside a test' do
+      str = <<EOF
+logtype: [machinename]: LCM:  [ Start  Set      ]
+logtype: [machinename]: LCM:  [ Start  Resource ] [name]
+logtype: [machinename]: LCM:  [ Start  Test     ]
+logtype: [machinename]: LCM:  [ Start  Resource ]
+logtype: [machinename]: LCM:  [ End    Resource  ]
+logtype: [machinename]: LCM:  [ End    Test     ]
+logtype: [machinename]: LCM:  [ End    Resource ] [name]
+logtype: [machinename]: LCM:  [ End    Set      ]
+EOF
+      expect { Chef::Util::DSC::LocalConfigurationManager::Parser::parse(str) }.to(raise_error(
+        Chef::Util::DSC::LocalConfigurationManager::Parser::ParseException))
+    end
+
+    it 'should raise an exception if a resource is found inside a resource' do
+      str = <<EOF
+logtype: [machinename]: LCM:  [ Start  Set      ]
+logtype: [machinename]: LCM:  [ Start  Resource ] [name]
+logtype: [machinename]: LCM:  [ Start  Resource ]
+logtype: [machinename]: LCM:  [ End    Resource  ]
+logtype: [machinename]: LCM:  [ End    Resource ] [name]
+logtype: [machinename]: LCM:  [ End    Set      ]
+EOF
+      expect { Chef::Util::DSC::LocalConfigurationManager::Parser::parse(str) }.to(raise_error(
+        Chef::Util::DSC::LocalConfigurationManager::Parser::ParseException))
+    end
+
+  end
+
+end