From e473325de679718ab0695d4d3177eeeef20dc994 Mon Sep 17 00:00:00 2001
From: Jay Mundrawala <jdmundrawala@gmail.com>
Date: Thu, 4 Sep 2014 12:05:25 -0700
Subject: DscScript resource will raise an error if dsc is not available

---
 lib/chef/exceptions.rb             |  2 ++
 lib/chef/platform/query_helpers.rb |  6 +++++-
 lib/chef/resource/dsc_script.rb    | 19 ++++++++++++++++++-
 3 files changed, 25 insertions(+), 2 deletions(-)

(limited to 'lib')

diff --git a/lib/chef/exceptions.rb b/lib/chef/exceptions.rb
index ea053cae64..7298f1f4d1 100644
--- a/lib/chef/exceptions.rb
+++ b/lib/chef/exceptions.rb
@@ -181,6 +181,8 @@ class Chef
 
     class ChildConvergeError < RuntimeError; end
 
+    class NoProviderAvailable < RuntimeError; end
+
     class MissingRole < RuntimeError
       NULL = Object.new
 
diff --git a/lib/chef/platform/query_helpers.rb b/lib/chef/platform/query_helpers.rb
index f6f5309de5..334ab278d1 100644
--- a/lib/chef/platform/query_helpers.rb
+++ b/lib/chef/platform/query_helpers.rb
@@ -45,7 +45,11 @@ class Chef
 
         is_server_2003
       end
-    end
 
+      def supports_dsc?(node)
+        node[:languages] && node[:languages][:powershell] &&
+          node[:languages][:powershell][:version].to_i >= 4
+      end
+    end
   end
 end
diff --git a/lib/chef/resource/dsc_script.rb b/lib/chef/resource/dsc_script.rb
index 37546c3b6a..2972ace1aa 100644
--- a/lib/chef/resource/dsc_script.rb
+++ b/lib/chef/resource/dsc_script.rb
@@ -16,6 +16,8 @@
 # limitations under the License.
 #
 
+require 'chef/exceptions'
+
 class Chef
   class Resource
     class DscScript < Chef::Resource
@@ -26,7 +28,12 @@ class Chef
         super
         @allowed_actions.push(:run)
         @action = :run
-        provider(Chef::Provider::DscScript)
+        if(run_context && Chef::Platform.supports_dsc?(run_context.node))
+          @provider = Chef::Provider::DscScript
+        else
+          raise Chef::Exceptions::NoProviderAvailable,
+            "#{powershell_info_str(run_context)}\nPowershell 4.0 or higher was not detected on your system and is required to use the dsc_script resource."
+        end
       end
 
       def code(arg=nil)
@@ -118,6 +125,16 @@ class Chef
           :kind_of => [ Integer ]
         )
       end
+
+      private
+
+      def powershell_info_str(run_context)
+        if run_context && run_context.node[:languages] && run_context.node[:languages][:powershell]
+            install_info = "Powershell #{run_context.node[:languages][:powershell][:version]} was found on the system."
+          else
+            install_info = 'Powershell was not found.'
+          end
+      end
     end
   end
 end
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