Improve `sh' task action error handling:

Handle exit status code in Remote#execute.

features/actions/sh.feature

@@ -24,3 +24,16 @@ Feature: sh task action
       """
     When I execute the recipe
     Then the output must contain "from remote"
+
+  Scenario: aborts on failed command execution
+    Given a recipe with:
+      """
+      target 'some_host.test'
+
+      task :some_task do
+        sh '\false'
+        sh '\echo after_fail'
+      end
+      """
+    When I execute the recipe
+    Then the output must not contain "after_fail"

lib/producer/core/errors.rb

@@ -4,5 +4,6 @@ module Producer
     ConditionNotMetError        = Class.new(Error)
     RecipeEvaluationError       = Class.new(StandardError)
     TaskEvaluationError         = Class.new(RecipeEvaluationError)
+    RemoteCommandExecutionError = Class.new(Error)
   end
 end

lib/producer/core/remote.rb

@@ -16,9 +16,18 @@ module Producer
 
       def execute(command)
         output = ''
-        session.exec command do |ch, stream, data|
+        session.open_channel do |channel|
+          channel.exec command do |ch, success|
+            ch.on_data do |c, data|
               output << data
             end
+
+            ch.on_request('exit-status') do |c, data|
+              exit_status = data.read_long
+              raise RemoteCommandExecutionError if exit_status != 0
+            end
+          end
+        end
         session.loop
         output
       end

spec/producer/core/remote_spec.rb

@@ -49,6 +49,16 @@ module Producer::Core
         end
         expect(remote.execute(command)).to eq arguments
       end
+
+      it 'raises an exception when the exit status code is not 0' do
+        story_with_new_channel do |ch|
+          ch.sends_exec command
+          ch.gets_data arguments
+          ch.gets_exit_status 1
+        end
+        expect { remote.execute(command) }
+          .to raise_error(RemoteCommandExecutionError)
+      end
     end
   end
 end