Added $CAPISTRANO:HOST$ placeholder for commands

git-svn-id: http://svn.rubyonrails.org/rails/tools/capistrano@6425 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

CHANGELOG

@@ -1,5 +1,7 @@
 *SVN*
 
+* Added $CAPISTRANO:HOST$ placeholder in commands, which will be replaced with the name of the host on which the command is executing [Jamis Buck]
+
 * Added -e switch to explain specific task. Added -X to extend -x. Made -h much briefer. Added -T to list known tasks. [Jamis Buck]
 
 * Added namespaces for tasks [Jamis Buck]

lib/capistrano/command.rb

@@ -81,8 +81,8 @@ module Capistrano
 
             channel.on_success do |ch|
               logger.trace "executing command", ch[:host] if logger
-              ch.exec command
-              ch.send_data options[:data] if options[:data]
+              ch.exec(replace_placeholders(command, ch))
+              ch.send_data(options[:data]) if options[:data]
             end
 
             channel.on_failure do |ch|
@@ -112,6 +112,10 @@ module Capistrano
         end
       end
 
+      def replace_placeholders(command, channel)
+        command.gsub(/\$CAPISTRANO:HOST\$/, channel[:host])
+      end
+
       # prepare a space-separated sequence of variables assignments
       # intended to be prepended to a command, so the shell sets
       # the environment before running the command.

test/command_test.rb

@@ -214,6 +214,20 @@ class CommandTest < Test::Unit::TestCase
     assert_equal :command, parameter
   end
 
+  def test_process_with_host_placeholder_should_substitute_placeholder_with_each_host
+    session = setup_for_extracting_channel_action(:on_success) do |ch|
+      ch.expects(:exec).with("echo capistrano")
+    end
+    Capistrano::Command.new("echo $CAPISTRANO:HOST$", [session])
+  end
+
+  def test_process_with_unknown_placeholder_should_not_replace_placeholder
+    session = setup_for_extracting_channel_action(:on_success) do |ch|
+      ch.expects(:exec).with("echo $CAPISTRANO:OTHER$")
+    end
+    Capistrano::Command.new("echo $CAPISTRANO:OTHER$", [session])
+  end
+
   private
 
     def new_channel(closed, status=nil)
@@ -232,6 +246,7 @@ class CommandTest < Test::Unit::TestCase
       session.expects(:open_channel).yields(channel)
 
       ch = mock
+      ch.stubs(:[]).with(:host).returns("capistrano")
       channel.expects(action).yields(ch, *args)
 
       yield ch if block_given?