Box#alive? to check status of a remote box

lib/rush/box.rb

@@ -55,6 +55,11 @@ def bash(command)
 		connection.bash(command)
 	end
 
+	# Returns true if the box is responding to commands.
+	def alive?
+		connection.alive?
+	end
+
 	# This is called automatically the first time an action is invoked, but you
 	# may wish to call it manually ahead of time in order to have the tunnel
 	# already set up and running.

lib/rush/local.rb

@@ -274,4 +274,9 @@ def receive(params)
 	# No-op for duck typing with remote connection.
 	def ensure_tunnel
 	end
+
+	# Local connections are always alive.
+	def alive?
+		true
+	end
 end

lib/rush/remote.rb

@@ -127,6 +127,15 @@ def ensure_tunnel
 		tunnel.ensure_tunnel
 	end
 
+	# Remote connections are alive when the box on the other end is responding
+	# to commands.
+	def alive?
+		index('/', 'alive_check')
+		true
+	rescue
+		false
+	end
+
 	def config
 		@config ||= Rush::Config.new
 	end

spec/box_spec.rb

@@ -26,6 +26,11 @@
 		@box.bash('cmd').should == 'output'
 	end
 
+	it "checks the connection to determine if it is alive" do
+		@box.connection.should_receive(:alive?).and_return(true)
+		@box.should be_alive
+	end
+
 	it "establish_connection to set up the connection manually" do
 		@box.connection.should_receive(:ensure_tunnel)
 		@box.establish_connection

spec/local_spec.rb

@@ -216,4 +216,8 @@
 	it "ensure_tunnel to match with remote connection" do
 		@con.ensure_tunnel
 	end
+
+	it "always returns true on alive?" do
+		@con.should be_alive
+	end
 end

spec/remote_spec.rb

@@ -112,4 +112,14 @@
 		@con.tunnel.should_receive(:ensure_tunnel)
 		@con.ensure_tunnel
 	end
+
+	it "is alive if the box is responding to commands" do
+		@con.should_receive(:index).and_return(:dummy)
+		@con.should be_alive
+	end
+
+	it "not alive if an attempted command throws an exception" do
+		@con.should_receive(:index).and_raise(RuntimeError)
+		@con.should_not be_alive
+	end
 end