Add support for config.command_output

Normally airbrussh hides all stderr and stdout data returned by SSH commands.
With this commit, users of airbrussh can selectively enable displaying of
stderr and/or stdout data.

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 * Your contribution here.
 * New `config.banner` option allows startup message to be disabled or changed (suggestion from [@justindowning](https://github.com/justindowning))
+* New `config.command_output` option gives full control of whether airbrussh shows or hides the stderr and stdout data received from remote commands; see the usage section of the README for further explanation (suggestion from [@carlesso](https://github.com/carlesso))
 
 ## 0.2.1 (2015-03-02)
 

README.md

@@ -53,39 +53,70 @@ Airbrussh automatically replaces the default Capistrano log formatter, so there
 ```ruby
 Airbrussh.configure do |config|
   # Capistrano's default, un-airbrusshed output is saved to a file to
-  # facilitate debugging. To disable this entirely:
+  # facilitate debugging.
+  #
+  # To disable this entirely:
   # config.log_file = nil
+  #
   # Default:
   config.log_file = "log/capistrano.log"
 
   # Airbrussh patches Rake so it can access the name of the currently executing
   # task. Set this to false if monkey patching is causing issues.
+  #
   # Default:
   config.monkey_patch_rake = true
 
   # Ansi colors will be used in the output automatically based on whether the
   # output is a TTY, or if the SSHKIT_COLOR environment variable is set.
+  #
   # To disable color always:
   # config.color = false
+  #
   # Default:
   config.color = :auto
 
   # Output is automatically truncated to the width of the terminal window, if
   # possible. If the width of the terminal can't be determined, no truncation
-  # is performed. To truncate to a fixed width:
+  # is performed.
+  #
+  # To truncate to a fixed width:
   # config.truncate = 80
+  #
   # Or to disable truncation entirely:
   # config.truncate = false
+  #
   # Default:
   config.truncate = :auto
 
   # If a log_file is configured, airbrussh will output a message at startup
-  # displaying the log_file location. To always disable this message:
+  # displaying the log_file location.
+  #
+  # To always disable this message:
   # config.banner = false
+  #
   # To display an alternative message:
   # config.banner = "Hello, world!"
+  #
   # Default:
   config.banner = :auto
+
+  # You can control whether airbrussh shows the output of SSH commands. For
+  # brevity, the output is hidden by default.
+  #
+  # Display stdout of SSH commands. Stderr is not displayed.
+  # config.command_output = :stdout
+  #
+  # Display stderr of SSH commands. Stdout is not displayed.
+  # config.command_output = :stderr
+  #
+  # Display all SSH command output.
+  # config.command_output = [:stdout, :stderr]
+  # or
+  # config.command_output = true
+  #
+  # Default (all output suppressed):
+  config.command_output = false
 end
 ```
 
@@ -107,6 +138,7 @@ Airbrussh.configure do |config|
   config.color = :auto
   config.truncate = :auto
   config.banner = :auto
+  config.command_output = false
 end
 ```
 

lib/airbrussh/configuration.rb

@@ -1,13 +1,29 @@
 module Airbrussh
   class Configuration
-    attr_accessor :log_file, :monkey_patch_rake, :color, :truncate, :banner
+    attr_accessor :log_file, :monkey_patch_rake, :color, :truncate, :banner,
+                  :command_output
 
     def initialize
       self.log_file = nil
       self.monkey_patch_rake = false
       self.color = :auto
       self.truncate = :auto
       self.banner = :auto
+      self.command_output = false
+    end
+
+    def command_output_stdout?
+      command_output_include?(:stdout)
+    end
+
+    def command_output_stderr?
+      command_output_include?(:stderr)
+    end
+
+    private
+
+    def command_output_include?(sym)
+      command_output == true || Array(command_output).include?(sym)
     end
   end
 end

lib/airbrussh/formatter.rb

@@ -33,7 +33,7 @@ def initialize(io)
 
       @tasks = {}
 
-      @log_file = Airbrussh.configuration.log_file
+      @log_file = config.log_file
       @log_file_formatter = create_log_file_formatter
 
       @console = Airbrussh::Console.new(original_output)
@@ -53,13 +53,13 @@ def print_line(string)
     end
 
     def write_banner
-      return unless Airbrussh.configuration.banner
-      if Airbrussh.configuration.banner == :auto
+      return unless config.banner
+      if config.banner == :auto
         return if @log_file.nil?
         print_line "Using airbrussh format."
         print_line "Verbose output is being written to #{blue(@log_file)}."
       else
-        print_line Airbrussh.configuration.banner
+        print_line config.banner
       end
     end
 
@@ -77,7 +77,9 @@ def write_log_file_delimiter
     end
 
     def write(obj)
-      @log_file_formatter << obj
+      # SSHKit's :pretty formatter mutates the stdout and stderr data in the
+      # command obj. So we need to dup it to ensure our copy is unscathed.
+      @log_file_formatter << obj.dup
 
       case obj
       when SSHKit::Command    then write_command(obj)
@@ -119,12 +121,37 @@ def write_command(command)
         print_line "      #{number} #{description}"
       end
 
+      write_command_output(command, number)
+
       if command.finished?
         status = format_command_completion_status(command, number)
         print_line "    #{status}"
       end
     end
 
+    # Prints the data from the stdout and stderr streams of the given command,
+    # but only if enabled (see Airbrussh::Configuration#command_output).
+    def write_command_output(command, number)
+      # Use a bit of meta-programming here, since stderr and stdout logic
+      # are identical except for different method names.
+      %w(stderr stdout).each do |stream|
+
+        next unless config.public_send("command_output_#{stream}?")
+        output = command.public_send(stream)
+        next if output.empty?
+
+        output.lines.each do |line|
+          print_line "      #{number} #{line.chomp}"
+        end
+
+        # The stderr/stdout data provided by the command object is the current
+        # "chunk" as received over the wire. Since there may be more chunks
+        # appended and we don't want to print duplicates, clear the current
+        # data.
+        command.public_send("#{stream}=", "")
+      end
+    end
+
     def print_task_if_changed
       status = current_task_status
 
@@ -202,5 +229,9 @@ def clock
         string.to_s.colorize(color.to_sym)
       end
     end
+
+    def config
+      Airbrussh.configuration
+    end
   end
 end

test/test_configuration.rb

@@ -0,0 +1,48 @@
+require "minitest_helper"
+
+class TestConfiguration < Minitest::Test
+  def setup
+    # Reset any configuration changes done by the tests
+    Airbrussh.reset
+  end
+
+  def test_default_command_output
+    refute(config.command_output)
+  end
+
+  def test_effects_of_command_output_true
+    config.command_output = true
+    assert(config.command_output_stdout?)
+    assert(config.command_output_stderr?)
+  end
+
+  def test_effects_of_command_output_false
+    config.command_output = false
+    refute(config.command_output_stdout?)
+    refute(config.command_output_stderr?)
+  end
+
+  def test_effects_of_command_output_stdout
+    config.command_output = :stdout
+    assert(config.command_output_stdout?)
+    refute(config.command_output_stderr?)
+  end
+
+  def test_effects_of_command_output_stderr
+    config.command_output = :stderr
+    refute(config.command_output_stdout?)
+    assert(config.command_output_stderr?)
+  end
+
+  def test_effects_of_command_output_stdout_stderr
+    config.command_output = [:stdout, :stderr]
+    assert(config.command_output_stdout?)
+    assert(config.command_output_stderr?)
+  end
+
+  private
+
+  def config
+    Airbrussh.configuration
+  end
+end