Add support for tarballing up directories to send along to the hosts

blimpy.gemspec

@@ -17,4 +17,5 @@ Gem::Specification.new do |gem|
 
   gem.add_dependency 'fog'
   gem.add_dependency 'thor'
+  gem.add_dependency 'minitar'
 end

lib/blimpy/livery.rb

@@ -0,0 +1,31 @@
+require 'rubygems'
+require 'zlib'
+require 'archive/tar/minitar'
+
+module Blimpy
+  class Livery
+    def self.tarball_directory(directory)
+      if directory.nil? || !(File.directory? directory)
+        raise ArgumentError, "The argument '#{directory}' doesn't appear to be a directory"
+      end
+
+      directory = File.expand_path(directory)
+      short_name = File.basename(directory)
+
+      Dir.chdir(File.expand_path(directory  + '/../')) do
+        self.gzip_for_directory(short_name, '/tmp') do |tgz|
+          Archive::Tar::Minitar.pack(short_name, tgz)
+        end
+      end
+    end
+
+    private
+
+    def self.gzip_for_directory(directory, root)
+      filename = File.join(root, "#{directory}.tar.gz")
+      yield Zlib::GzipWriter.new(File.open(filename, 'wb'))
+      filename
+    end
+
+  end
+end

spec/blimpy/livery_spec.rb

@@ -0,0 +1,19 @@
+require 'spec_helper'
+require 'blimpy/livery'
+
+describe Blimpy::Livery do
+  context 'class methods' do
+    describe '#tarball_directory' do
+      subject { Blimpy::Livery } # No instantiating!
+      it 'should raise an exception if the directory doesn\'t exist' do
+        expect {
+          subject.tarball_directory(nil)
+        }.to raise_error(ArgumentError)
+
+        expect {
+          subject.tarball_directory('/tmp/never-gonna-give-you-up.lolz')
+        }.to raise_error(ArgumentError)
+      end
+    end
+  end
+end