Box#repackage to repackage a box.

lib/vagrant/box.rb

@@ -1,4 +1,10 @@
+require 'fileutils'
+
+require 'archive/tar/minitar'
 require "json"
+require "log4r"
+
+require "vagrant/util/platform"
 
 module Vagrant
   # Represents a "box," which is a package Vagrant environment that is used
@@ -38,6 +44,8 @@ module Vagrant
       @provider  = provider
       @directory = directory
       @metadata  = JSON.parse(directory.join("metadata.json").read)
+
+      @logger = Log4r::Logger.new("vagrant::box")
     end
 
     # This deletes the box. This is NOT undoable.
@@ -52,6 +60,41 @@ module Vagrant
       return true
     end
 
+    # This repackages this box and outputs it to the given path.
+    #
+    # @param [Pathname] path The full path (filename included) of where
+    #   to output this box.
+    # @return [Boolean] true if this succeeds.
+    def repackage(path)
+      @logger.debug("Repackaging box '#{@name}' to: #{path}")
+
+      path.open(Util::Platform.tar_file_options) do |f|
+        Archive::Tar::Minitar::Output.open(f) do |output|
+          # Store the current working directory since we need to change
+          # for the tar library.
+          current_dir = FileUtils.pwd
+
+          begin
+            FileUtils.cd(@directory)
+
+            # Find all the files in our current directory and tar it up!
+            Dir.glob(File.join(".", "**", "*")).each do |entry|
+              @logger.debug("Packing file: #{entry}")
+              Archive::Tar::Minitar.pack_file(entry, output)
+            end
+          ensure
+            # Make sure we always cd back into our previous working
+            # directory.
+            FileUtils.cd(current_dir)
+          end
+        end
+      end
+
+      @logger.info("Repackaged box '#{@name}' successfully: #{path}")
+
+      true
+    end
+
     # Implemented for comparison with other boxes. Comparison is
     # implemented by comparing names and providers.
     def <=>(other)

test/unit/support/isolated_environment.rb

@@ -3,6 +3,7 @@ require "pathname"
 require "tempfile"
 
 require "archive/tar/minitar"
+require "json"
 require "log4r"
 
 require "vagrant/util/platform"
@@ -73,7 +74,9 @@ module Unit
       # Create a metadata.json file
       box_metadata_file = box_dir.join("metadata.json")
       box_metadata_file.open("w") do |f|
-        f.write("{}")
+        f.write(JSON.generate({
+          :provider => provider.to_s
+        }))
       end
 
       # Create a Vagrantfile

test/unit/vagrant/box_test.rb

@@ -7,6 +7,8 @@ describe Vagrant::Box do
 
   let(:environment)   { isolated_environment }
 
+  let(:box_collection) { Vagrant::BoxCollection.new(environment.boxes_dir) }
+
   let(:name)          { "foo" }
   let(:provider)      { :virtualbox }
   let(:directory)     { environment.box2("foo", :virtualbox) }
@@ -60,6 +62,27 @@ describe Vagrant::Box do
     end
   end
 
+  describe "repackaging" do
+    it "should repackage the box" do
+      test_file_contents = "hello, world!"
+
+      # Put a file in the box directory to verify it is packaged properly
+      # later.
+      directory.join("test_file").open("w") do |f|
+        f.write(test_file_contents)
+      end
+
+      # Repackage our box to some temporary directory
+      box_output_path = temporary_dir.join("package.box")
+      instance.repackage(box_output_path).should be
+
+      # Let's now add this box again under a different name, and then
+      # verify that we get the proper result back.
+      new_box = box_collection.add(box_output_path, "foo2")
+      new_box.directory.join("test_file").read.should == test_file_contents
+    end
+  end
+
   describe "comparison and ordering" do
     it "should be equal if the name and provider match" do
       a = described_class.new("a", :foo, directory)