Export tarballs of policyfile chef repos

Adds dependency on `minitar` which is dual licensed as GPL or "same
terms as Ruby"; Ruby is multi-licensed with one option being 2-clause
BSD.

chef-dk.gemspec

@@ -41,6 +41,8 @@ Gem::Specification.new do |gem|
   gem.add_dependency "mixlib-shellout", ">= 2.0.0.rc.0", "< 3.0.0"
   gem.add_dependency "ffi-yajl", ">= 1.0", "< 3.0"
 
+  gem.add_dependency "minitar", "~> 0.5.4"
+
   gem.add_dependency "chef", "~> 12.0", ">= 12.2.1"
 
   gem.add_dependency "solve", "~> 2.0", ">= 2.0.1"

lib/chef-dk/command/export.rb

@@ -86,7 +86,7 @@ def initialize(*args)
       def run(params = [])
         return 1 unless apply_params!(params)
         export_service.run
-        ui.msg("Exported policy '#{export_service.policyfile_lock.name}' to #{export_dir}")
+        ui.msg("Exported policy '#{export_service.policyfile_lock.name}' to #{export_target}")
         0
       rescue ExportDirNotEmpty => e
         ui.err("ERROR: " + e.message)
@@ -97,6 +97,14 @@ def run(params = [])
         1
       end
 
+      def export_target
+        if archive?
+          export_service.archive_file_location
+        else
+          export_dir
+        end
+      end
+
       def debug?
         !!config[:debug]
       end

lib/chef-dk/policyfile_services/export_repo.rb

@@ -17,6 +17,9 @@
 
 require 'fileutils'
 require 'tmpdir'
+require 'zlib'
+
+require 'archive/tar/minitar'
 
 require 'chef-dk/service_exceptions'
 require 'chef-dk/policyfile_lock'
@@ -93,7 +96,11 @@ def export
           create_repo_structure
           copy_cookbooks
           create_policyfile_data_item
-          mv_staged_repo
+          if archive?
+            create_archive
+          else
+            mv_staged_repo
+          end
         end
       rescue => error
         msg = "Failed to export policy (in #{policyfile_filename}) to #{export_dir}"
@@ -115,6 +122,14 @@ def with_staging_dir
         end
       end
 
+      def create_archive
+        Zlib::GzipWriter.open(archive_file_location) do |gz_file|
+          Dir.chdir(staging_dir) do
+            Archive::Tar::Minitar.pack(".", gz_file)
+          end
+        end
+      end
+
       def staging_dir
         @staging_dir
       end
@@ -204,7 +219,7 @@ def assert_lockfile_exists!
       end
 
       def assert_export_dir_clean!
-        if !force_export? && !conflicting_fs_entries.empty?
+        if !force_export? && !conflicting_fs_entries.empty? && !archive?
           msg = "Export dir (#{export_dir}) not clean. Refusing to export. (Conflicting files: #{conflicting_fs_entries.join(', ')})"
           raise ExportDirNotEmpty, msg
         end

spec/unit/policyfile_services/export_repo_spec.rb

@@ -192,7 +192,6 @@
           before do
             allow(export_service.policyfile_lock).to receive(:validate_cookbooks!).and_return(true)
             export_service.run
-            pp :export_run
           end
 
           let(:cookbook_files) do
@@ -342,18 +341,54 @@
 
           let(:archive) { true }
 
-          # TODO:
-          it "exports the repo as a tgz archive"
+          let(:expected_archive_path) do
+            File.join(export_dir, "install-example-60e5ad638dce219d8f87d589463ec4a9884007ba5e2adbb4c0a7021d67204f1a.tgz")
+          end
+
+          it "exports the repo as a tgz archive" do
+            expect(File).to exist(expected_archive_path)
+          end
 
           include_examples "successful_export" do
 
+            # explode the tarball so the assertions can find the files
             before do
-              pp :archive_before_block
+              Zlib::GzipReader.open(expected_archive_path) do |gz_file|
+                tar = Archive::Tar::Minitar::Input.new(gz_file)
+                tar.each do |e|
+                  tar.extract_entry(export_dir, e)
+                end
+              end
             end
 
           end
 
-        end
+          context "when the target dir has a cookbooks or data_bags dir" do
+
+            let(:cookbooks_dir) { File.join(export_dir, "cookbooks") }
+
+            let(:file_in_cookbooks_dir) { File.join(cookbooks_dir, "some_random_cruft") }
+
+            let(:policyfiles_data_bag_dir) { File.join(export_dir, "data_bags", "policyfiles") }
+
+            let(:extra_policyfile_data_item) { File.join(policyfiles_data_bag_dir, "leftover-policy.json") }
+
+            before do
+              FileUtils.mkdir_p(export_dir)
+              FileUtils.mkdir_p(cookbooks_dir)
+              FileUtils.mkdir_p(policyfiles_data_bag_dir)
+              File.open(file_in_cookbooks_dir, "wb+") { |f| f.print "some random cruft" }
+              File.open(extra_policyfile_data_item, "wb+") { |f| f.print "some random cruft" }
+            end
+
+            it "exports successfully" do
+              expect { export_service.run }.to_not raise_error
+              expect(File).to exist(expected_archive_path)
+            end
+
+          end
+
+        end # when archive mode is enabled
 
       end # copying the cookbooks to the export dir
     end