Add backup attribute to file resource (close itamae-kitchen#124)

lib/itamae/resource/file.rb

@@ -3,12 +3,15 @@
 module Itamae
   module Resource
     class File < Base
+      BACKUP_PATH = '/var/itamae/backup'.freeze
+
       define_attribute :action, default: :create
       define_attribute :path, type: String, default_name: true
       define_attribute :content, type: String, default: nil
       define_attribute :mode, type: String
       define_attribute :owner, type: String
       define_attribute :group, type: String
+      define_attribute :backup, type: [FalseClass, Integer], default: 5
       define_attribute :block, type: Proc, default: proc {}
 
       def pre_action
@@ -56,6 +59,8 @@ def show_differences
       end
 
       def action_create(options)
+        backup if current.exist
+
         if !current.exist && !@temppath
           run_command(["touch", attributes.path])
         end
@@ -93,6 +98,8 @@ def action_delete(options)
       end
 
       def action_edit(options)
+        backup if current.exist
+
         if attributes.mode
           run_specinfra(:change_file_mode, @temppath, attributes.mode)
         else
@@ -171,6 +178,34 @@ def send_tempfile
           f.unlink if f
         end
       end
+
+      def backup
+        return if !attributes.backup || attributes.backup <= 0
+
+        savetime = Time.now.strftime('%Y%m%d%H%M%S')
+        backup_filename = "#{attributes.path}.itamae-#{savetime}"
+        backup_path = ::File.join(BACKUP_PATH, backup_filename)
+        backup_directory = ::File.dirname(backup_path)
+
+        run_command(['install', '-d', '-m=777', backup_directory])
+        run_command(['cp', '-p', attributes.path, backup_path])
+        Itamae.logger.info "#{attributes.path} backed up to #{backup_path}"
+
+        basename = ::File.basename(attributes.path)
+        backup_files = run_command(['ls', '-1', backup_directory])
+        backup_files = backup_files.stdout.chomp.split("\n").select { |f|
+          f.match(/\A#{basename}.itamae-[0-9]+\z/)
+        }.reverse
+
+        if backup_files.length > attributes.backup
+          remainder = backup_files.slice(attributes.backup..-1)
+          remainder.each do |backup_to_delete|
+            backup_to_delete = ::File.join(backup_directory, backup_to_delete)
+            run_specinfra(:remove_file, backup_to_delete)
+            Itamae.logger.info "#{attributes.path} removed backup at #{backup_to_delete}"
+          end
+        end
+      end
     end
   end
 end

spec/integration/default_spec.rb

@@ -51,9 +51,19 @@
   end
 end
 
+describe file('/var/itamae/backup/tmp') do
+  it { should be_directory }
+  it { should be_mode 777 }
+end
+
+describe command('cat /var/itamae/backup/tmp/file.itamae-*') do
+  its(:stdout) { should match(/Hello World/) }
+  its(:exit_status) { should eq(0) }
+end
+
 describe file('/tmp/file') do
   it { should be_file }
-  its(:content) { should match(/Hello World/) }
+  its(:content) { should match(/Hello New World/) }
   it { should be_mode 777 }
 end
 

spec/integration/recipes/default.rb

@@ -148,6 +148,11 @@
   mode "777"
 end
 
+file "/tmp/file" do
+  content "Hello New World"
+  mode "777"
+end
+
 execute "echo 'Hello Execute' > /tmp/execute"
 
 file "/tmp/never_exist1" do