Use tar for intermediate backup storage

During the backup we create an intermediate copy of two directories:
builds and uploads. Instead of creating many small files with 'cp
-r', we now use tar (and fast gzip) to create single intermediate
files. This saves on disk IO and disk space while creating a backup.

1 files changed, 39 insertions, 0 deletions

diff --git a/lib/backup/files.rb b/lib/backup/files.rb
new file mode 100644
index 00000000000..d0a6e8f27be
--- /dev/null
+++ b/lib/backup/files.rb
@@ -0,0 +1,39 @@
+require 'open3'
+
+module Backup
+  class Files
+    attr_reader :name, :app_files_dir, :backup_tarball, :backup_dir, :files_parent_dir
+
+    def initialize(app_files_dir)
+      @app_files_dir = File.realpath(app_files_dir)
+      @name = File.basename(app_files_dir)
+      @files_parent_dir = File.realpath(File.join(@app_files_dir, '..'))
+      @backup_dir = Gitlab.config.backup.path
+      @backup_tarball = File.join(@backup_dir, name + '.tar.gz')
+    end
+
+    # Copy files from public/files to backup/files
+    def dump
+      FileUtils.mkdir_p(Gitlab.config.backup.path)
+      run_pipeline!([%W(tar -C #{files_parent_dir} -cf - #{name}), %W(gzip -c -1)], out: [backup_tarball, 'w', 0600])
+    end
+
+    def restore
+      backup_existing_files_dir
+
+      run_pipeline!([%W(gzip -cd), %W(tar -C #{files_parent_dir} -xf -)], in: backup_tarball)
+    end
+
+    def backup_existing_files_dir
+      timestamped_files_path = File.join(files_parent_dir, "#{name}.#{Time.now.to_i}")
+      if File.exists?(app_files_dir)
+        FileUtils.mv(app_files_dir, File.expand_path(timestamped_files_path))
+      end
+    end
+
+    def run_pipeline!(cmd_list, options={})
+      status_list = Open3.pipeline(*cmd_list, options)
+      abort 'Backup failed' unless status_list.compact.all?(&:success?)
+    end
+  end
+end