Merge branch '23718/backup-rake-task-human-readable' into 'master'

23718/backup rake task human readable

## What does this MR do?
Add the human readable format to the backup tar file. 
From `1477317140_gitlab_backup.tar` to `1477317140_2016_10_24_gitlab_backup.tar`.

## Are there points in the code the reviewer needs to double check?

## Why was this MR needed?
#23718 issue
## Screenshots (if relevant)

## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG.md) entry added
- [x] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [x] API support added
- Tests
  - [x] Added for this feature/bug
  - [x] All builds are passing
- [x] Conform by the [merge request performance guides](http://docs.gitlab.com/ce/development/merge_request_performance_guidelines.html)
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if it does - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

## What are the relevant issue numbers?
23718

See merge request !7188

1 files changed, 11 insertions, 7 deletions

diff --git a/lib/backup/manager.rb b/lib/backup/manager.rb
index 0dfffaf0bc6..96c20100541 100644
--- a/lib/backup/manager.rb
+++ b/lib/backup/manager.rb
@@ -14,7 +14,7 @@ module Backup
       s[:gitlab_version]     = Gitlab::VERSION
       s[:tar_version]        = tar_version
       s[:skipped]            = ENV["SKIP"]
-      tar_file = "#{s[:backup_created_at].to_i}_gitlab_backup.tar"
+      tar_file = s[:backup_created_at].strftime('%s_%Y_%m_%d') + '_gitlab_backup.tar'
 
       Dir.chdir(Gitlab.config.backup.path) do
         File.open("#{Gitlab.config.backup.path}/backup_information.yml",
@@ -83,10 +83,14 @@ module Backup
 
         Dir.chdir(Gitlab.config.backup.path) do
           file_list = Dir.glob('*_gitlab_backup.tar')
-          file_list.map! { |f| $1.to_i if f =~ /(\d+)_gitlab_backup.tar/ }
-          file_list.sort.each do |timestamp|
-            if Time.at(timestamp) < (Time.now - keep_time)
-              if Kernel.system(*%W(rm #{timestamp}_gitlab_backup.tar))
+          file_list.map! do |path_string|
+            if path_string =~ /(\d+)(?:_\d{4}_\d{2}_\d{2})?_gitlab_backup\.tar/
+              { timestamp: $1.to_i, path: path_string }
+            end
+          end
+          file_list.sort.each do |file|
+            if Time.at(file[:timestamp]) < (Time.now - keep_time)
+              if Kernel.system(*%W(rm #{file[:path]}))
                 removed += 1
               end
             end
@@ -103,7 +107,7 @@ module Backup
       Dir.chdir(Gitlab.config.backup.path)
 
       # check for existing backups in the backup dir
-      file_list = Dir.glob("*_gitlab_backup.tar").each.map { |f| f.split(/_/).first.to_i }
+      file_list = Dir.glob("*_gitlab_backup.tar")
       puts "no backups found" if file_list.count == 0
 
       if file_list.count > 1 && ENV["BACKUP"].nil?
@@ -112,7 +116,7 @@ module Backup
         exit 1
       end
 
-      tar_file = ENV["BACKUP"].nil? ? File.join("#{file_list.first}_gitlab_backup.tar") : File.join(ENV["BACKUP"] + "_gitlab_backup.tar")
+      tar_file = ENV["BACKUP"].nil? ? file_list.first : file_list.grep(ENV['BACKUP']).first
 
       unless File.exist?(tar_file)
         puts "The specified backup doesn't exist!"