use backup and whenever with capistrano to backup database on vps

gistfile1.rb

1. install bakcup and whenever gem
```
gem 'backup'
gem 'whenever'
```

2. capistrano task(for uploading config file, put it to lib/capistrano/tasks/backup.rake)
```
namespace :backup do

  desc "Upload backup config files."
  task :upload_config do
    on roles(:app) do
      execute "mkdir -p #{fetch(:backup_path)}/models"
      upload! StringIO.new(File.read("config/deploy/backup/config.rb")), "#{fetch(:backup_path)}/config.rb"
      upload! StringIO.new(File.read("config/deploy/backup/models/db_backup.rb")), "#{fetch(:backup_path)}/models/db_backup.rb"
    end
  end

  desc "Upload whenever cron schedule file."
  task :upload_cron do
    on roles(:app) do
      execute "mkdir -p #{fetch(:backup_path)}/config"
      execute "touch #{fetch(:backup_path)}/config/cron.log"
      upload! StringIO.new(File.read("config/deploy/backup/schedule.rb")), "#{fetch(:backup_path)}/config/schedule.rb"

      within "#{fetch(:backup_path)}" do
        # capistrano was unable to find the executable for whenever
        # without the path to rbenv shims set
        with path: "/home/#{fetch(:deploy_user)}/.rbenv/shims:$PATH" do
          puts capture :whenever
          puts capture :whenever, '--update-crontab'
        end
      end
    end
  end

end

```

3. generate config file
```
bakcup -h
backup generate:model -t, --trigger=TRIGGER
backup help backup generate:model

eg. 

backup generate:model --trigger noah_seiko --databases postgresql --archives --storages=local --compressors='gzip'
backup perform -t noah_seiko

cd ~/Backup
mkdir config
wheneverize .

copy files generatedin ~/backup to your projects's folder config/deploy/backup, use cap task to upload it to server, test on server, then use whenever generate a cronjob file .........
```

links:
https://ruby-china.org/topics/4710
http://vladigleba.com/blog/2014/06/30/backup-a-rails-database-with-the-backup-and-whenever-gems/
http://meskyanichi.github.io/backup/v4/getting-started/
noah_seiko project on bitbucket.org