DZone Snippets: capistrano code

Upgrade rubygems and/or specific gems themselves via capistrano

nicwilliams (Dr Nic Williams) — Wed, 19 Dec 2007 22:10:32 GMT

When a latest RubyGems is released (e.g. 0.9.5 recently) or Rails (e.g. 2.0.2) you might want to push those upgrades to all your production machines.

Add these two tasks to your deploy.rb capistrano file (add namespaces for cap2.0 if you like)



  desc "Updates RubyGems version"

  task :gem_update_system do

    sudo "gem update --system"

  end



    

  desc "Install a RubyGem from remote source"

  task :gem_install do

    puts "USAGE: GEM=gemname cap gems_install" and next unless ENV['GEM']

    sudo "gem install #{ENV['GEM']} --no-ri --no-rdoc"

  end

To upgrade rubygems and rails, for example:



cap gem_update_system

GEM=rails cap gem_install

Dump postgres production data into development database

nicwilliams (Dr Nic Williams) — Sun, 06 May 2007 09:00:17 GMT

When bug requests come in, its great to grab a copy of the current production (or system test env) data and sync it into your development database.

Here's a capistrano recipe for postgresql:



desc "Dumps target database into development db"

task :sync_db do

  env   = ENV['RAILS_ENV'] || ENV['DB'] || 'production'

  file  = "#{application}.sql.bz2"

  remote_file = "#{shared}/log/#{file}"

  run "pg_dump --clean --no-owner --no-privileges -U#{db_user} -h#{db_host} #{db_name}_#{env} | bzip2 > #{file}" do |ch, stream, out|

    ch.send_data "#{db_password}\n" if out =~ /^Password:/

    puts out

  end

  puts rsync = "rsync #{user}@#{domain}:#{file} tmp"

  `#{rsync}`

  puts depackage = "bzcat tmp/#{file} | psql #{local_db_dev}"

  `#{depackage}`

end

Capistrano logs

nicwilliams (Dr Nic Williams) — Tue, 10 Apr 2007 20:09:05 GMT

To get the last n lines from a remote log file, use this task

Usage: cap log [-s lines=100] [-s rails_env=production]
So, "cap log" returns 100 lines from production.



desc "Returns last lines of log file. Usage: cap log [-s lines=100] [-s rails_env=production]"

task :log do

  lines     = configuration.variables[:lines] || 100

  rails_env = configuration.variables[:rails_env] || 'production'

  run "tail -n #{lines} #{app_dir}/log/#{rails_env}.log" do |ch, stream, out|

    puts out

  end

end