deploy.rb

set :git_reuse_repo, true

class Vlad::Git
  def checkout(revision, destination)
    destination = File.join(destination, 'repo')
    revision = 'HEAD' if revision =~ /head/i
 
    cached_upate = [
      "cd #{destination}",
      "#{git_cmd} fetch origin",
      "#{git_cmd} reset --hard origin/#{revision}"
    ].join " && "
 
    clone = [
      "#{git_cmd} clone #{repository} #{destination}",
      "cd #{destination}",
      "#{git_cmd} checkout -f -b deployed-#{revision} #{revision}"
    ].join " && "
 
    update = if defined?(git_reuse_repo) && git_reuse_repo
      "if [ -e #{destination} ]; then #{cached_upate}; else #{clone}; fi"
    else
      "rm -rf #{destination} && #{clone}"
    end

    "sh -c \"#{update}\""
  end
end

result

20:41 gva@dell:~/work/bookfeed autocomments >rake vlad:deploy --trace
(in /home/gva/work/bookfeed)
./config/deploy.rb:18: warning: method redefined; discarding old checkout
** Invoke vlad:deploy (first_time)
** Invoke vlad:update (first_time)
** Execute vlad:update
ssh bfeed.ru 'cd /home/gva/bookfeed_alpha/scm && sh -c "if [ -e /home/gva/bookfeed_alpha/scm/repo ]; then cd /home/gva/bookfeed_alpha/scm/repo && git fetch origin && git reset --hard origin/HEAD; else git clone git@github.com:gumayunov/bookfeed.git /home/gva/bookfeed_alpha/scm/repo && cd /home/gva/bookfeed_alpha/scm/repo && git checkout -f -b deployed-HEAD HEAD; fi" && mkdir -p /home/gva/bookfeed_alpha/releases/20090722211501 && cd repo && git archive --format=tar deployed-HEAD | (cd /home/gva/bookfeed_alpha/releases/20090722211501 && tar xf -) && cd - && cd .. && chmod -R g+w /home/gva/bookfeed_alpha/releases/20090722211501 && rm -rf /home/gva/bookfeed_alpha/releases/20090722211501/log /home/gva/bookfeed_alpha/releases/20090722211501/public/system /home/gva/bookfeed_alpha/releases/20090722211501/tmp/pids && mkdir -p /home/gva/bookfeed_alpha/releases/20090722211501/db /home/gva/bookfeed_alpha/releases/20090722211501/tmp'