a capistrano strategy to deploy sub-directory in repository with "copy" strategy

copy_subdir.rb

#!/usr/bin/env ruby
#
# a capistrano strategy to deploy sub-directory in the repository.
# this is a stuff like "remote_cache_subdir" strategy described in following page,
# but based on "copy" strategy of capistrano deploy recipe.
#
# http://stackoverflow.com/questions/29168/deploying-a-git-subdirectory-in-capistrano
#

require 'capistrano'
require 'capistrano/recipes/deploy/strategy/copy'
require 'tmpdir'

class CopySubdir < Capistrano::Deploy::Strategy::Copy

  def deploy!
    update_repository_cache
    copy_repository_cache
    distribute!
  ensure
    FileUtils.rm filename rescue nil
    FileUtils.rm_rf destination rescue nil
    FileUtils.rm_rf repository_cache rescue nil if remove_repository_cache?
  end

  private

  def update_repository_cache
    if File.exists?(repository_cache)
      logger.debug "refreshing local cache to revision #{revision} at #{repository_cache}"
      system(source.sync(revision, repository_cache))
    else
      logger.debug "preparing local cache at #{repository_cache}"
      system(source.checkout(revision, repository_cache))
    end

    # Check the return code of last system command and rollback if not 0
    unless $? == 0
      raise Capistrano::Error, "shell command failed with return code #{$?}"
    end
  end

  def copy_repository_cache
    logger.debug "copying cache from #{repository_cache_subdir} to deployment staging area #{destination}"
    if copy_exclude.empty?
      run_locally "cp -RPp #{repository_cache_subdir} #{destination} && #{mark}"
    else
      exclusions = copy_exclude.map { |e| "--exclude=\"#{e}\"" }.join(' ')
      run_locally "rsync -lrpt #{exclusions} #{repository_cache_subdir}/ #{destination} && #{mark}"
    end

    logger.trace "compressing #{destination} to #{filename}"
    Dir.chdir(copy_dir) { system(compress(File.basename(destination), File.basename(filename)).join(" ")) }
  end

  # Returns the command which will write the identifier of the
  # revision being deployed to the REVISION file on each host.
  def mark
    "(echo #{revision} > #{destination}/REVISION)"
  end

  # Remote filename should be differ from local filename to allow deploy to localhost.
  def remote_filename
    @remote_filename ||= File.join(remote_dir, "copy-#{File.basename(destination)}.#{compression.extension}")
  end

  # Local repository path.
  def repository_cache
    @repository_cache ||= copy_cache || Dir.mktmpdir('cached-copy', copy_dir) { |dir| dir }
  end

  # Deploy subtree specified as :deploy_subdir in local repository.
  def repository_cache_subdir
    @repository_cache_subdir ||= if configuration[:deploy_subdir] then
                                   File.join(repository_cache, configuration[:deploy_subdir])
                                 else
                                   repository_cache
                                 end
  end

  # Remove local repository cache if :copy_cache is not enabled.
  def remove_repository_cache?
    !copy_cache
  end
end

set :strategy, CopySubdir.new(self)

# vim:set ft=ruby :