Deploying a Git subdirectory in Capistrano

My master branch layout is like this:

/ <-- top level

/client <-- desktop client source files

/server <-- Rails app

What I'd like to do is only pull down the /server directory in my deploy.rb, but I can't seem to find any way to do that. The /client directory is huge, so setting up a hook to copy /server to / won't work very well, it needs to only pull down the Rails app.

Solution 1:

Without any dirty forking action but even dirtier !

In my config/deploy.rb :

set :deploy_subdir, "project/subdir"

Then I added this new strategy to my Capfile :

require 'capistrano/recipes/deploy/strategy/remote_cache'

class RemoteCacheSubdir < Capistrano::Deploy::Strategy::RemoteCache

  private

  def repository_cache_subdir
    if configuration[:deploy_subdir] then
      File.join(repository_cache, configuration[:deploy_subdir])
    else
      repository_cache
    end
  end

  def copy_repository_cache
    logger.trace "copying the cached version to #{configuration[:release_path]}"
    if copy_exclude.empty? 
      run "cp -RPp #{repository_cache_subdir} #{configuration[:release_path]} && #{mark}"
    else
      exclusions = copy_exclude.map { |e| "--exclude=\"#{e}\"" }.join(' ')
      run "rsync -lrpt #{exclusions} #{repository_cache_subdir}/* #{configuration[:release_path]} && #{mark}"
    end
  end

end


set :strategy, RemoteCacheSubdir.new(self)

Solution 2:

For Capistrano 3.0, I use the following:

In my Capfile:

# Define a new SCM strategy, so we can deploy only a subdirectory of our repo.
module RemoteCacheWithProjectRootStrategy
  def test
    test! " [ -f #{repo_path}/HEAD ] "
  end

  def check
    test! :git, :'ls-remote', repo_url
  end

  def clone
    git :clone, '--mirror', repo_url, repo_path
  end

  def update
    git :remote, :update
  end

  def release
    git :archive, fetch(:branch), fetch(:project_root), '| tar -x -C', release_path, "--strip=#{fetch(:project_root).count('/')+1}"
  end
end

And in my deploy.rb:

# Set up a strategy to deploy only a project directory (not the whole repo)
set :git_strategy, RemoteCacheWithProjectRootStrategy
set :project_root, 'relative/path/from/your/repo'

All the important code is in the strategy release method, which uses git archive to archive only a subdirectory of the repo, then uses the --strip argument to tar to extract the archive at the right level.

UPDATE

As of Capistrano 3.3.3, you can now use the :repo_tree configuration variable, which makes this answer obsolete. For example:

set :repo_url, 'https://example.com/your_repo.git'
set :repo_tree, 'relative/path/from/your/repo' # relative path to project root in repo

See http://capistranorb.com/documentation/getting-started/configuration.