Deploying a Git subdirectory in Capistrano

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.

We're also doing this with Capistrano by cloning down the full repository, deleting the unused files and folders and move the desired folder up the hierarchy.

deploy.rb

set :repository,  "[email protected]:name/project.git"
set :branch, "master"
set :subdir, "server"

after "deploy:update_code", "deploy:checkout_subdir"

namespace :deploy do

    desc "Checkout subdirectory and delete all the other stuff"
    task :checkout_subdir do
        run "mv #{current_release}/#{subdir}/ /tmp && rm -rf #{current_release}/* && mv /tmp/#{subdir}/* #{current_release}"
    end

end

As long as the project doesn't get too big this works pretty good for us, but if you can, create an own repository for each component and group them together with git submodules.

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)

You can have two git repositories (client and server) and add them to a "super-project" (app). In this "super-project" you can add the two repositories as submodules (check this tutorial).

Another possible solution (a bit more dirty) is to have separate branches for client and server, and then you can pull from the 'server' branch.