deploy.rb

# Clear existing task so we can replace it rather than "add" to it.
Rake::Task["deploy:compile_assets"].clear 

desc "Precompile assets locally and then rsync to web servers" 
task :compile_assets do 
  # compile assets locally
  run_locally do
    with rails_env: fetch(:stage) do
      execute :bundle, "exec rake assets:precompile"
    end
  end

  # rsync to each server
  local_dir = "./public/assets/"
  on roles(:web) do
    # this needs to be done outside run_locally in order for host to exist
    remote_dir = "#{host.user}@#{host.hostname}:#{shared_path}/public/assets/"
    
    run_locally { execute "rsync -av --delete #{local_dir} #{remote_dir}" }
  end

  # clean up
  run_locally { execute "rm -rf #{local_dir}" }
end

👍

My ssh port is not the default port 22.

How can I tweak this so I can specify a port in my connection?

remote_dir = "#{host.user}@#{host.hostname}:#{shared_path}/public/assets/"    
run_locally { execute "rsync -av --delete #{local_dir} #{remote_dir}" }

I figured it out, you need to change

run_locally { execute "rsync -av --delete #{local_dir} #{remote_dir}" }

to this:

run_locally { execute "rsync -av -e 'ssh -p 2222' --delete #{local_dir} #{remote_dir}" }

Thanks !

made another version, includes some changes to fully integrate in capistrano flow (and make rollback work)