创建Capistrano任务,根据角色执行不同的任务

role :app, %w{deploy@example.com}

task :restart_app do
  on roles(:app) do
    execute "touch #{fetch(:deploy_to)}/tmp/restart.txt"
  end
end

role :app, %w{deploy@example.com}
role :db, %w{db_admin@example.com}

task :migrate_db do
  on roles(:db) do
    within release_path do
      with rails_env: fetch(:rails_env) do
        execute :rake, "db:migrate"
      end
    end
  end
end