Directory Structure
Let’s take a quick glance at the files and directories that are included in a new Rails application.
Go to the terminal (to your right) and run the following command:
$ ls -laHere is what you should see in the output:
| File/Folder | Purpose |
|---|---|
| app/ | Contains the controllers, models, views, helpers, mailers, jobs, and assets for your application. You’ll focus mostly on this folder for the remainder of this guide. |
| bin/ | Contains the rails script that starts your app and can contain other scripts you use to set up, update, deploy, or run your application. |
| config/ | Contains configuration for your application’s routes, database, and more. This is covered in more detail in Configuring Rails Applications. |
| config.ru | Rack configuration for Rack-based servers used to start the application. |
| db/ | Contains your current database schema, as well as the database migrations. |
| Dockerfile† | Configuration file for Docker. |
| Gemfile | These files allow you to specify what gem dependencies are needed for your Rails application. These files are used by the Bundler gem. |
| Gemfile.lock† | The lock file that ensures consistent gem versions across different environments. |
| lib/ | Extended modules for your application. |
| log/ | Application log files. |
| public/ | Contains static files and compiled assets. When your app is running, this directory will be exposed as-is. |
| Rakefile | This file locates and loads tasks that can be run from the command line. The task definitions are defined throughout the components of Rails. Rather than changing Rakefile, you should add your own tasks by adding files to the lib/tasks directory of your application. |
| README.md | This is a brief instruction manual for your application. You should edit this file to tell others what your application does, how to set it up, and so on. |
| script/ | Contains one-off or general purpose scripts and benchmarks. |
| storage/ | Contains SQLite databases and Active Storage files for Disk Service. This is covered in Active Storage Overview. |
| test/ | Unit tests, fixtures, and other test apparatus. These are covered in Testing Rails Applications. |
| tmp/ | Temporary files (like cache and pid files). |
| vendor/ | A place for all third-party code. In a typical Rails application this includes vendored gems. |
| .dockerignore† | This file tells Docker which files it should not copy into the container. |
| .gitattributes† | This file defines metadata for specific paths in a Git repository. This metadata can be used by Git and other tools to enhance their behavior. See the gitattributes documentation for more information. |
| .git/† | Contains Git repository files. |
| .github/† | Contains GitHub specific files. |
| .gitignore† | This file tells Git which files (or patterns) it should ignore. See GitHub - Ignoring files for more information about ignoring files. |
| .kamal/† | Contains Kamal secrets and deployment hooks. |
| .rubocop.yml† | This file contains the configuration for RuboCop. |
| .ruby-version | This file contains the default Ruby version. |
Files
Preparing Environment
- Preparing Ruby runtime