Installation

Lesli is a modular Ruby on Rails framework distributed as a gem. It integrates into your application while keeping its code, database migrations, and assets isolated from your main app. This design allows you to extend your system with new capabilities without increasing complexity or risking conflicts in your core codebase.

Requirements:
- Ruby 3.2.x
- Rails 8.0.x
- Node.js 20.x (required for LesliAssets)

1. Create a New Rails Application

Start by generating a fresh Rails application that will host Lesli.

rails new LesliApp
cd LesliApp

2. Install the Lesli Core

Add the Lesli gem to your project:

bundle add lesli

If you plan to contribute or develop Lesli locally, you can instead clone the repository. See the development guide for details.

Verify the installation:

rake lesli:status

This command prints the current status of the Lesli framework and confirms that it is correctly loaded in your application.

3. Run the Installation Generator

Initialize Lesli in your Rails application:

rails generate lesli:install

This generator will:

• Create the Lesli configuration file: config/initializers/lesli.rb

• Mount the Lesli routing layer inside config/routes.rb:

Rails.application.routes.draw do
  Lesli::Router.mount(self)
end

The initializer allows you to configure global Lesli behavior and framework options.

4. Prepare the Database

Lesli provides a task that prepares a complete development environment.

rake lesli:db:dev

This task will:

• Run all database migrations
• Build privileges (if LesliSecurity is installed)
• Import translations (if LesliBabel is installed)
• Seed demo users and sample data for installed engines
• Output a summary of the current system status

5. Reset the Database (Optional)

If you need to reset your environment during development:

rake lesli:db:reset

This command drops, recreates, migrates, and reseeds the database using the same logic as lesli:db:dev.

6. Start the Rails Server

Run the development server:

rails s

Additional examples:

rails s --binding=0.0.0.0
rails s --environment=test
rails s --environment=development
RAILS_SERVE_STATIC_FILES=true rails s --environment=production

Open your browser and visit:

http://127.0.0.1:3000/login

You should now see the Lesli welcome page.

Development Recommendations

Local Email Preview

For development environments it is recommended to preview emails locally instead of sending them.

Install the letter_opener gem:

group :development do
  gem "letter_opener"
end

Configure config/environments/development.rb:

config.action_mailer.delivery_method = :letter_opener
config.action_mailer.perform_deliveries = true
config.action_mailer.default_url_options = { host: "localhost", port: 3000 }

Emails generated by your application will automatically open in your browser.