> ## Documentation Index
> Fetch the complete documentation index at: https://mintlify.com/dotandev/envcheck/llms.txt
> Use this file to discover all available pages before exploring further.

# Rails Project

> Environment validation for Ruby on Rails applications

## Overview

This example demonstrates envcheck configuration for a Ruby on Rails application. It validates Ruby and Bundler versions, optional Node.js and Yarn for asset compilation, environment variables with pattern matching, and Rails-specific files.

## Configuration

```yaml .envcheck.yaml theme={null}
version: "1"

tools:
  - name: ruby
    version: ">=3.0.0"
    required: true
  - name: bundle
    required: true
  - name: node
    required: false
  - name: yarn
    required: false

env_vars:
  - name: DATABASE_URL
    required: true
  - name: RAILS_ENV
    required: false
    pattern: "^(development|test|production)$"

ports:
  - 3000

files:
  - path: Gemfile
    required: true
  - path: config/database.yml
    required: true
  - path: .env
    required: false
```

## What This Checks

### Tools

* **ruby >=3.0.0**: Ensures compatibility with Rails 7.x and modern Ruby features
* **bundle**: Validates Bundler is available for gem dependency management
* **node** (optional): Required for Rails asset pipeline and JavaScript compilation
* **yarn** (optional): Modern JavaScript package manager for Rails with Webpacker/jsbundling

### Environment Variables

* **DATABASE\_URL** (required): Database connection string - critical for Active Record
* **RAILS\_ENV** (optional): When set, validates it's a valid Rails environment (development/test/production)

### Ports

* **3000**: Rails default development server port for `rails server`

### Files

* **Gemfile**: Ruby dependencies manifest - required for all Rails projects
* **config/database.yml**: Database configuration - Rails standard location
* **.env** (optional): Environment variables file - recommended but not required

## Expected Output

<CodeGroup>
  ```bash Success theme={null}
  $ envcheck

  ✓ Tools
    ✓ ruby: 3.2.2 (>= 3.0.0)
    ✓ bundle: installed
    ✓ node: installed
    ✓ yarn: installed

  ✓ Environment Variables
    ✓ DATABASE_URL: ***
    ✓ RAILS_ENV: development

  ✓ Ports
    ✓ 3000: available

  ✓ Files
    ✓ Gemfile: exists
    ✓ config/database.yml: exists
    ✓ .env: exists

  All checks passed!
  ```

  ```bash Validation Error theme={null}
  $ envcheck

  ✗ Tools
    ✗ ruby: 2.7.5 (expected >= 3.0.0)
    ✓ bundle: installed
    ✓ node: not found (optional)
    ✓ yarn: not found (optional)

  ✗ Environment Variables
    ✗ DATABASE_URL: not set
    ✗ RAILS_ENV: "staging" (does not match pattern)

  ✗ Ports
    ✗ 3000: in use

  ✓ Files
    ✓ Gemfile: exists
    ✓ config/database.yml: exists

  Checks failed!
  ```
</CodeGroup>

## Tips for Rails Projects

<Tip>
  Use `dotenv-rails` gem to automatically load `.env` files in development and test environments. Add `.env` to `.gitignore` and commit `.env.example` as a template.
</Tip>

<Warning>
  The pattern validation ensures RAILS\_ENV only accepts standard environments. If you use custom environments like "staging", update the pattern to include them.
</Warning>

<Info>
  Node.js and Yarn are marked optional because not all Rails apps need JavaScript bundling. Rails 7+ can work with import maps, eliminating the Node.js dependency.
</Info>

## Common Variations

### Rails API-Only Mode

Simplified checks for API applications:

```yaml theme={null}
tools:
  - name: ruby
    version: ">=3.0.0"
    required: true
  - name: bundle
    required: true

env_vars:
  - name: DATABASE_URL
    required: true
  - name: SECRET_KEY_BASE
    required: true
  - name: RAILS_ENV
    required: false
    pattern: "^(development|test|production)$"

ports:
  - 3000

files:
  - path: Gemfile
    required: true
  - path: config/database.yml
    required: true
```

### Rails with Hotwire/Turbo

Modern Rails with minimal JavaScript:

```yaml theme={null}
tools:
  - name: ruby
    version: ">=3.0.0"
    required: true
  - name: bundle
    required: true
  - name: node
    required: false  # Optional with import maps

files:
  - path: Gemfile
    required: true
  - path: config/importmap.rb
    required: false
  - path: app/views/layouts/application.html.erb
    required: true
```

### Rails with Webpacker/esbuild

Full JavaScript toolchain:

```yaml theme={null}
tools:
  - name: ruby
    version: ">=3.0.0"
    required: true
  - name: bundle
    required: true
  - name: node
    version: ">=16.0.0"
    required: true
  - name: yarn
    required: true

files:
  - path: Gemfile
    required: true
  - path: package.json
    required: true
  - path: yarn.lock
    required: true
```

### Rails with Sidekiq

Background job processing:

```yaml theme={null}
tools:
  - name: ruby
    version: ">=3.0.0"
    required: true
  - name: bundle
    required: true
  - name: redis-cli
    required: true

env_vars:
  - name: DATABASE_URL
    required: true
  - name: REDIS_URL
    required: true

ports:
  - 3000  # Rails
  - 6379  # Redis
```

### Rails Production Deployment

Production environment validation:

```yaml theme={null}
tools:
  - name: ruby
    version: ">=3.0.0"
    required: true
  - name: bundle
    required: true

env_vars:
  - name: DATABASE_URL
    required: true
  - name: SECRET_KEY_BASE
    required: true
  - name: RAILS_ENV
    required: true
    pattern: "^production$"
  - name: RAILS_SERVE_STATIC_FILES
    required: false
  - name: RAILS_LOG_TO_STDOUT
    required: false

files:
  - path: Gemfile.lock
    required: true
  - path: public/assets/.sprockets-manifest-*.json
    required: false
```

### Multi-Database Rails App

Rails 6+ with multiple databases:

```yaml theme={null}
env_vars:
  - name: DATABASE_URL
    required: true
  - name: ANALYTICS_DATABASE_URL
    required: true
  - name: CACHE_DATABASE_URL
    required: false

files:
  - path: config/database.yml
    required: true
  - path: db/primary_schema.rb
    required: false
  - path: db/analytics_schema.rb
    required: false
```

## Rails-Specific Considerations

### Database URL Format

Common DATABASE\_URL patterns for Rails:

* PostgreSQL: `postgresql://user:password@localhost/mydb`
* MySQL: `mysql2://user:password@localhost/mydb`
* SQLite: `sqlite3:db/development.sqlite3`

### Ruby Version Managers

Popular tools for managing Ruby versions:

* **rbenv**: Lightweight Ruby version management
* **rvm**: Ruby Version Manager with gemsets
* **asdf**: Multi-runtime version manager

Consider adding `.ruby-version` file:

```yaml theme={null}
files:
  - path: .ruby-version
    required: true
```

### Credentials and Security

Rails 5.2+ uses encrypted credentials:

```yaml theme={null}
env_vars:
  - name: RAILS_MASTER_KEY
    required: true  # For production

files:
  - path: config/credentials.yml.enc
    required: true
  - path: config/master.key
    required: false  # Should be in .gitignore
```

### Asset Compilation

For apps with compiled assets, ensure NODE\_ENV:

```yaml theme={null}
env_vars:
  - name: NODE_ENV
    required: false
    pattern: "^(development|production)$"
```

## Learn More

* [Tools Validator](/configuration/tools) - Ruby version management and bundler
* [Environment Variables](/configuration/environment-variables) - Pattern validation for Rails environments
* [Port Checker](/configuration/ports) - Rails server and service ports
* [File Validator](/configuration/files) - Rails directory structure validation