Deploying Rails Applications | Advanced Rails

Introduction

Deploying a Rails application involves moving your application from the development environment to a production environment where it can be accessed by users. This guide will cover the steps and best practices for deploying Rails applications.

Key Points:

Choose a deployment method and hosting provider.
Prepare your application for deployment.
Automate the deployment process for efficiency and reliability.

Choosing a Deployment Method

There are several methods to deploy a Rails application. Some popular methods include:

Heroku: A platform-as-a-service (PaaS) that simplifies deployment.
Capistrano: A remote server automation and deployment tool.
Docker: Containerize your application for consistency and scalability.

Deploying to Heroku

Heroku is a popular choice for deploying Rails applications due to its simplicity and ease of use. Here is how to deploy a Rails application to Heroku:

# Install the Heroku CLI
brew tap heroku/brew && brew install heroku

# Log in to Heroku
heroku login

# Create a new Heroku app
heroku create my-rails-app

# Add the Heroku Git remote
git remote add heroku https://git.heroku.com/my-rails-app.git

# Push your code to Heroku
git push heroku main

# Run database migrations on Heroku
heroku run rails db:migrate

# Open your application in the browser
heroku open

Deploying with Capistrano

Capistrano is a remote server automation and deployment tool that can be used to deploy Rails applications to virtual private servers (VPS) or cloud providers like AWS. Here is how to deploy with Capistrano:

# Add Capistrano to your Gemfile
gem 'capistrano', require: false
gem 'capistrano-rails', require: false
gem 'capistrano-passenger', require: false

# Install the gems
bundle install

# Initialize Capistrano
bundle exec cap install

# Update Capfile to include Rails and Passenger
# Capfile
require 'capistrano/rails'
require 'capistrano/passenger'

# Configure deployment settings
# config/deploy.rb
lock '3.14.1'

set :application, 'my_app_name'
set :repo_url, 'git@github.com:me/my_repo.git'

set :deploy_to, '/var/www/my_app_name'

append :linked_files, 'config/database.yml', 'config/master.key'
append :linked_dirs, 'log', 'tmp/pids', 'tmp/cache', 'tmp/sockets', 'public/system'

# Configure server settings
# config/deploy/production.rb
server 'example.com', user: 'deploy', roles: %w{app db web}

# Deploy your application
bundle exec cap production deploy

Deploying with Docker

Docker allows you to containerize your application, ensuring consistency across different environments. Here is how to deploy a Rails application with Docker:

# Create a Dockerfile
# Dockerfile
FROM ruby:2.7
RUN apt-get update -qq && apt-get install -y nodejs postgresql-client
WORKDIR /myapp
COPY Gemfile /myapp/Gemfile
COPY Gemfile.lock /myapp/Gemfile.lock
RUN bundle install
COPY . /myapp

# Create a Docker Compose file
# docker-compose.yml
version: '3'
services:
  db:
    image: postgres
  web:
    build: .
    command: bash -c "rm -f tmp/pids/server.pid && bundle exec rails s -b '0.0.0.0'"
    volumes:
      - ".:/myapp"
    ports:
      - "3000:3000"
    depends_on:
      - db

# Build and run the containers
docker-compose up --build

# Run database migrations
docker-compose run web rails db:migrate

Preparing Your Application

Before deploying your Rails application, ensure that it is ready for production:

Environment variables: Use environment variables for configuration, such as database credentials and API keys.
Database setup: Ensure your database is properly configured and migrations are up to date.
Asset precompilation: Precompile your assets for faster load times.
Logging: Set up proper logging to monitor your application's performance and errors.

# Precompile assets
rails assets:precompile RAILS_ENV=production

# Run database migrations
rails db:migrate RAILS_ENV=production

Automating Deployment

Automating the deployment process can save time and reduce errors. Here are some tools and strategies for automating deployment:

CI/CD pipelines: Use continuous integration and continuous deployment pipelines with tools like GitHub Actions, GitLab CI, or CircleCI.
Deployment scripts: Write custom deployment scripts to automate repetitive tasks.

# Example GitHub Actions workflow
# .github/workflows/deploy.yml
name: Deploy

on:
  push:
    branches:
      - main

jobs:
  deploy:
    runs-on: ubuntu-latest

    steps:
      - name: Checkout code
        uses: actions/checkout@v2

      - name: Set up Ruby
        uses: ruby/setup-ruby@v1
        with:
          ruby-version: 2.7

      - name: Install dependencies
        run: bundle install --jobs 4 --retry 3

      - name: Deploy to Heroku
        env:
          HEROKU_API_KEY: ${{ secrets.HEROKU_API_KEY }}
        run: |
          git remote add heroku https://git.heroku.com/my-rails-app.git
          git push heroku main

Conclusion

Deploying Rails applications involves several steps, from choosing a deployment method to preparing your application and automating the process. By following the best practices and using the right tools, you can ensure a smooth and efficient deployment process for your Rails applications.

Ruby on Rails - Deploying Rails Applications