Deploying Rails Applications to Heroku

22 Jan 2025 | category: rails | Comments
#ruby #heroku #rails #devops

Deploying Rails Applications to Heroku

A Practical Guide for Students

1. Introduction

  • What is Heroku?
    • Cloud platform as a service (PaaS)
    • Perfect for student projects and startups
    • Free tier available for learning and small applications

2. Prerequisites

  • Git installed and configured
  • Ruby and Rails installed locally
  • Basic understanding of command line operations
  • Heroku CLI installed
  • A Rails application ready to deploy

3. Setting Up Your Rails Application

Database Configuration

  • Switch from SQLite to PostgreSQL
  • Update your Gemfile
  • Configure database.yml
  • Set up environment variables

Version Control

  • Initialize Git repository
  • Create .gitignore file
  • Make initial commit

4. Heroku Setup Steps

  1. Create Heroku Account
    • Visit heroku.com
    • Sign up with student email
    • Verify account
  2. Install Heroku CLI 
    # For macOS
brew install heroku/brew/heroku

# For Windows
# Download installer from Heroku website
  3. Login to Heroku 
    heroku login

5. Deployment Process

  1. Create Heroku Application 
    heroku create your-app-name
  2. Configure Environment 
    heroku config:set RAILS_ENV=production
heroku config:set RAILS_MASTER_KEY=<your-master-key>
  3. Deploy Application 
    git push heroku main
  4. Database Setup 
    heroku run rails db:migrate

6. Common Issues and Solutions

  • Asset compilation failures
  • Database migration errors
  • Environment variable misconfigurations
  • Ruby version mismatches

7. Best Practices

  • Always test locally before deploying
  • Use environment variables for sensitive data
  • Keep your master key secure
  • Regular backups of production database
  • Monitor application logs

8. Monitoring and Maintenance

  • Viewing logs: heroku logs --tail
  • Checking app status: heroku ps
  • Scaling your application
  • Database management

9. Additional Resources

  • Heroku Dev Center documentation
  • Rails Guides on deployment
  • Community forums and support
  • Video tutorials and workshops

10. Demo Time!

Let’s walk through a live deployment…

# Create a new Rails application
rails new heroku-demo --database=postgresql

# Navigate to the application directory
cd heroku-demo

# Update Gemfile
# Add these lines to your Gemfile
source 'https://rubygems.org'
git_source(:github) { |repo| "https://github.com/#{repo}.git" }

ruby '3.2.2'

gem 'rails', '~> 7.1.0'
gem 'pg'
gem 'puma'
gem 'bootsnap'
gem 'tzinfo-data'

group :development, :test do
  gem 'debug'
end

group :development do
  gem 'web-console'
end

# Create a simple welcome controller
rails generate controller Welcome index

# Add route to config/routes.rb
Rails.application.routes.draw do
  root 'welcome#index'
end

# Create app/views/welcome/index.html.erb
# Add this content:
<h1>Welcome to Our Demo App!</h1>
<p>This application is deployed on Heroku</p>
<p>Server time: <%= Time.current %></p>

# Database configuration (config/database.yml)
default: &default
  adapter: postgresql
  encoding: unicode
  pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>

development:
  <<: *default
  database: heroku_demo_development

test:
  <<: *default
  database: heroku_demo_test

production:
  <<: *default
  url: <%= ENV['DATABASE_URL'] %>

# Initialize Git repository
git init
git add .
git commit -m "Initial commit"

# Create Heroku app and deploy
heroku create heroku-demo-app
git push heroku main
heroku run rails db:migrate