Ahoy, mateys! Welcome aboard the grand adventure that be “Linux for Pirates! Ruby on Whales” This here tome be yer trusty map through the treacherous seas of Ruby on Rails, Docker, and the mystical arts of DevOps. Whether ye be a scallywag just learning the ropes or a seasoned buccaneer, this book be the compass to guide ye through the stormy waters of modern application deployment.
“Rails and DevOps with Docker for Pirates!” be perfect for:
Before ye embark on this grand adventure, make sure ye have the following knowledge and tools at yer disposal:
By having these prerequisites, ye’ll be well-prepared to navigate the treacherous seas of modern application deployment with “Rails and DevOps with Docker for Pirates!” Ready yerself, and let the adventure begin!
In this fast-paced world of tech, mastering the integration of development and operations be crucial. Docker be revolutionizin’ application deployment, makin’ it easier to build, ship, and run applications consistently across different environments. This book provides a hands-on, practical approach to implementin’ these technologies, ensuring ye can deliver reliable, scalable, and secure applications.
Join the adventure with “Rails and DevOps with Docker for Pirates!” and embark on a journey to become a master of modern web development and deployment. Whether ye be settin’ sail for the first time or seekin’ to enhance yer skills, this book be yer ultimate guide to navigatin’ the digital seas.
Ahoy, me hearties! Gather ‘round and let me spin ye a yarn about Dean Lofts, the legendary Loftwah of the tech and music seas. Dean be a seasoned DevOps Engineer, currently plundering the digital waves at Operoo. With over a decade of swashbuckling experience, Dean has amassed a treasure trove of skills in infrastructure management, network security, and cloud computing, with a particular prowess in AWS. His journey through various industries and roles has forged him into a versatile and formidable force, capable of tackling the most complex technical challenges.
Dean’s voyage began in the Royal Australian Navy, where he served as a Communications and Information Systems Sailor. For six years, he braved the high seas of satellite communication, radio operation, and LAN administration. His valor and skill earned him prestigious medals, such as the Australian Active Service Medal, the Iraq Medal, and the Australian Defence Medal. This military stint laid a strong keel for his technical expertise and disciplined approach to problem-solving.
After his naval adventures, Dean set sail into civilian waters, taking on roles like System Engineer at Unisys and Solutions Consultant at UXC Connect. At UXC Connect, he navigated high-profile projects for clients like Chevron and the Department of Defence, ensuring their systems stayed afloat and their infrastructure was shipshape.
Dean’s prowess grew with roles such as Senior Test & Integration Technician at Thales and System Administrator at PVS Australia Pty Ltd. He maintained IT infrastructure, implemented network security measures, and optimized system performance, honing his skills in troubleshooting, infrastructure management, and cloud computing.
In his recent voyages, including Site Reliability Engineer at PlayHQ Sports and DevOps Engineer at CorpCloud Pty Ltd, Dean bridged the gap between development and IT operations. He wielded automation tools to create scalable and reliable software systems, championing the importance of continuous integration and continuous deployment (CI/CD) practices.
Dean’s technical arsenal be extensive and highly endorsed. Key skills include:
Dean’s skills have been recognized and endorsed by shipmates and landlubbers alike, highlighting his expertise and reliability.
Dean be a passionate advocate for open source, making significant contributions to numerous projects, including Appwrite, EddieHub, BioDrop, NASA, and WordPress. He served as an ambassador for these communities, driving technological advancement and fostering a collaborative environment. His open-source contributions reflect his commitment to sharing knowledge and improving the tech ecosystem.
One of Dean’s notable feats be his integration of the yjit compiler, which delivered a 15% performance boost and substantial cost savings. This innovation showcases his ability to identify and implement improvements that have a meaningful impact on performance and efficiency.
Beyond the tech realm, Dean be an accomplished music producer known as Loftwah The Beatsmiff. He has produced albums and collaborated with artists like Grind Mode Cypher and OptiMystic MC. His musical projects, including “Salty Waterz” and “Day of the Guiding Light,” demonstrate his creative prowess and ability to blend technical precision with artistic expression.
Dean be the author of “Linux for Pirates!”, a unique and engaging book that demystifies Linux for enthusiasts and professionals alike. The book’s innovative approach and accessible style have made it a valuable resource for those looking to deepen their understanding of Linux. Dean’s ability to break down complex concepts into understandable content be evident in his writing and teaching.
In his personal life, Dean be a dedicated father and mental health advocate. He balances his professional and creative pursuits with a commitment to his family and personal well-being. Dean enjoys beat making, reading, and curating tech-focused content on his YouTube channel, where he shares insights and tutorials with a broad audience.
Dean’s journey be a testament to his relentless pursuit of excellence and his commitment to sharing knowledge with the community. His work ethic and innovative approach have earned him accolades and recognition in both the tech and music industries.
To learn more about Dean’s multifaceted journey, check out his contributions on platforms like GitHub, listen to his music on Spotify, and read his insightful tech articles. Welcome to Dean’s world—a blend of rhythm, code, and a relentless drive for excellence.
Ahoy, mateys! Before we hoist the sails and embark on our grand adventure with Ruby on Rails, let’s take a moment to understand the history and significance of this mighty framework.
Ruby on Rails, often simply called Rails, was forged by the brilliant mind of David Heinemeier Hansson (DHH) back in 2004. Rails be a powerful web application framework written in the Ruby programming language, designed to make the development of web applications smoother than a calm sea. It follows the principles of Convention over Configuration (CoC) and Don’t Repeat Yourself (DRY), allowing buccaneers like ye to write less code and achieve more.
Rails has charted the course for many popular web applications, including Basecamp, GitHub, and Shopify. Its treasure lies in its simplicity and productivity, enabling developers to build complex applications swiftly and efficiently.
Now, let’s set sail and create our Rails application. Follow these steps to ensure your ship is well-equipped for the journey ahead.
To begin our voyage, we need to install Ruby. There be several ways to manage Ruby versions on your system. We’ll cover the most popular methods: RVM, rbenv, ruby-install, and chruby. Choose the one that best suits your needs.
Install RVM:
Head over to the RVM website for the latest installation instructions. As of now, you can use this command to install RVM:
curl -sSL https://get.rvm.io | bash -s stable
Load RVM into your shell session:
source ~/.rvm/scripts/rvm
Add RVM to your shell configuration file (e.g., .zshrc):
echo 'source ~/.rvm/scripts/rvm' >> ~/.zshrc
Install Ruby using RVM:
rvm install 3.3.0
rvm use 3.3.0 --default
Verify the installation:
ruby -v
While RVM be a popular choice, there be other ways to manage Ruby versions. Here be a quick overview:
Each of these tools has its own way of configuring your shell (e.g., .zshrc). Here’s what to do:
rbenv:
echo 'export PATH="$HOME/.rbenv/bin:$PATH"' >> ~/.zshrc
echo 'eval "$(rbenv init - zsh)"' >> ~/.zshrc
chruby:
echo 'source /usr/local/share/chruby/chruby.sh' >> ~/.zshrc
echo 'source /usr/local/share/chruby/auto.sh' >> ~/.zshrc
echo 'chruby ruby-3.3.0' >> ~/.zshrc
Once ye’ve configured yer shell, restart it or run source ~/.zshrc
to apply the changes.
To ensure yer shell be properly set up, ye can check if the Ruby version manager is working correctly:
Open a new terminal session or run:
source ~/.zshrc
Verify the Ruby version:
ruby -v
This should return ruby 3.3.0
if everything be set up correctly.
With Ruby ready to set sail, it’s time to install Rails.
Install Rails:
gem install rails
Verify the installation:
rails -v
Now, it’s time to create our Rails application. We’ll set it up to use PostgreSQL as the database and Tailwind CSS for styling.
Create a new Rails application with PostgreSQL and Tailwind CSS:
rails new pirate_app -d postgresql --css tailwind
cd pirate_app
Configure PostgreSQL: Open the config/database.yml
file and configure it for PostgreSQL:
default: &default
adapter: postgresql
encoding: unicode
pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
username: postgres
password: postgres
host: localhost
development:
<<: *default
database: pirate_app_development
test:
<<: *default
database: pirate_app_test
production:
<<: *default
database: pirate_app_production
username: pirate_app
password: <%= ENV['PIRATE_APP_DATABASE_PASSWORD'] %>
Note: your configuration for username and password may be different so if you have issues here that is where you’ll need to look
Create the database:
rails db:create
Start the Rails server:
rails server
Generate a Home Controller:
rails generate controller Home index
Set the root route: Open the config/routes.rb
file and set the root route to the index
action of the Home
controller:
Rails.application.routes.draw do
root 'home#index'
end
Create the Landing Page Content: Open the app/views/home/index.html.erb
file and add the following HTML code with Tailwind CSS classes to create a pirate-themed landing page:
<div class="min-h-screen bg-blue-900 flex items-center justify-center">
<div class="max-w-2xl bg-gray-800 text-white p-10 rounded-lg shadow-lg">
<h1 class="text-5xl font-bold mb-4 text-center">Ahoy, Matey!</h1>
<p class="text-xl mb-6 text-center">Welcome to Pirate App, the ultimate pirate-themed adventure on the high seas!</p>
<div class="flex justify-center mb-6">
<img src="https://example.com/pirate-ship.jpg" alt="Pirate Ship" class="w-full h-auto rounded-lg shadow-md">
</div>
<div class="text-center">
<a href="#get-started" class="bg-yellow-500 text-black font-bold py-2 px-4 rounded hover:bg-yellow-600">Get Started</a>
</div>
</div>
</div>
Note: Replace the image with one of your own.
Add Navigation Bar: Update app/views/layouts/application.html.erb
to include a simple navigation bar and footer:
<!DOCTYPE html>
<html>
<head>
<title>PirateApp</title>
<%= csrf_meta_tags %>
<%= csp_meta_tag %>
<%= stylesheet_link_tag "application", "data-turbo-track": "reload" %>
<%= javascript_include_tag "application", "data-turbo-track": "reload", defer: true %>
</head>
<body class="bg-blue-900 text-white">
<header class="bg-gray-800 p-4">
<div class="container mx-auto flex justify-between items-center">
<h1 class="text-2xl font-bold">PirateApp</h1>
<nav>
<ul class="flex space-x-4">
<li><a href="/" class="hover:text-yellow-500">Home</a></li>
</ul>
</nav>
</div>
</header>
<%= yield %>
<footer class="bg-gray-800 p-4 mt-10">
<div class="container mx-auto text-center">
<p>© 2024 PirateApp. All rights reserved.</p>
</div>
</footer>
</body>
</html>
With these steps, you will have a simple pirate-themed landing page for your Rails application using Tailwind CSS, complete with navigation and footer.
Avast! Ye now have a Rails application with PostgreSQL and Tailwind CSS ready to set sail!
Configuring PostgreSQL for a Rails application involves setting up the config/database.yml
file. This file tells Rails how to connect to your PostgreSQL database in different environments (development, test, and production). Here’s a detailed explanation of the configuration process and how it works in the context of a Rails application.
database.yml
The config/database.yml
file contains the database configuration for different environments. Each environment (development, test, and production) can have its own settings. Here’s the structure and explanation:
default: &default
adapter: postgresql
encoding: unicode
pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
username: postgres
password: postgres
host: localhost
development:
<<: *default
database: pirate_app_development
test:
<<: *default
database: pirate_app_test
production:
<<: *default
database: pirate_app_production
username: pirate_app
password: <%= ENV['PIRATE_APP_DATABASE_PASSWORD'] %>
default: &default
adapter: postgresql
encoding: unicode
pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
username: postgres
password: postgres
host: localhost
default: &default
: Defines a set of default settings that can be reused across different environments. The &default
is a YAML anchor that allows these settings to be referenced elsewhere in the file.adapter: postgresql
: Specifies that PostgreSQL is the database adapter to be used.encoding: unicode
: Sets the character encoding for the database to Unicode, which supports international characters.pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
: Sets the database connection pool size. It fetches the value from the RAILS_MAX_THREADS
environment variable, defaulting to 5 if not set. The connection pool is the number of connections Rails maintains to the database.username: postgres
: The database username for connecting to PostgreSQL.password: postgres
: The database password for the given username.host: localhost
: Specifies that the database is hosted on the local machine.development:
<<: *default
database: pirate_app_development
<<: *default
: Inherits all the settings from the default
section using the YAML alias *default
.database: pirate_app_development
: Specifies the name of the development database. Rails will connect to this database when running in development mode.test:
<<: *default
database: pirate_app_test
<<: *default
: Inherits all the settings from the default
section.database: pirate_app_test
: Specifies the name of the test database. Rails uses this database when running tests.production:
<<: *default
database: pirate_app_production
username: pirate_app
password: <%= ENV['PIRATE_APP_DATABASE_PASSWORD'] %>
<<: *default
: Inherits all the settings from the default
section.database: pirate_app_production
: Specifies the name of the production database.username: pirate_app
: The database username for production. This should be different from the development and test usernames for security reasons.password: <%= ENV['PIRATE_APP_DATABASE_PASSWORD'] %>
: Fetches the database password from an environment variable. This ensures sensitive information is not hardcoded in the file.Using environment variables for sensitive information (like database passwords) is a best practice. It keeps these details secure and allows for easier changes across different environments (e.g., staging, production).
Setting Environment Variables:
On Unix-like systems (macOS, Linux), you can set environment variables in your shell configuration file (.bashrc
, .zshrc
, etc.):
export PIRATE_APP_DATABASE_PASSWORD=your_secure_password
On Windows, you can set environment variables using the set
command:
set PIRATE_APP_DATABASE_PASSWORD=your_secure_password
Once the config/database.yml
file is properly configured, you can create the database and start the Rails server.
Create the database:
rails db:create
This command will create the databases specified in the database.yml
file for the current environment.
Start the Rails server:
rails server
This command starts the Rails application. The server will use the database configuration for the current environment (development by default).
The config/database.yml
file is a critical part of configuring your Rails application to work with PostgreSQL. It specifies how Rails connects to the database in different environments, using settings inherited from a default configuration. By leveraging environment variables, you can securely manage sensitive information like database passwords. Once configured, you can create the database and start the Rails server to begin development.
Even the most seasoned pirates encounter rough seas. If ye run into trouble while setting up yer Rails project, here be some common issues and troubleshooting steps to help ye navigate through the storm.
1. Ruby and Rails Installation Problems:
ruby -v
and rails -v
. Ensure the version manager (RVM, rbenv, etc.) is properly configured in your shell profile (.zshrc
or .bashrc
). Restart your terminal or run source ~/.zshrc
or source ~/.bashrc
.2. Bundler Errors:
gem install bundler
and then bundle install
. Check for any specific gem installation errors and ensure all dependencies are met.1. PostgreSQL Connection Problems:
config/database.yml
file for correct database credentials. Test the connection with psql -U postgres -h localhost
. Ensure the pg
gem is installed by running gem install pg
.2. Database Creation Failures:
rails db:create
.
username
and password
in config/database.yml
match your PostgreSQL configuration.1. Server Not Starting:
log/development.log
). Ensure all necessary gems are installed and the database is properly configured. Run rails db:migrate
to apply any pending migrations.2. Port Conflicts:
lsof -i :3000
to identify and kill conflicting processes.1. Docker Build Failures:
docker build --no-cache .
to rebuild the image without using the cache.2. Container Connection Problems:
docker-compose.yml
configuration. Ensure the services are correctly defined and linked. Use docker-compose logs
to inspect service logs for errors. Check environment variables for proper database connection details.1. Missing Gem Errors:
GemNotFound
or LoadError
.
bundle install
to install missing gems. Ensure the gem is listed in the Gemfile
. If using private gems, verify authentication settings.2. Asset Compilation Failures:
RAILS_ENV=production rails assets:precompile
for a more detailed error output.1. Rails Guides and Documentation:
2. Stack Overflow:
ruby-on-rails
, postgresql
, docker
, and tailwind-css
to find relevant solutions.3. GitHub Issues:
4. Community Forums and Chat:
By following these troubleshooting steps and utilizing available resources, ye’ll be better equipped to handle any issues that arise during yer Rails and Docker adventure. Happy sailing!
Ye’ve successfully set up Ruby and Rails on yer ship, configured PostgreSQL for yer database needs, and hoisted the Tailwind CSS sails. With yer environment shipshape, ye’re ready to embark on the next leg of yer Rails adventure. Now, it’s time to navigate the seas of development, deployment, and beyond!
To manage multiple versions of Node.js efficiently, you can use Node Version Manager (NVM). Here’s how to install NVM and set it up with the LTS version of Node.js (v20.15.1):
Install & Update Script:
You can install or update NVM using the install script. Use either of the following commands to download and run the script:
curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.39.7/install.sh | bash
wget -qO- https://raw.githubusercontent.com/nvm-sh/nvm/v0.39.7/install.sh | bash
Running either of these commands will clone the NVM repository to ~/.nvm
and attempt to add the following lines to your profile file (~/.bash_profile
, ~/.zshrc
, ~/.profile
, or ~/.bashrc
):
export NVM_DIR="$([ -z "${XDG_CONFIG_HOME-}" ] && printf %s "${HOME}/.nvm" || printf %s "${XDG_CONFIG_HOME}/nvm")"
[ -s "$NVM_DIR/nvm.sh" ] && \. "$NVM_DIR/nvm.sh" # This loads nvm
Load NVM:
After installation, you might need to restart your terminal or source your profile file to load NVM:
# For bash
source ~/.bashrc
# For zsh
source ~/.zshrc
# For ksh
. ~/.profile
Verify Installation:
To verify that NVM has been installed, run:
command -v nvm
This should print nvm
if the installation was successful.
Install Node.js LTS Version (v20.15.1):
Once NVM is installed, you can install the LTS version of Node.js (v20.15.1):
nvm install 20.15.1
Use the LTS Node.js Version:
To use the LTS version of Node.js, run:
nvm use 20.15.1
Set the LTS Node.js Version as Default:
To set the LTS version of Node.js as the default, run:
nvm alias default 20.15.1
If you encounter issues where nvm
is not found after installation:
Ensure that the profile file is sourced properly.
Restart your terminal.
Manually add the following lines to your profile file and source it:
export NVM_DIR="$([ -z "${XDG_CONFIG_HOME-}" ] && printf %s "${HOME}/.nvm" || printf %s "${XDG_CONFIG_HOME}/nvm")"
[ -s "$NVM_DIR/nvm.sh" ] && \. "$NVM_DIR/nvm.sh" # This loads nvm
For macOS users, especially those with Apple Silicon chips:
Ensure you have Xcode command line tools installed:
xcode-select --install
If you face issues, ensure you create the necessary profile files (~/.bash_profile
or ~/.zshrc
) if they don’t exist, and then rerun the install script.
By installing and configuring NVM, you can easily manage multiple versions of Node.js, making your development workflow more flexible and efficient. For this setup, we have used the LTS version v20.15.1 to ensure stability and long-term support.
In the next chapter, we’ll delve deeper into organizing yer Rails project structure, setting up version control with Git, and managing private gems and npm packages. Stay the course, and ye’ll be a Rails and DevOps pirate in no time!
Ahoy, me hearties! Now that we’ve set sail with our Ruby on Rails application, it’s time to chart the course of our project structure. Understanding the directory layout of a Rails application is crucial for navigating and managing your code effectively.
When ye create a new Rails application, Rails generates a standard directory structure. Here’s a brief overview of the key directories and their purposes:
app/: Contains the core application code. This is where ye’ll find your models, views, controllers, helpers, mailers, and jobs.
bin/: Contains executable files like rails and rake.
config/: Houses configuration files for the application, including database, routes, initializers, and environments.
db/: Manages database-related files.
log/: Stores application log files.
public/: Holds static files like error pages and assets.
test/ or spec/: Manages test or spec files for testing the application.
tmp/: Contains temporary files like cache and pid files.
Understanding this structure will help ye navigate and organize yer code effectively.
Now, let’s set up version control to keep our codebase shipshape. Git be the tool of choice for version control, and GitHub be our treasure chest for storing code.
If ye haven’t already, head over to GitHub and sign up for an account.
Create a New Repository:
Once ye have a repository, follow these steps to get yer code into the cloud.
Initialize Git:
git init --initial-branch=main
Commit Early and Often: It be best practice to commit yer changes frequently with clear and concise commit messages. This makes it easier to track changes and roll back if needed.
git add .
git commit -m "Yargh Mateys"
Add Remote Repository: Add the GitHub repository as a remote to yer local repository. Replace your-username
and your-repo
with yer GitHub username and repository name.
git remote add origin git@github.com:loftwah-demo/pirate_app.git
Push to GitHub: Push yer local commits to the remote repository on GitHub.
git branch -M main
git push -u origin main
Use Branches: Create branches for new features or bug fixes. This keeps the main branch clean and stable.
git checkout -b feature/new-feature
Merge with Pull Requests: Use pull requests to merge changes into the main branch. This allows for code review and discussion before changes are integrated.
The .gitignore file be crucial for managing what files Git tracks. It helps keep unnecessary files out of your repository, reducing clutter and protecting sensitive information.
Never commit sensitive data such as API keys, passwords, or configuration files containing secrets. Use environment variables or a secrets management tool instead.
For Rails applications, the .env
file is commonly used to manage environment-specific configurations. However, remember to add .env
to your .gitignore
to prevent it from being tracked by Git.
# .gitignore
.env
In our adventure, we’ll create our own private gems and npm packages that we can use in our Rails application. This be an essential skill for any Rails developer, as it allows for modular and reusable code across multiple projects.
Set Up the Gem Structure: Create a new directory for your gem:
mkdir my_private_gem
cd my_private_gem
bundle gem .
Edit the Gem Specification: Open the my_private_gem.gemspec
file and fill in the necessary details:
Gem::Specification.new do |spec|
spec.name = "my_private_gem"
spec.version = "0.1.0"
spec.authors = ["Your Name"]
spec.email = ["your.email@example.com"]
spec.summary = "A private gem for demonstration purposes"
spec.description = "This gem is used to demonstrate using private gems in a Rails application"
spec.homepage = "https://github.com/loftwah-demo/my_private_gem"
spec.license = "MIT"
spec.files = Dir["lib/**/*.rb"]
spec.require_paths = ["lib"]
end
Add Functionality: Create a simple functionality in lib/my_private_gem.rb
:
module MyPrivateGem
class Error < StandardError; end
def self.hello
"Hello from MyPrivateGem!"
end
end
Commit and Push to GitHub: Initialize a new Git repository and push the gem to a private repository on GitHub:
git init --initial-branch=main
git add .
git commit -m "Initial commit"
git remote add origin git@github.com:loftwah-demo/my_private_gem.git
git branch -M main
git push -u origin main
Note: the following changes are made in the Rails application you started earlier.
To use the private gem in your Rails application, ye’ll need to create a GitHub Personal Access Token (PAT) for authentication.
Create a GitHub PAT:
repo
and read:packages
, then generate the token.Add the Private Gem to Your Rails Application’s Gemfile:
# Gemfile
gem 'my_private_gem', git: 'https://github.com/loftwah-demo/my_private_gem.git'
Configure Bundler to Use the PAT: Create or update your .bundle/config
file to include the GitHub PAT:
bundle config https://github.com/loftwah-demo <your_github_token>
Alternatively, set the environment variable in your shell:
export BUNDLE_GITHUB__COM=<your_github_token>
Install the Gem: Run bundle install
to install the gem:
bundle install
Note: We will cover using this in your Rails application in chapter x
Set Up the npm Package: Create a new directory for your npm package:
mkdir my-private-npm-package
cd my-private-npm-package
npm init -y
Update package.json
: Edit package.json
to include the necessary details:
{
"name": "my-private-npm-package",
"version": "1.0.0",
"main": "index.js",
"scripts": {
"test": "echo \"Error: no test specified\" && exit 1"
},
"keywords": ["loftwah", "linux", "for", "pirates"],
"author": "Dean Lofts",
"license": "ISC",
"description": "A private package for Linux for Pirates!"
}
Add Functionality: Create a simple functionality in index.js
:
function helloFromNpm() {
return "Hello from my private npm package!";
}
module.exports = { helloFromNpm };
Commit and Push to GitHub: Initialize a new Git repository and push the package to a private repository on GitHub:
git init --initial-branch=main
git add .
git commit -m "Initial commit"
git remote add origin git@github.com:loftwah-demo/my-private-npm-package.git
git push -u origin main
Navigate to Your Rails Application Directory:
cd ../pirate_app
Create a package.json
File:
npm init -y
Update package.json
to Include the Private Package:
Open the generated package.json
file in a text editor and modify it to include your private package:
{
"name": "pirate_app",
"version": "1.0.0",
"description": "This README would normally document whatever steps are necessary to get the application up and running.",
"main": "index.js",
"directories": {
"lib": "lib",
"test": "test"
},
"scripts": {
"test": "echo \"Error: no test specified\" && exit 1"
},
"keywords": [],
"author": "",
"license": "ISC",
"dependencies": {
"my-private-npm-package": "git+https://github.com/loftwah-demo/my-private-npm-package.git"
}
}
Configure npm for Authentication:
Create an .npmrc
file in your Rails application’s root directory to authenticate with GitHub Packages:
//npm.pkg.github.com/:_authToken=${GITHUB_PAT}
Install the Dependencies:
Run npm install
to install the packages defined in package.json
:
npm install
Note: You will be able to see the package in your
node_modules
directory and we will set this up further in chapter 5.
package.json
with the necessary details.package.json
File in Rails App: Initialized a package.json
file and added the private package as a dependency..npmrc
file for GitHub package authentication.npm install
to install the private package.By following these steps, you’ve set up a private npm package, pushed it to GitHub, and configured your Rails application to use this package. This ensures your codebase is well-organized and secure, allowing you to smoothly develop your application.
In the next chapter, we’ll dive into Docker, the mighty ship that’ll carry our Rails application across the seas of deployment. We’ll learn how to write Dockerfiles, build Docker images, and run our Rails app within Docker containers. Stay the course, and ye’ll be a Rails and DevOps pirate in no time!
Ahoy, me hearties! Docker be the sturdy ship that’ll carry ye across the treacherous seas of deployment and development. In this chapter, we’ll set sail with Docker, learnin’ its key concepts and why it’s the vessel of choice for modern developers.
Docker be an open platform for developing, shipping, and running applications. It enables ye to separate yer applications from yer infrastructure, makin’ it easier to deploy and manage them across different environments. Here be why Docker be invaluable:
When ye generate a new Rails project, it comes with a Dockerfile ready to use. However, we had to make some modifications to this default Dockerfile. These changes were necessary to install a private package from GitHub using a Personal Access Token (PAT). Let’s explore these modifications.
To show Rails credentials using the nano editor:
EDITOR=nano bin/rails credentials:show
Note: you need this one to get your SECRET_KEY_BASE
To run the Docker container:
docker run -e SECRET_KEY_BASE=<my-key> -p 3000:3000 pirate_app
To build the Docker image using a secret token:
GITHUB_TOKEN=<my-token> docker buildx build --secret id=GITHUB_TOKEN -t pirate_app .
Here’s the modified Dockerfile with the necessary changes to handle secrets and build the application:
# syntax=docker/dockerfile:1
# Make sure RUBY_VERSION matches the Ruby version in .ruby-version and Gemfile
ARG RUBY_VERSION=3.3.0
FROM registry.docker.com/library/ruby:$RUBY_VERSION-slim AS base
# Rails app lives here
WORKDIR /rails
# Set production environment
ENV RAILS_ENV="production" \
BUNDLE_DEPLOYMENT="1" \
BUNDLE_PATH="/usr/local/bundle" \
BUNDLE_WITHOUT="development"
# Throw-away build stage to reduce size of final image
FROM base as build
# Install packages needed to build gems
RUN apt-get update -qq && \
apt-get install --no-install-recommends -y build-essential git libpq-dev libvips pkg-config
# Install application gems
COPY Gemfile Gemfile.lock ./
# Use secret to access GitHub token to install private packages
RUN --mount=type=secret,id=GITHUB_TOKEN \
GITHUB_TOKEN=${GITHUB_TOKEN} && \
git config --global url."https://${GITHUB_TOKEN}@github.com/".insteadOf "https://github.com/" && \
bundle install && \
rm -rf ~/.bundle/ "${BUNDLE_PATH}"/ruby/*/cache "${BUNDLE_PATH}"/ruby/*/bundler/gems/*/.git && \
bundle exec bootsnap precompile --gemfile
# Copy application code
COPY . .
# Precompile bootsnap code for faster boot times
RUN bundle exec bootsnap precompile app/ lib/
# Precompiling assets for production without requiring secret RAILS_MASTER_KEY
RUN SECRET_KEY_BASE_DUMMY=1 ./bin/rails assets:precompile
# Final stage for app image
FROM base
# Install packages needed for deployment
RUN apt-get update -qq && \
apt-get install --no-install-recommends -y curl libvips postgresql-client && \
rm -rf /var/lib/apt/lists /var/cache/apt/archives
# Copy built artifacts: gems, application
COPY --from=build /usr/local/bundle /usr/local/bundle
COPY --from=build /rails /rails
# Run and own only the runtime files as a non-root user for security
RUN useradd rails --create-home --shell /bin/bash && \
chown -R rails:rails db log storage tmp
USER rails:rails
# Entrypoint prepares the database.
ENTRYPOINT ["/rails/bin/docker-entrypoint"]
# Start the server by default, this can be overwritten at runtime
EXPOSE 3000
CMD ["./bin/rails", "server"]
The changes we made are here:
# Use secret to access GitHub token to install private packages
RUN --mount=type=secret,id=GITHUB_TOKEN \
GITHUB_TOKEN=${GITHUB_TOKEN} && \
git config --global url."https://${GITHUB_TOKEN}@github.com/".insteadOf "https://github.com/" && \
bundle install && \
rm -rf ~/.bundle/ "${BUNDLE_PATH}"/ruby/*/cache "${BUNDLE_PATH}"/ruby/*/bundler/gems/*/.git && \
bundle exec bootsnap precompile --gemfile
We made these changes to the Dockerfile to handle the installation of private packages from GitHub using a Personal Access Token (PAT). This approach ensures that our application can securely access and install these private packages during the Docker build process.
Now that we’ve modified our Dockerfile, let’s build and run our Docker containers locally.
Build the Docker Image:
GITHUB_TOKEN=<my-token> docker buildx build --secret id=GITHUB_TOKEN -t pirate_app .
Run the Docker Container:
docker run -e SECRET_KEY_BASE=<my-key> -p 3000:3000 pirate_app
Yer Rails application should now be built into a Docker container. However, since our application relies on PostgreSQL, it won’t be runnin’ properly just yet. In the next chapter, we’ll dive into Docker Compose to orchestrate multiple services, including our Rails app and PostgreSQL database.
Let’s walk through the Dockerfile step-by-step to understand each part and how it helps in building and running your Rails application.
# syntax=docker/dockerfile:1
# Make sure RUBY_VERSION matches the Ruby version in .ruby-version and Gemfile
ARG RUBY_VERSION=3.3.0
FROM registry.docker.com/library/ruby:$RUBY_VERSION-slim AS base
# Rails app lives here
WORKDIR /rails
# Set production environment
ENV RAILS_ENV="production" \
BUNDLE_DEPLOYMENT="1" \
BUNDLE_PATH="/usr/local/bundle" \
BUNDLE_WITHOUT="development"
Base Image: We start with a base image for Ruby. The version is specified using the ARG RUBY_VERSION
argument, allowing flexibility if you need to change the Ruby version.
Working Directory: The WORKDIR /rails
command sets the working directory inside the container to /rails
, where our Rails application will reside.
Environment Variables:
RAILS_ENV="production"
: Sets the Rails environment to production.BUNDLE_DEPLOYMENT="1"
and BUNDLE_PATH="/usr/local/bundle"
: Configure Bundler to install gems in deployment mode and to a specific path.BUNDLE_WITHOUT="development"
: Excludes the development group from the bundle install.# Throw-away build stage to reduce size of final image
FROM base as build
# Install packages needed to build gems
RUN apt-get update -qq && \
apt-get install --no-install-recommends -y build-essential git libpq-dev libvips pkg-config
# Install application gems
COPY Gemfile Gemfile.lock ./
# Use secret to access GitHub token to install private packages
RUN --mount=type=secret,id=GITHUB_TOKEN \
GITHUB_TOKEN=${GITHUB_TOKEN} && \
git config --global url."https://${GITHUB_TOKEN}@github.com/".insteadOf "https://github.com/" && \
bundle install && \
rm -rf ~/.bundle/ "${BUNDLE_PATH}"/ruby/*/cache "${BUNDLE_PATH}"/ruby/*/bundler/gems/*/.git && \
bundle exec bootsnap precompile --gemfile
# Copy application code
COPY . .
# Precompile bootsnap code for faster boot times
RUN bundle exec bootsnap precompile app/ lib/
# Precompiling assets for production without requiring secret RAILS_MASTER_KEY
RUN SECRET_KEY_BASE_DUMMY=1 ./bin/rails assets:precompile
Build Stage: This stage is used to build the application and its dependencies.
Install Packages: The RUN apt-get install
command installs necessary packages for building Ruby gems, such as build-essential
, git
, libpq-dev
, libvips
, and pkg-config
.
Install Gems:
COPY Gemfile Gemfile.lock ./
: Copies the Gemfile and Gemfile.lock into the container.RUN --mount=type=secret,id=GITHUB_TOKEN ... bundle install
: Uses a GitHub token to install private gems, ensuring the token remains secret during the build.rm -rf ~/.bundle/ "${BUNDLE_PATH}"/ruby/*/cache "${BUNDLE_PATH}"/ruby/*/bundler/gems/*/.git
: Cleans up unnecessary files to reduce the image size.bundle exec bootsnap precompile --gemfile
: Precompiles bootsnap code for faster boot times.Copy Application Code: COPY . .
copies the entire application code into the container.
Precompile Assets: Precompiles Rails assets for production without requiring the master key by using a dummy key.
# Final stage for app image
FROM base
# Install packages needed for deployment
RUN apt-get update -qq && \
apt-get install --no-install-recommends -y curl libvips postgresql-client && \
rm -rf /var/lib/apt/lists /var/cache/apt/archives
# Copy built artifacts: gems, application
COPY --from=build /usr/local/bundle /usr/local/bundle
COPY --from=build /rails /rails
# Run and own only the runtime files as a non-root user for security
RUN useradd rails --create-home --shell /bin/bash && \
chown -R rails:rails db log storage tmp
USER rails:rails
# Entrypoint prepares the database.
ENTRYPOINT ["/rails/bin/docker-entrypoint"]
# Start the server by default, this can be overwritten at runtime
EXPOSE 3000
CMD ["./bin/rails", "server"]
Final Stage: This stage creates the final image that will be used to run the application.
Install Deployment Packages: Installs necessary packages for running the Rails application, such as curl
, libvips
, and postgresql-client
.
Copy Artifacts: Copies the built artifacts (gems and application code) from the build stage to the final image.
Set Up User and Permissions:
useradd rails --create-home --shell /bin/bash
: Adds a non-root user named rails
for security.chown -R rails:rails db log storage tmp
: Changes ownership of important directories to the rails
user.USER rails:rails
: Switches to the rails
user for running the application.Entrypoint and CMD:
ENTRYPOINT ["/rails/bin/docker-entrypoint"]
: Sets the entrypoint script to prepare the database.EXPOSE 3000
: Exposes port 3000 for the application.CMD ["./bin/rails", "server"]
: Starts the Rails server by default.Now that we’ve modified our Dockerfile, let’s build and run our Docker containers locally.
Build the Docker Image:
GITHUB_TOKEN=<my-token> docker buildx build --secret id=GITHUB_TOKEN -t pirate_app .
Run the Docker Container:
docker run -e SECRET_KEY_BASE=<my-key> -p 3000:3000 pirate_app
Yer Rails application should now be built into a Docker container. However, since our application relies on PostgreSQL, it won’t be runnin’ properly just yet. In the next chapter, we’ll dive into Docker Compose to orchestrate multiple services, including our Rails app and PostgreSQL database.
Ye’ve successfully explored the provided Dockerfile for yer Rails application, made necessary modifications to handle private package installations, and run yer application within a Docker container. With Docker as yer ship, ye be ready to navigate the seas of deployment and beyond!
In the next chapter, we’ll dive into Docker Compose, coordinatin’ multiple services like a true pirate captain. We’ll set up a docker-compose.yml
file, configure services for Rails, PostgreSQL, and Redis, and manage environment variables. Stay the course, and ye’ll be a Rails and DevOps pirate in no time!
Docker Compose is a tool for defining and running multi-container Docker applications. With Compose, you use a YAML file to configure your application’s services. Then, with a single command, you create and start all the services from your configuration. This simplifies orchestration, streamlines the development process, and ensures consistency across different stages of development and deployment.
Docker Compose uses a docker-compose.yml
file to define and configure multiple services. We’ll set up a multi-service application for Rails and PostgreSQL. Additionally, we’ll handle environment variables securely using .env
files.
To manage your development environment effectively, we’ll create a docker-compose.yml
file. This file will configure services for Rails, PostgreSQL, and handle secrets securely.
The original Dockerfile is optimized for production environments:
Here’s the production Dockerfile:
# syntax=docker/dockerfile:1
# Make sure RUBY_VERSION matches the Ruby version in .ruby-version and Gemfile
ARG RUBY_VERSION=3.3.0
FROM registry.docker.com/library/ruby:$RUBY_VERSION-slim AS base
# Rails app lives here
WORKDIR /rails
# Set production environment
ENV RAILS_ENV="production" \
BUNDLE_DEPLOYMENT="1" \
BUNDLE_PATH="/usr/local/bundle" \
BUNDLE_WITHOUT="development"
# Throw-away build stage to reduce size of final image
FROM base AS build
# Install packages needed to build gems
RUN apt-get update -qq && \
apt-get install --no-install-recommends -y build-essential git libpq-dev libvips pkg-config
# Install application gems
COPY Gemfile Gemfile.lock ./
# Use secret to access GitHub token
RUN --mount=type=bind,target=. \
--mount=type=secret,id=GITHUB_TOKEN \
GITHUB_TOKEN=$(cat /run/secrets/GITHUB_TOKEN) && \
git config --global url."https://${GITHUB_TOKEN}@github.com/".insteadOf "https://github.com/" && \
bundle install && \
rm -rf ~/.bundle/ "${BUNDLE_PATH}"/ruby/*/cache "${BUNDLE_PATH}"/ruby/*/bundler/gems/*/.git && \
bundle exec bootsnap precompile --gemfile
# Copy application code
COPY . .
# Precompile bootsnap code for faster boot times
RUN bundle exec bootsnap precompile app/ lib/
# Precompiling assets for production without requiring secret RAILS_MASTER_KEY
RUN SECRET_KEY_BASE_DUMMY=1 ./bin/rails assets:precompile
# Final stage for app image
FROM base
# Install packages needed for deployment
RUN apt-get update -qq && \
apt-get install --no-install-recommends -y curl libvips postgresql-client && \
rm -rf /var/lib/apt/lists /var/cache/apt/archives
# Copy built artifacts: gems, application
COPY --from=build /usr/local/bundle /usr/local/bundle
COPY --from=build /rails /rails
# Run and own only the runtime files as a non-root user for security
RUN useradd rails --create-home --shell /bin/bash && \
chown -R rails:rails db log storage tmp
USER rails:rails
# Entrypoint prepares the database.
ENTRYPOINT ["/rails/bin/docker-entrypoint"]
# Start the server by default, this can be overwritten at runtime
EXPOSE 3000
CMD ["./bin/rails", "server"]
Using the same Dockerfile for both production and development can lead to inefficiencies and complexities. The development Dockerfile (Dockerfile.dev
) is optimized for:
Here’s the development Dockerfile:
# Dockerfile.dev
# syntax=docker/dockerfile:1
ARG RUBY_VERSION=3.3.0
FROM registry.docker.com/library/ruby:$RUBY_VERSION-slim AS base
WORKDIR /rails
# Set development environment
ENV RAILS_ENV="development" \
BUNDLE_PATH="/usr/local/bundle" \
# Install packages needed to build gems and development tools
RUN apt-get update -qq && \
apt-get install --no-install-recommends -y build-essential git libpq-dev libvips pkg-config nodejs yarn
# Copy only the Gemfiles for installing gems
COPY Gemfile Gemfile.lock ./
# Use secret to access GitHub token for private repositories and install gems
RUN --mount=type=secret,id=GITHUB_TOKEN \
GITHUB_TOKEN=$(cat /run/secrets/GITHUB_TOKEN) && \
git config --global url."https://${GITHUB_TOKEN}@github.com/".insteadOf "https://github.com/" && \
bundle install
# Copy the rest of the application code
COPY . .
# Precompile bootsnap code for faster boot times
RUN bundle exec bootsnap precompile app/ lib/
# Start the server by default
EXPOSE 3000
CMD ["./bin/rails", "server", "-b", "0.0.0.0"]
The docker-compose.yml
file coordinates multiple services needed for the application. Here’s the complete file, which includes configurations for the Rails app and PostgreSQL:
services:
app:
build:
context: .
dockerfile: Dockerfile.dev
secrets:
- GITHUB_TOKEN
environment:
DATABASE_URL: postgres://postgres:postgres@db:5432/pirate_app_development
ports:
- "3000:3000"
volumes:
- .:/rails
depends_on:
- db
db:
image: postgres:16
environment:
POSTGRES_USER: postgres
POSTGRES_PASSWORD: postgres
POSTGRES_DB: pirate_app_development
volumes:
- db_data:/var/lib/postgresql/data
secrets:
GITHUB_TOKEN:
environment: GITHUB_TOKEN
volumes:
db_data:
Using .env
files for environment-specific configurations helps in maintaining different settings for development and production environments. Docker Compose automatically reads the .env
file located in the same directory as the docker-compose.yml
file and uses the variables defined within it.
Ensure your .env
file contains the necessary environment variables:
# .env
GITHUB_TOKEN=<your-github-token>
SECRET_KEY_BASE=<your-secret-key-base>
With the docker-compose.yml
and .env
files set up, you can build and run the development environment using Docker Compose.
To build the services:
docker compose build
To start the services:
docker compose up
Note: Use
docker compose up -d
to run the application in the background.
Dockerfile.dev
): Tailored for development with necessary development tools and rapid iteration support..env
file for secure and environment-specific configurations.By following these instructions, you can effectively use Docker Compose to manage your development environment, leveraging the power of Docker to ensure consistency and ease of setup.
Ahoy, me hearties! Now that we’ve set up our Rails application, it’s time to put our private packages to use. This chapter covers integrating private Ruby gems and npm packages into our Rails application.
Let’s use the private Ruby gem we created earlier in our Rails application (part of this will already be done if you were following along).
Add the Gem to Your Gemfile:
gem 'my_private_gem', git: 'https://github.com/loftwah-demo/my_private_gem.git'
Configure Bundler to Use the PAT:
bundle config https://github.com <your_github_token>
Install the Gem:
bundle install
Use the Gem in Your Rails Application: In app/controllers/application_controller.rb
, add:
class ApplicationController < ActionController::Base
def test_my_private_gem
render plain: MyPrivateGem.hello
end
end
Add a Route to Test the Gem: In config/routes.rb
, add:
Rails.application.routes.draw do
get 'test_my_private_gem', to: 'application#test_my_private_gem'
end
Verify the Gem is Working: Start your Rails server and navigate to http://localhost:3000/test_my_private_gem
. You should see:
Hello from MyPrivateGem!
Let’s integrate the private npm package into our Rails application.
Navigate to Your Rails Application Directory:
cd ../pirate_app
Create a package.json
File (we may have already done this if you’re following along):
npm init -y
Update package.json
to Include the Private Package:
{
"name": "pirate_app",
"version": "1.0.0",
"dependencies": {
"my-private-npm-package": "git+https://github.com/loftwah-demo/my-private-npm-package.git"
}
}
Configure npm for Authentication: Create an .npmrc
file in your Rails application’s root directory:
//npm.pkg.github.com/:_authToken=${GITHUB_TOKEN}
Install the Dependencies:
npm install
Install the vite_rails
Gem:
Add the vite_rails
gem to your Gemfile:
gem 'vite_rails'
Then run bundle install
:
bundle install
Install Vite with Rails:
Initialize Vite in your Rails application:
bundle exec vite install
Install npm dependencies and build the Vite project:
npm ci
npx vite build
Run Rails and Check:
Start the Rails server and Vite development server:
rails s
bin/vite dev
Shut Down Rails and Vite:
Before proceeding, shut down the Rails server and Vite development server by pressing Ctrl+C
in the terminal where they are running.
Install Foreman (Development Only):
Foreman is a tool to manage Procfile-based applications. Add it to your Gemfile for the development group:
group :development do
gem 'foreman'
end
Then run bundle install
:
bundle install
Set Up Procfile.dev
:
If not already present, create a Procfile.dev
in the root of your project directory with the following content:
web: bin/rails server
css: bin/rails tailwindcss:watch
vite: bin/vite dev
Run Foreman:
Use Foreman to start all processes defined in Procfile.dev
:
bin/bundle exec foreman start -f Procfile.dev
This will start your Rails server, Tailwind CSS watcher, and Vite development server all at once, making your development workflow more efficient.
Shut Down Foreman:
Before proceeding, shut down Foreman and any running processes by pressing Ctrl+C
in the terminal where they are running.
Update docker-compose.yml
:
To run the necessary processes using Docker, update your docker-compose.yml
file as follows:
services:
web:
build:
context: .
dockerfile: Dockerfile.dev
secrets:
- GITHUB_TOKEN
environment:
SECRET_KEY_BASE: ${SECRET_KEY_BASE}
DATABASE_URL: postgres://postgres:postgres@db:5432/pirate_app_development
ports:
- "3000:3000"
volumes:
- .:/rails
depends_on:
- db
command: bin/rails server -b 0.0.0.0
vite:
build:
context: .
dockerfile: Dockerfile.dev
secrets:
- GITHUB_TOKEN
volumes:
- .:/rails
depends_on:
- web
command: bin/vite dev
db:
image: postgres:16
environment:
POSTGRES_USER: postgres
POSTGRES_PASSWORD: postgres
POSTGRES_DB: pirate_app_development
volumes:
- db_data:/var/lib/postgresql/data
secrets:
GITHUB_TOKEN:
environment: GITHUB_TOKEN
volumes:
db_data:
Note: I use
foreman
to develop locally and this is my preference, withdocker compose
being a secondary option.
You’ve successfully set up Vite with Rails using the vite_rails
gem and integrated your development environment to use Docker for managing multiple processes. This setup ensures that your JavaScript is bundled correctly and can take advantage of Vite’s features.
In the next chapter, we’ll dive into secure authentication with SSH and HTTPS, managing secrets, and using GitHub Personal Access Tokens (PATs) for secure access. Stay the course, and you’ll be a Rails and DevOps expert in no time!
Arrr, ye landlubbers, we be needin’ to set sail with secure authentication using SSH keys in Docker. Here be the steps to hoist the Jolly Roger and fetch private treasures (repositories):
Generate an SSH Key: We be generatin’ a new key so we don’t mess with yer existing id_rsa
.
ssh-keygen -t rsa -b 4096 -f ~/.ssh/id_pirate_key -C "your_email@example.com"
This command creates a new key pair (id_pirate_key
and id_pirate_key.pub
).
Add the SSH Key to Your SSH Agent: The SSH agent be a daemon that holds yer private keys in memory. We be usin’ it so yer private keys don’t be needin’ to be entered every time.
eval $(ssh-agent -s)
ssh-add ~/.ssh/id_pirate_key
Add Your SSH Key to GitHub: Copy the public key to yer clipboard and add it to yer GitHub account.
cat ~/.ssh/id_pirate_key.pub
Swab the decks and prepare to clone private repositories using SSH mounts in Docker. This be the Dockerfile we be usin’ to fetch our private treasures.
# syntax=docker/dockerfile:1
# Make sure RUBY_VERSION matches the Ruby version in .ruby-version and Gemfile
ARG RUBY_VERSION=3.3.0
FROM registry.docker.com/library/ruby:$RUBY_VERSION-slim AS base
# Rails app lives here
WORKDIR /rails
# Set production environment
ENV RAILS_ENV="production" \
BUNDLE_DEPLOYMENT="1" \
BUNDLE_PATH="/usr/local/bundle" \
BUNDLE_WITHOUT="development"
# Throw-away build stage to reduce size of final image
FROM base AS build
# Install packages needed to build gems
RUN apt-get update -qq && \
apt-get install --no-install-recommends -y build-essential git libpq-dev libvips pkg-config openssh-client
# Add SSH key to the build environment
ADD id_pirate_key /root/.ssh/id_pirate_key
RUN chmod 600 /root/.ssh/id_pirate_key && \
ssh-keyscan github.com >> /root/.ssh/known_hosts
# Install application gems
COPY Gemfile Gemfile.lock ./
# Use SSH to access private GitHub repo
RUN --mount=type=ssh \
GIT_SSH_COMMAND='ssh -i /root/.ssh/id_pirate_key' bundle install && \
rm -rf ~/.bundle/ "${BUNDLE_PATH}"/ruby/*/cache "${BUNDLE_PATH}"/ruby/*/bundler/gems/*/.git && \
bundle exec bootsnap precompile --gemfile
# Copy application code
COPY . .
# Precompile bootsnap code for faster boot times
RUN bundle exec bootsnap precompile app/ lib/
# Precompiling assets for production without requiring secret RAILS_MASTER_KEY
RUN SECRET_KEY_BASE_DUMMY=1 ./bin/rails assets:precompile
# Final stage for app image
FROM base
# Install packages needed for deployment
RUN apt-get update -qq && \
apt-get install --no-install-recommends -y curl libvips postgresql-client && \
rm -rf /var/lib/apt/lists /var/cache/apt/archives
# Copy built artifacts: gems, application
COPY --from=build /usr/local/bundle /usr/local/bundle
COPY --from=build /rails /rails
# Run and own only the runtime files as a non-root user for security
RUN useradd rails --create-home --shell /bin/bash && \
chown -R rails:rails db log storage tmp
USER rails:rails
# Entrypoint prepares the database.
ENTRYPOINT ["/rails/bin/docker-entrypoint"]
# Start the server by default, this can be overwritten at runtime
EXPOSE 3000
CMD ["./bin/rails", "server"]
id_pirate_key
to avoid conflicts with existing keys. This key be added to yer SSH agent for secure use.ADD
command to include the SSH key in the Docker build environment and RUN --mount=type=ssh
to securely clone private repositories.With this knowledge, ye be ready to set sail with secure SSH authentication in Docker. Remember, a true pirate guards his keys well and uses them wisely to fetch the richest treasures from the seas of code!
Note: I tend to avoid using SSH in my Docker images and containers.
Ahoy, mateys! In this chapter, we’ll dive into the importance of Continuous Integration (CI) and Continuous Deployment (CD). These practices ensure that your code is always in a deployable state, making it easier to catch bugs early and deploy new features quickly and reliably.
Why CI/CD?
Add RSpec to your Gemfile
:
group :development, :test do
gem "rspec-rails"
end
group :test do
gem "capybara"
gem "selenium-webdriver"
gem "factory_bot_rails"
gem "faker"
end
Install the gems:
bundle install
Generate RSpec configuration:
rails generate rspec:install
Run RSpec to ensure it’s set up correctly:
bundle exec rspec
Create a GitHub Actions Workflow:
.github/workflows
directory named ci.yml
.Define the Workflow for Testing:
name: CI
on:
push:
branches:
- main
pull_request:
branches:
- main
jobs:
test:
runs-on: ubuntu-latest
services:
postgres:
image: postgres:16
ports:
- 5432:5432
env:
POSTGRES_DB: pirate_app_test
POSTGRES_USER: postgres
POSTGRES_PASSWORD: postgres
steps:
- uses: actions/checkout@v4
- name: Set up Ruby
uses: ruby/setup-ruby@v1
with:
ruby-version: 3.3.0
- name: Install dependencies
env:
BUNDLE_GITHUB__COM: $
run: |
gem install bundler
bundle config set --local github.com "x-access-token:$"
bundle install
- name: Set up database
run: |
bundle exec rails db:create db:migrate
env:
RAILS_ENV: test
POSTGRES_USER: postgres
POSTGRES_PASSWORD: postgres
- name: Run tests
run: bundle exec rspec
env:
RAILS_ENV: test
Add GH_PAT
as a Repository Secret:
Settings
> Secrets and variables
> Actions
.New repository secret
.GH_PAT
and paste your personal access token.repo
and package:read
scopes.Create a GitHub Actions Workflow:
ci.yml
in the .github/workflows
directory.Define the Workflow for Testing:
actions/checkout@v4
to ensure compatibility with the latest Node.js versions.ruby/setup-ruby@v1
to set up Ruby 3.3.0.BUNDLE_GITHUB__COM
environment variable to authenticate with the personal access token (GH_PAT
).bundle install
.bundle exec rails db:create db:migrate
.bundle exec rspec
.Add GH_PAT
as a Repository Secret:
By following these steps, you’ll ensure that your CI/CD pipeline is set up correctly to test your Rails application with RSpec, and that your private gem repository is accessible using the provided personal access token.
doctl
To automate the deployment of your Rails application, we’ll use doctl
to manage DigitalOcean and GitHub Actions to handle the deployment process.
doctl
for DigitalOceanInstall doctl
:
On macOS:
brew install doctl
On Ubuntu:
snap install doctl
Download and install from GitHub for other systems.
Create a DigitalOcean API Token:
doctl
.Authenticate doctl
:
doctl auth init
Generate SSH Keys:
If you don’t already have SSH keys, you can generate them using the following command:
ssh-keygen -t rsa -b 4096 -C "your_email@example.com"
~/.ssh/id_rsa
).Add SSH Key to DigitalOcean:
doctl compute ssh-key import loftwah --public-key-file ~/.ssh/id_rsa.pub
➜ pirate_app git:(main) doctl compute ssh-key import loftwah --public-key-file ~/.ssh/id_rsa.pub
ID Name FingerPrint
42754072 loftwah 76:a5:d8:77:d2:86:52:14:f7:ea:9b:b6:94:f2:b7:fc
Note: The ID from here is what you need below as
.
<KEY-NAME>
with a name for your SSH key.Create a Droplet:
doctl compute droplet create <DROPLET-NAME> --region syd1 --image ubuntu-22-04-x64 --size s-1vcpu-1gb --ssh-keys <SSH-KEY-ID> --wait
<DROPLET-NAME>
with your desired droplet name.<SSH-KEY-ID>
with your SSH key ID. You can find this by running doctl compute ssh-key list
.doctl compute droplet create pirateapp --region syd1 --image ubuntu-22-04-x64 --size s-1vcpu-1gb --ssh-keys 42754072 --wait
It will give you the following output or you can use the below command to retrieve the IP address if you need it.
pirate_app git:(main) doctl compute droplet create pirateapp --region syd1 --image ubuntu-22-04-x64 --size s-1vcpu-1gb --ssh-keys 42754072 --wait
ID Name Public IPv4 Private IPv4 Public IPv6 Memory VCPUs Disk Region Image VPC UUID Status Tags Features Volumes
432279856 pirateapp 170.69.169.169 10.126.0.2 1024 1 25 syd1 Ubuntu 22.04 (LTS) x64 102fec11-b9ca-4d95-9870-9619086e2408 active droplet_agent,private_networking
Retrieve Droplet IP:
doctl compute droplet list
Delete your instance if you’re not ready to use it
doctl compute droplet delete pirateapp -f
ssh -i ~/.ssh/id_rsa root@<your-ip>
ssh -i ~/.ssh/id_rsa root@<your-ip>
sudo apt-get update && sudo apt-get upgrade -y
# Download the Docker installation script
curl -fsSL https://get.docker.com -o install-docker.sh
# Verify the script's content (optional but recommended)
cat install-docker.sh
# Run the script with --dry-run to verify the steps it executes (optional)
sh install-docker.sh --dry-run
# Run the script to install Docker
sudo sh install-docker.sh
sudo systemctl start docker
sudo systemctl enable docker
sudo usermod -aG docker ${USER}
su - ${USER}
# Check Docker
docker --version
docker run hello-world
If you have been following along we have broken our Dockerfile
for production. I will go through and figure this out but for now we will have this section that explains what we need for it to build properly for Vite. Please update your Dockerfile
to the following.
# syntax=docker/dockerfile:1
# Make sure RUBY_VERSION matches the Ruby version in .ruby-version and Gemfile
ARG RUBY_VERSION=3.3.0
FROM registry.docker.com/library/ruby:$RUBY_VERSION-slim AS base
# Rails app lives here
WORKDIR /rails
# Set production environment
ENV RAILS_ENV="production" \
BUNDLE_DEPLOYMENT="1" \
BUNDLE_PATH="/usr/local/bundle" \
BUNDLE_WITHOUT="development"
# Throw-away build stage to reduce size of final image
FROM base AS build
# Install packages needed to build gems and Node.js
RUN apt-get update -qq && \
apt-get install --no-install-recommends -y build-essential git libpq-dev libvips pkg-config curl && \
curl -fsSL https://deb.nodesource.com/setup_20.x | bash - && \
apt-get install --no-install-recommends -y nodejs
# Install application gems
COPY Gemfile Gemfile.lock ./
# Use secret to access GitHub token
RUN --mount=type=bind,target=. \
--mount=type=secret,id=GITHUB_TOKEN \
GITHUB_TOKEN=$(cat /run/secrets/GITHUB_TOKEN) && \
git config --global url."https://${GITHUB_TOKEN}@github.com/".insteadOf "https://github.com/" && \
bundle install && \
rm -rf ~/.bundle/ "${BUNDLE_PATH}"/ruby/*/cache "${BUNDLE_PATH}"/ruby/*/bundler/gems/*/.git && \
bundle exec bootsnap precompile --gemfile
# Install Node.js packages
COPY package.json package-lock.json ./
RUN npm install
# Copy application code
COPY . .
# Run Vite build
RUN npx vite build
# Precompile bootsnap code for faster boot times
RUN bundle exec bootsnap precompile app/ lib/
# Precompiling assets for production without requiring secret RAILS_MASTER_KEY
RUN SECRET_KEY_BASE_DUMMY=1 ./bin/rails assets:precompile
# Final stage for app image
FROM base
# Install packages needed for deployment
RUN apt-get update -qq && \
apt-get install --no-install-recommends -y curl libvips postgresql-client && \
rm -rf /var/lib/apt/lists /var/cache/apt/archives
# Copy built artifacts: gems, application
COPY --from=build /usr/local/bundle /usr/local/bundle
COPY --from=build /rails /rails
# Run and own only the runtime files as a non-root user for security
RUN useradd rails --create-home --shell /bin/bash && \
chown -R rails:rails db log storage tmp
USER rails:rails
# Entrypoint prepares the database.
ENTRYPOINT ["/rails/bin/docker-entrypoint"]
# Start the server by default, this can be overwritten at runtime
EXPOSE 3000
CMD ["./bin/rails", "server"]
Instead of running on the system directly we can run the application using Docker Compose. Create a docker-compose.yml
file in your application directory:
Note: This is on the droplet you will be deploying to.
services:
db:
image: postgres:16
volumes:
- postgres_data:/var/lib/postgresql/data
environment:
POSTGRES_DB: pirate_app_production
POSTGRES_USER: pirate_app
POSTGRES_PASSWORD: ${PIRATE_APP_DATABASE_PASSWORD}
redis:
image: redis:7
web:
build: .
command: bundle exec rails server -b 0.0.0.0
volumes:
- .:/rails
ports:
- "80:3000"
environment:
RAILS_ENV: production
SECRET_KEY_BASE: ${SECRET_KEY_BASE}
DATABASE_URL: postgres://pirate_app:${PIRATE_APP_DATABASE_PASSWORD}@db:5432/pirate_app_production
REDIS_URL: redis://redis:6379/1
depends_on:
- db
- redis
volumes:
postgres_data:
Create a GitHub Actions workflow file (e.g., .github/workflows/deploy.yml
):
name: Deploy
on:
workflow_run:
workflows: ["CI"]
types:
- completed
jobs:
deploy:
runs-on: ubuntu-latest
if: $
steps:
- name: Checkout code
uses: actions/checkout@v4
- name: Set up Docker Buildx
uses: docker/setup-buildx-action@v2
- name: Login to GitHub Container Registry
uses: docker/login-action@v2
with:
registry: ghcr.io
username: $
password: $
- name: Build and push Docker image
run: |
echo "$" | docker login ghcr.io -u $ --password-stdin
GITHUB_TOKEN=$ docker buildx build --secret id=GITHUB_TOKEN -t ghcr.io/loftwah-demo/pirate_app/pirateapp:latest --push .
- name: Deploy to droplet
uses: appleboy/ssh-action@master
with:
host: 170.64.189.40
username: root
key: $
script: |
echo "$" | docker login ghcr.io -u $ --password-stdin
docker compose -f /root/docker-compose.prod.yml --env-file /root/.env down
docker compose -f /root/docker-compose.prod.yml --env-file /root/.env pull
docker compose -f /root/docker-compose.prod.yml --env-file /root/.env up -d
Add the following secrets to your GitHub repository:
GH_PAT
DROPLET_SSH_PRIVATE_KEY
PIRATE_APP_DATABASE_PASSWORD
SECRET_KEY_BASE
GITHUB_TOKEN:
repo
and write:packages
permissions.DIGITALOCEAN_API_TOKEN:
DIGITALOCEAN_SSH_KEY_ID:
doctl compute ssh-key list
.Note: Your application should be deployed but because we deployed the production environment we require a secure connection. You can modify the Rails config in your application if you want to see this in
config/environments/production.rb
where you need to changeconfig.force_ssl = false
. For info: I ended up updating this in my repo because it is only a demo application and who cares right? We can still set up SSL with this set tofalse
.
By following these steps, you can set up a CI/CD pipeline with GitHub Actions and automate the deployment of your Rails application on DigitalOcean using doctl
and GitHub Container Registry. This approach simplifies the deployment process, making it easier to manage infrastructure and deploy updates efficiently. Happy sailing, and may your deployments be swift and smooth!
Benefits of Multi-Stage Builds for Docker Images
Arrr, ye scallywags, gather ‘round and lend an ear! The seas be rough, and our ship must be lean and mean. Multi-stage builds be our secret weapon, a true marvel of Docker wizardry. By breakin’ down our build into stages, we be savin’ space and keepin’ our final image as trim as a corsair’s blade. No more bloatin’ with unnecessary artifacts, aye, just the essentials to sail smooth and fast.
Implementin’ Multi-Stage Builds in Your Dockerfile
To start, ye be needin’ a Dockerfile more cunning than a fox in a henhouse. First, we be usin’ one stage to build our treasures, then another to copy only the finest loot into our final image. Here be an example from the ship’s log:
# syntax=docker/dockerfile:1
# Make sure RUBY_VERSION matches the Ruby version in .ruby-version and Gemfile
ARG RUBY_VERSION=3.3.0
FROM registry.docker.com/library/ruby:$RUBY_VERSION-slim AS base
# Rails app lives here
WORKDIR /rails
# Set production environment
ENV RAILS_ENV="production" \
BUNDLE_DEPLOYMENT="1" \
BUNDLE_PATH="/usr/local/bundle" \
BUNDLE_WITHOUT="development"
# Throw-away build stage to reduce size of final image
FROM base AS build
# Install packages needed to build gems and Node.js
RUN apt-get update -qq && \
apt-get install --no-install-recommends -y build-essential git libpq-dev libvips pkg-config curl && \
curl -fsSL https://deb.nodesource.com/setup_20.x | bash - && \
apt-get install --no-install-recommends -y nodejs
# Install application gems
COPY Gemfile Gemfile.lock ./
# Use secret to access GitHub token
RUN --mount=type=bind,target=. \
--mount=type=secret,id=GITHUB_TOKEN \
GITHUB_TOKEN=$(cat /run/secrets/GITHUB_TOKEN) && \
git config --global url."https://${GITHUB_TOKEN}@github.com/".insteadOf "https://github.com/" && \
bundle install && \
rm -rf ~/.bundle/ "${BUNDLE_PATH}"/ruby/*/cache "${BUNDLE_PATH}"/ruby/*/bundler/gems/*/.git && \
bundle exec bootsnap precompile --gemfile
# Install Node.js packages
COPY package.json package-lock.json ./
RUN npm install
# Copy application code
COPY . .
# Run Vite build
RUN npx vite build
# Precompile bootsnap code for faster boot times
RUN bundle exec bootsnap precompile app/ lib/
# Precompiling assets for production without requiring secret RAILS_MASTER_KEY
RUN SECRET_KEY_BASE_DUMMY=1 ./bin/rails assets:precompile
# Final stage for app image
FROM base
# Install packages needed for deployment
RUN apt-get update -qq && \
apt-get install --no-install-recommends -y curl libvips postgresql-client && \
rm -rf /var/lib/apt/lists /var/cache/apt/archives
# Copy built artifacts: gems, application
COPY --from=build /usr/local/bundle /usr/local/bundle
COPY --from=build /rails /rails
# Run and own only the runtime files as a non-root user for security
RUN useradd rails --create-home --shell /bin/bash && \
chown -R rails:rails db log storage tmp
USER rails:rails
# Entrypoint prepares the database.
ENTRYPOINT ["/rails/bin/docker-entrypoint"]
# Start the server by default, this can be overwritten at runtime
EXPOSE 3000
CMD ["./bin/rails", "server"]
# Build command
GITHUB_TOKEN=<my-token> docker buildx build --secret id=GITHUB_TOKEN -t pirate_app .
# Run command
docker run -e SECRET_KEY_BASE=<my-key> -p 3000:3000 pirate_app
With this strategy, our final image be as swift as a schooner, ready to plunder the seven seas!
Managing Data Persistence with Docker Volumes
Aye, the life of a pirate be full of treasures, and we must keep ‘em safe! Docker volumes be our chests to store precious data. They be independent of the container lifecycle, so our treasures don’t disappear into the briny deep when a container meets Davy Jones. Here’s how ye be creatin’ a volume:
docker volume create my_volume
Mount it in yer container like so:
docker run -v my_volume:/path/in/container my_image
Now, our loot be safe and sound, even if the seas get stormy!
Purging Data and Considerations
But beware, ye don’t want to be caught with too much ballast! When the time comes to purge old data, make sure ye know what ye be doin’. Deleting a volume be permanent, like sendin’ it to the depths of the ocean. To remove a volume:
docker volume rm my_volume
Think twice before ye hit that command, or ye might be losin’ vital booty.
Configurin’ Docker Networks for Inter-Container Communication
To navigate the vast waters of inter-container communication, Docker networks be our charts and compass. Ye can set up a bridge network for yer containers to talk like old sea dogs:
docker network create my_network
Run yer containers on this network:
docker run --network my_network --name container_one my_image
docker run --network my_network --name container_two my_image
Now, container_one
and container_two
be chattin’ like old mates in a tavern, sharin’ secrets and plans for their next big raid.
So there ye have it, me hearties! Master these advanced Docker techniques, and ye’ll be the scourge of the seven seas, feared by all and master of your digital domain! Arrr!
Tools and Techniques for Monitoring a Rails Application
Ahoy, ye salty dogs! Keepin’ a sharp eye on yer Rails application be as crucial as watchin’ the horizon for enemy ships. Here be a list of fine tools to help ye monitor the health and performance of yer app:
Settin’ up these tools be a task for a seasoned quartermaster. Configure ‘em properly to ensure they be reportin’ accurate and useful information.
Logging at the Application and System Level
Loggin’ be the ship’s log of yer application. At the application level, log errors, warnings, and key events to understand the state of yer app. System-level logging captures events at the OS level, such as resource usage and network activity. Together, they paint a full picture of yer ship’s health.
# Rails example for logging
Rails.logger.info "Shiver me timbers! This be a log message."
Strategies for Scaling Your Application Using Docker and Cloud Services
Scalin’ yer application be like addin’ more sails to catch the wind. Docker and cloud services be the wind in those sails, helpin’ ye handle more traffic without capsizin’. Here be some strategies:
Here be an example of a docker-compose.yml
file that scales yer Rails app with PostgreSQL and Redis:
services:
db:
image: postgres:16
volumes:
- postgres_data:/var/lib/postgresql/data
environment:
POSTGRES_DB: pirate_app_production
POSTGRES_USER: pirate_app
POSTGRES_PASSWORD: ${PIRATE_APP_DATABASE_PASSWORD}
ports:
- "5432:5432"
redis:
image: redis:7
ports:
- "6379:6379"
web:
build: .
command: bundle exec rails server -b 0.0.0.0
volumes:
- .:/rails
ports:
- "3000:3000"
environment:
RAILS_ENV: production
SECRET_KEY_BASE: ${SECRET_KEY_BASE}
DATABASE_URL: postgres://pirate_app:${PIRATE_APP_DATABASE_PASSWORD}@db:5432/pirate_app_production
REDIS_URL: redis://redis:6379/1
depends_on:
- db
- redis
volumes:
postgres_data:
Auto-Scaling and Load Balancin’ Considerations
Auto-scaling keeps yer ship ready for any storm, addin’ or removin’ resources based on demand. Cloud providers like AWS, Azure, and Google Cloud offer auto-scaling services. Configure yer auto-scaling policies to match yer needs, considerin’ metrics like CPU usage, memory, and request count.
Load balancers be the helmsmen, directin’ traffic to ensure no single container be overwhelmed. Configure health checks to ensure only healthy containers receive traffic.
Configurin’ Instance Sizes, CPU Specs, Storage, etc.
Choose the right instance sizes for yer needs. Consider CPU, memory, and storage requirements:
With these techniques, ye’ll be ready to scale yer application like a true captain of the digital seas, conquerin’ new lands and servin’ more users without fear! Arrr!
Common Security Vulnerabilities and How to Mitigate Them
In the treacherous waters ye must guard yer Docker containers against scallywags and marauders. Here be the most common vulnerabilities and how ye can fortify yer defenses:
Outdated Images: Keep yer base images up to date. Use trusted sources and scan for vulnerabilities with tools like Anchore or Trivy.
docker scan my_image
Unnecessary Privileges: Run containers with the least privilege necessary. Avoid root user; create a dedicated user instead.
FROM registry.docker.com/library/ruby:3.3.0-slim
RUN useradd -m appuser
USER appuser
Unexposed Ports: Only expose the ports ye need. Unexposed ports be like open portholes for enemies.
ports:
- "3000:3000"
Secrets in Images: Never hardcode secrets in yer images. Use environment variables or secrets management tools.
Best Practices for Handling Sensitive Information in Docker and CI/CD Pipelines
In the digital age of 2024, handling secrets be akin to guarding a treasure map. Here be the best practices to ensure yer secrets stay secret:
Environment Variables: Store sensitive data in environment variables. Use .env
files and Docker secrets for better security.
docker run -e SECRET_KEY_BASE=${SECRET_KEY_BASE} my_app
Secrets Management Tools: Use tools like HashiCorp Vault, AWS Secrets Manager, or Azure Key Vault to manage secrets securely.
secrets:
secret_key_base:
file: ./secrets/secret_key_base
CI/CD Pipelines: Ensure that yer CI/CD pipelines are secure. Use built-in secrets management in GitHub Actions, GitLab CI, or Jenkins.
jobs:
deploy:
secrets:
SECRET_KEY_BASE: $
Context-Specific Security Considerations
Security be not one-size-fits-all. Consider the context in which ye operate:
Public vs. Private Repositories: For public repositories, never store sensitive data in code. For private repositories, still follow best practices to avoid leaks.
Compliance Requirements: Ensure ye meet industry-specific compliance, such as GDPR for personal data or PCI DSS for payment information.
Network Security: Configure yer Docker networks to limit exposure. Use firewalls and VPNs for additional layers of security.
networks:
default:
external:
name: my_private_network
Monitoring and Auditing: Regularly monitor and audit yer containers and systems. Use tools like Falco for runtime security monitoring.
With these best practices, yer Docker containers and sensitive data will be guarded like the finest treasures in the pirate’s hold, safe from the hands of ne’er-do-wells and rival captains. Arrr!
Troubleshooting Common Problems in Dockerized Rails Applications
Even the finest ships encounter rough seas. Here be some common issues ye might face with Dockerized Rails applications, along with solutions to keep yer vessel on course:
Container Fails to Start: Check yer logs first and foremost. Use docker logs <container_id>
to see what be ailin’ yer container.
docker logs pirate_app
Database Connection Errors: Ensure that yer environment variables be correctly set. Verify that the database service be up and accessible.
environment:
DATABASE_URL: postgres://pirate_app:${PIRATE_APP_DATABASE_PASSWORD}@db:5432/pirate_app_production
Missing Gems or Node Modules: Double-check yer Dockerfile
and ensure that dependencies be properly installed.
COPY Gemfile Gemfile.lock ./
RUN bundle install
COPY package.json package-lock.json ./
RUN npm install
Slow Performance: Examine resource usage. Ensure containers have enough CPU and memory. Use tools like Docker stats to monitor performance.
docker stats
Tools and Methods for Effective Debugging in a Docker Environment
Debugging be a critical skill for any pirate captain. Here be tools and techniques to help ye navigate troubled waters:
Interactive Shell: Enter yer running container with an interactive shell to inspect and debug.
docker exec -it pirate_app /bin/bash
Rails Console: Use the Rails console within the container to test and debug application code.
docker exec -it pirate_app bundle exec rails console
Binding.pry: Use the pry
gem for interactive debugging. Insert binding.pry
in yer code and restart the container.
gem 'pry'
# In your code
binding.pry
Logs and Monitoring: Continuously monitor logs using tools like Logspout or integrated logging services in AWS, Azure, or GCP.
docker logs -f pirate_app
Debugger Tools: Leverage debuggers like Byebug or Pry-Byebug for more advanced debugging capabilities.
gem 'byebug'
# In your code
debugger
Health Checks: Implement health checks in yer Docker Compose file to automatically restart unhealthy containers.
services:
web:
healthcheck:
test: ["CMD", "curl", "-f", "http://localhost:3000"]
interval: 1m30s
timeout: 10s
retries: 3
Network Debugging: Use tools like Wireshark or tcpdump to capture and analyze network traffic within yer Docker network.
docker run --rm -it --network container:pirate_app nicolaka/netshoot
With these techniques and tools, ye’ll be well-equipped to troubleshoot and debug yer Dockerized Rails applications, ensuring smooth sailin’ on the high seas of development. Arrr!
Congratulations, mateys! Ye’ve sailed through the vast and turbulent seas of Docker and Ruby on Rails, learnin’ the ins and outs of modern application deployment and development. Here be a summary of the key takeaways from this adventure:
Setting Sail with Ruby on Rails: Ye set up a Rails application, configured it with PostgreSQL and Tailwind CSS, and learned the project structure.
Docker – Yer Ship for the Journey: We explored Docker, wrote Dockerfiles, and ran our Rails app in containers, understandin’ the importance of containerization.
Docker Compose – Coordinatin’ Yer Fleet: Ye configured Docker Compose to manage multiple services, makin’ development and deployment more efficient.
Guardin’ Yer Treasure – Private Dependencies: Ye integrated private Ruby gems and npm packages into yer Rails app, ensuring secure and modular code.
Secure Authentication with SSH and HTTPS: Ye set up SSH keys and GitHub Personal Access Tokens (PATs) for secure access to private repositories.
Automatin’ Yer Deployment – CI/CD: Ye established a CI/CD pipeline with GitHub Actions, deployin’ yer Rails application to DigitalOcean using doctl
.
Advanced Docker Techniques: Ye learned about multi-stage builds, Docker volumes, and networks, ensuring yer containers are efficient and secure.
Monitoring and Scaling Yer Application: Ye set up monitoring tools and strategies for scaling yer application using Docker and cloud services.
Security Best Practices: Ye fortified yer Docker containers against vulnerabilities and managed secrets securely in yer CI/CD pipelines.
Troubleshootin’ and Debuggin’: Ye tackled common issues in Dockerized Rails applications and mastered debugging techniques to keep yer app shipshape.
The journey doesn’t end here, mateys! The seas of technology are always changin’, and it’s important to keep learnin’ and adaptin’. Here be some resources to help ye stay updated and further yer knowledge:
Official Documentation:
Online Courses and Tutorials:
Community and Forums:
Books and Publications:
Conferences and Meetups:
Practice and Projects:
With this knowledge, ye’re equipped to conquer the digital seas, buildin’ robust and scalable applications with Docker and Ruby on Rails. Keep explorin’, innovatin’, and sailin’ towards new horizons. May yer code be clean, yer deployments swift, and yer adventures grand!
Fair winds and following seas, mateys! Arrr!
# syntax=docker/dockerfile:1
ARG RUBY_VERSION=3.3.0
FROM registry.docker.com/library/ruby:$RUBY_VERSION-slim AS base
WORKDIR /rails
ENV RAILS_ENV="production" \
BUNDLE_DEPLOYMENT="1" \
BUNDLE_PATH="/usr/local/bundle" \
BUNDLE_WITHOUT="development"
FROM base AS build
RUN apt-get update -qq && \
apt-get install --no-install-recommends -y build-essential git libpq-dev libvips pkg-config curl && \
curl -fsSL https://deb.nodesource.com/setup_20.x | bash - && \
apt-get install --no-install-recommends -y nodejs
COPY Gemfile Gemfile.lock ./
RUN --mount=type=bind,target=. \
--mount=type=secret,id=GITHUB_TOKEN \
GITHUB_TOKEN=$(cat /run/secrets/GITHUB_TOKEN) && \
git config --global url."https://${GITHUB_TOKEN}@github.com/".insteadOf "https://github.com/" && \
bundle install && \
rm -rf ~/.bundle/ "${BUNDLE_PATH}"/ruby/*/cache "${BUNDLE_PATH}"/ruby/*/bundler/gems/*/.git && \
bundle exec bootsnap precompile --gemfile
COPY package.json package-lock.json ./
RUN npm install
COPY . .
RUN npx vite build
RUN bundle exec bootsnap precompile app/ lib/
RUN SECRET_KEY_BASE_DUMMY=1 ./bin/rails assets:precompile
FROM base
RUN apt-get update -qq && \
apt-get install --no-install-recommends -y curl libvips postgresql-client && \
rm -rf /var/lib/apt/lists /var/cache/apt/archives
COPY --from=build /usr/local/bundle /usr/local/bundle
COPY --from=build /rails /rails
RUN useradd rails --create-home --shell /bin/bash && \
chown -R rails:rails db log storage tmp
USER rails:rails
ENTRYPOINT ["/rails/bin/docker-entrypoint"]
EXPOSE 3000
CMD ["./bin/rails", "server"]
services:
db:
image: postgres:16
volumes:
- postgres_data:/var/lib/postgresql/data
environment:
POSTGRES_DB: pirate_app_production
POSTGRES_USER: pirate_app
POSTGRES_PASSWORD: ${PIRATE_APP_DATABASE_PASSWORD}
ports:
- "5432:5432"
redis:
image: redis:7
ports:
- "6379:6379"
web:
build: .
command: bundle exec rails server -b 0.0.0.0
volumes:
- .:/rails
ports:
- "3000:3000"
environment:
RAILS_ENV: production
SECRET_KEY_BASE: ${SECRET_KEY_BASE}
DATABASE_URL: postgres://pirate_app:${PIRATE_APP_DATABASE_PASSWORD}@db:5432/pirate_app_production
REDIS_URL: redis://redis:6379/1
depends_on:
- db
- redis
volumes:
postgres_data:
I haven’t thought of the following or where to put them yet.
Stress (Linux)
A simple command-line tool to impose load on the system’s CPU, memory, and disk I/O. Application: Useful for stress testing the server infrastructure to observe system behavior under high load.
Loadster (Service)
A cloud-based load testing service that simulates user traffic from multiple locations. Application: Effective for testing the performance and scalability of web applications under real-world usage patterns.
k6 (Grafana Labs)
A modern load testing tool using JavaScript to write test scripts, integrated with Grafana for monitoring. Application: Ideal for continuous performance testing and monitoring, with the ability to integrate into CI/CD pipelines for automated testing.
I had to change the application JavaScript to import the stylesheet.
// Configure your import map in config/importmap.rb. Read more: https://github.com/rails/importmap-rails
import '../stylesheets/application.css'
// To see this message, add the following to the `<head>` section in your
// views/layouts/application.html.erb
//
// <%= vite_client_tag %>
// <%= vite_javascript_tag 'application' %>
console.log('Vite ⚡️ Rails')
// If using a TypeScript entrypoint file:
// <%= vite_typescript_tag 'application' %>
//
// If you want to use .jsx or .tsx, add the extension:
// <%= vite_javascript_tag 'application.jsx' %>
console.log('Visit the guide for more information: ', 'https://vite-ruby.netlify.app/guide/rails')
// Example: Load Rails libraries in Vite.
//
// import * as Turbo from '@hotwired/turbo'
// Turbo.start()
//
// import ActiveStorage from '@rails/activestorage'
// ActiveStorage.start()
//
// // Import all channels.
// const channels = import.meta.globEager('./**/*_channel.js')
// Example: Import a stylesheet in app/frontend/index.css
// import '~/index.css'
I commented out everything in app/javascript/application.js
.
// Configure your import map in config/importmap.rb. Read more: https://github.com/rails/importmap-rails
// import "@hotwired/turbo-rails"
// import "controllers"
// import './stylesheets/application.css'
Add PostCSS configuration:
// postcss.config.js
module.exports = {
plugins: {
tailwindcss: {},
autoprefixer: {},
},
};
Add Vite configuration with PostCSS plugins:
// vite.config.ts
import { defineConfig } from 'vite'
import RubyPlugin from 'vite-plugin-ruby'
import tailwindcss from 'tailwindcss'
import autoprefixer from 'autoprefixer'
export default defineConfig({
plugins: [
RubyPlugin(),
],
css: {
postcss: {
plugins: [
tailwindcss,
autoprefixer,
],
},
},
assetsInclude: ['**/*.png', '**/*.jpg', '**/*.jpeg', '**/*.gif', '**/*.svg'],
})
In development, I set the following configurations:
# config/environments/development.rb
config.assets.quiet = false
config.assets.debug = true
The following stylesheet was missing and added:
/* pirate_app/app/javascript/stylesheets/application.css */
@import "tailwindcss/base";
@import "tailwindcss/components";
@import "tailwindcss/utilities";
Ensure your project structure under app/javascript
looks like this:
app/javascript
├── images
│ ├── logo.png
│ ├── favicon.png
│ └── social-banner.png
├── entrypoints
│ ├── application.js
│ ├── application.css
│ └── main.js
├── styles
│ └── main.css
└── index.html
Place your images (e.g., logo, favicon, social banner) in the app/javascript/images
directory.
Ensure your vite.config.ts
is set up correctly:
// vite.config.ts
import { defineConfig } from 'vite'
import RubyPlugin from 'vite-plugin-ruby'
export default defineConfig({
plugins: [
RubyPlugin(),
],
assetsInclude: ['**/*.png', '**/*.jpg', '**/*.jpeg', '**/*.gif', '**/*.svg'],
})
Update your application layout to include Vite tags and Open Graph meta tags.
<!DOCTYPE html>
<html>
<head>
<title>PirateApp</title>
<%= csrf_meta_tags %>
<%= csp_meta_tag %>
<%= stylesheet_link_tag "application", "data-turbo-track": "reload" %>
<%= javascript_include_tag "application", "data-turbo-track": "reload", defer: true %>
<%= vite_client_tag %>
<%= vite_javascript_tag 'application' %>
<!-- Open Graph meta tags -->
<meta property="og:title" content="Linux for Pirates! 2 - Ruby on Whales" />
<meta property="og:description" content="Embark on a Ruby adventure with Linux for Pirates! 2 - Ruby on Whales. Learn Ruby and conquer the seas!" />
<meta property="og:image" content="<%= vite_asset_url 'images/pirate-adventure.png' %>" />
<meta property="og:url" content="<%= request.original_url %>" />
<meta name="twitter:card" content="summary_large_image" />
</head>
<body class="bg-blue-900 text-white">
<header class="bg-gray-800 p-4">
<div class="container mx-auto flex justify-between items-center">
<h1 class="text-2xl font-bold">PirateApp</h1>
<nav>
<ul class="flex space-x-4">
<li><a href="/" class="hover:text-yellow-500">Home</a></li>
</ul>
</nav>
</div>
</header>
<%= yield %>
<footer class="bg-gray-800 p-4 mt-10">
<div class="container mx-auto text-center">
<p>© 2024 PirateApp. All rights reserved.</p>
</div>
</footer>
</body>
</html>
Update your view to include image tags and debug information.
<!DOCTYPE html>
<html>
<head>
<title>PirateApp</title>
</head>
<body>
<h1>Home</h1>
<p>Linux for Pirates! 2 - Ruby on Whales</p>
<p>Embark on a Ruby adventure with Linux for Pirates! 2 - Ruby on Whales. Learn Ruby and conquer the seas!</p>
<!-- Print the asset path for debugging -->
<p>Image Path: <%= vite_asset_path('images/book-cover.jpg') %></p>
<p>Image Path: <%= vite_asset_path('images/pirate-adventure.png') %></p>
<!-- Display the images -->
<%= image_tag vite_asset_path('images/book-cover.jpg') %>
<%= image_tag vite_asset_path('images/pirate-adventure.png') %>
<footer>
<p>Pirate Adventure</p>
<a href="#">Get Started</a>
<p>© 2024 PirateApp. All rights reserved.</p>
</footer>
</body>
</html>
Run your Rails server and test the page locally to ensure everything is working as expected. When you’re ready, deploy your application.
rails server
This guide provides a comprehensive overview of upgrading your landing page to promote “Linux for Pirates! 2 - Ruby on Whales” using Vite in a Rails application.
Note: There is still a warning in Tailwind but I can’t figure it out yet.
The Rails plugin for Vite generates a vite.config.ts
that has been deprecated. Instead of translating the configuration file, updating the package.json
can resolve the deprecation warning.
{
"name": "pirate_app",
"version": "1.0.0",
"description": "This README would normally document whatever steps are necessary to get the application up and running.",
"main": "index.js",
"directories": {
"lib": "lib",
"test": "test"
},
"scripts": {
"test": "echo \"Error: no test specified\" && exit 1"
},
"keywords": [],
"author": "",
"license": "ISC",
"dependencies": {
"autoprefixer": "^10.4.19",
"my-private-npm-package": "git+https://github.com/loftwah-demo/my-private-npm-package.git",
"tailwindcss": "^3.4.4"
},
"devDependencies": {
"vite": "^5.3.3",
"vite-plugin-ruby": "^5.0.0"
}
}
To resolve the deprecation warning, add "type": "module"
to your package.json
.
{
"name": "pirate_app",
"version": "1.0.0",
"description": "This README would normally document whatever steps are necessary to get the application up and running.",
"main": "index.js",
"type": "module",
"directories": {
"lib": "lib",
"test": "test"
},
"scripts": {
"test": "echo \"Error: no test specified\" && exit 1"
},
"keywords": [],
"author": "",
"license": "ISC",
"dependencies": {
"autoprefixer": "^10.4.19",
"my-private-npm-package": "git+https://github.com/loftwah-demo/my-private-npm-package.git",
"tailwindcss": "^3.4.4"
},
"devDependencies": {
"vite": "^5.3.3",
"vite-plugin-ruby": "^5.0.0"
}
}
Enabling "type": "module"
in package.json
resolves the CJS deprecation warning.
The error Errno::EACCES
indicates that there is a permissions issue when trying to access a file or directory. In this case, it is related to the cache directory used by Sprockets. The specific file it is trying to access is /home/loftwah/gits/dockerrails/pirate_app/tmp/cache/assets/sprockets/v4.0.0/2K/2Kqqs5CDZKeqQ8Zi3OcRThACYBsE09CB_YbQaG96080.cache
.
To resolve this issue, you need to ensure that the user running the Rails server has the appropriate permissions to read and write to this directory. Here are the steps you can take to fix this:
Check and Update Permissions:
Ensure that the tmp
directory and its subdirectories have the correct permissions. You can use the chmod
command to set the correct permissions.
sudo chmod -R 755 /home/loftwah/gits/dockerrails/pirate_app/tmp
This sets the permissions to read, write, and execute for the owner, and read and execute for group and others.
Change Ownership:
Ensure that the correct user owns the directory and its contents. Replace username
with the appropriate user (e.g., your current user or the user running the Rails server).
sudo chown -R username:username /home/loftwah/gits/dockerrails/pirate_app/tmp
Clear the Cache:
If the issue persists, you can try clearing the cache to ensure there are no corrupted files causing the issue.
bundle exec rails tmp:cache:clear
After applying these changes, restart your Rails server and check if the issue is resolved.
This error is caused by a permissions issue with the cache directory used by Sprockets. By updating the permissions and ensuring the correct ownership, you can resolve the issue and allow your Rails server to access the necessary files.