Docker does for DevOps what Rails did for web development — it gives you a new set of superpowers. Gone are "works on my machine" woes and lengthy setup tasks, replaced instead by a simple, consistent, Docker-based development environment that will have your team up and running in seconds. Gain hands-on, real-world experience with a tool that's rapidly becoming fundamental to software development. Go from zero all the way to production as Docker transforms the massive leap of deploying your app in the cloud into a baby step.
Docker makes life as a Ruby and Rails developer easier. It helps build, ship, and run your applications, solving major problems you face every day. It allows you to run applications at scale, adding new resources as needed. Docker provides a reliable, consistent environment that's guaranteed to work the same everywhere.
Docker lets you do all things DevOps without needing a PhD in infrastructure and operations. Want to spin up a cluster to run your app? No problem. Scale it up or down at will? You bet. Start by running a Ruby script without having Ruby installed on the local machine. Then Dockerize a Rails application and run it using containers, including creating your own custom Docker images tailored for running Rails apps. Describe your app declaratively using Docker Compose, specifying the software dependencies along with everything needed to run the application. Then set up continuous integration, as well as your deployment pipeline and infrastructure. Along the way, find out the best practices for using Docker in development and production environments.
This book gives you a solid foundation on using Docker and fitting it into your development workflow and deployment process.
What You Need:
All you need is a Windows, Mac OS X or Linux machine to do development on. This book guides you through the process of installing Docker. Some basic familiarity with Linux/Unix is recommended even if you're using a Windows machine.
Author(s): Rob Isenberg
Edition: 1
Publisher: Pragmatic Bookshelf
Year: 2019
Language: English
Commentary: True PDF
Pages: 240
City: Raleigh, NC
Tags: DevOps; JavaScript; Ruby; PostgreSQL; Docker; Deployment; Redis; Kubernetes; Testing; Container Orchestration; Docker Swarm; Docker Compose; Rails; Package Management; RSpec
Cover
Table of Contents
Acknowledgements
Introduction
What Is Docker?
Why Use Docker?
Who Should Read This Book?
What’s in This Book?
How to Read This Book
Which Operating Systems Are Supported?
Online Resources
Part I—Development
1. A Brave New World
Installing Docker
Verifying Your Install
Before We Begin
Running a Ruby Script Without Ruby Installed
Generating a New Rails App Without Ruby Installed
Quick Recap
2. Running a Rails App in a Container
How Do We Run Our Rails App?
Defining Our First Custom Image
Building Our Image
Running a Rails Server with Our Image
Reaching the App: Publishing Ports
Binding the Rails Server to IP Addresses
Quick Recap
3. Fine-Tuning Our Rails Image
Naming and Versioning Our Image
A Default Command
Ignoring Unnecessary Files
The Image Build Cache
Caching Issue 1: Updating Packages
Caching Issue 2: Unnecessary Gem Installs
The Finishing Touch
Quick Recap
4. Describing Our App Declaratively with Docker Compose
Getting Started with Compose
Launching Our App
Mounting a Local Volume
Starting and Stopping Services
Other Common Tasks
Quick Recap
5. Beyond the App: Adding Redis
Starting a Redis Server
Manually Connecting to the Redis Server
How Containers Can Talk to Each Other
Our Rails App Talking to Redis
Starting the Entire App with Docker Compose
Quick Recap
6. Adding a Database: Postgres
Starting a Postgres Server
Connecting to Postgres from a Separate Container
Connecting Our Rails App to Postgres
Using the Database in Practice
Decoupling Data from the Container
Quick Recap
7. Playing Nice with JavaScript
The JavaScript Front-End Options
Rails JavaScript Front End with Webpacker
Compiling Assets with Webpacker
A Hello World React App
Quick Recap
8. Testing in a Dockerized Environment
Setting Up RSpec
Our First Test
Setting Up Rails System Tests
Running Tests That Rely on JavaScript
Debugging
Quick Recap
9. Advanced Gem Management
The Downside to Our Existing Approach
Using a Gem Cache Volume
Quick Recap
10. Some Minor Irritations
Rails tmp/pids/server.pid Not Cleaned Up
Compose Intermittently Aborts with Ctrl-C
Quick Recap
Closing Thoughts on Docker in Development
Part II—Toward Production
11. The Production Landscape
The “Ops” in DevOps
Container Orchestration
A Tale of Two Orchestrators: Swarm and Kubernetes
IaaS vs. CaaS
Provisioning Your Infrastructure
CaaS Platforms
Serverless for Containers
How to Decide What’s Right for Me?
Quick Recap
12. Preparing for Production
Configuring a Production Environment
A Production Image: Precompiling Assets
Sharing Images
Quick Recap
13. A Production-Like Playground
Creating Machines
Introducing Docker Swarm
Our First (Single Node) Swarm
Describing Our App to Swarm
Migrating the Database
Deploying Our App on a Swarm
Tasks and Swarm’s Scaling Model
Scaling Up the Service
Quick Recap
14. Deploying to the Cloud
Creating a DigitalOcean Cluster
Deploying to Our DigitalOcean Swarm
Visualizing Containers
Scale Up the Web Service
Deploying to AWS Instead of DigitalOcean
Quick Recap
15. Closing Thoughts and Next Steps
What Should I Learn About Next?
A1. Platform Differences
File Ownership and Permissions
A2. Finding Images to Use
Using Docker Hub
Using the Docker CLI
Index
