Docker-Rails

Simple Rails 5.2 application to demonstrate using Docker for production deployment. The application is a very simple kind of CMS (content management system) allowing to manage posts. Beside the boring CRUD functionality it has some non-default features.

Features

Auto refresh via ActionCable: If a displayed post gets changed by another user/instance, it refreshes automatically using the publish/subscribe pattern
Full text search via Elasticsearch and the Searchkick gem to find post content (with suggestions)
Autocompletion with corejs-typeahead
PDF export with wkhtmltopdf and the WickedPDF gem
Editing HTML content with the WYSIWYG JavaScript editor Trix
Uploading images directly to S3 with the Shrine gem and jQuery-File-Upload
Display images as Gallery with the React Grid Gallery
Background jobs with ActiveJob and the Sidekiq gem (to handle full text indexing, image processing and ActionCable broadcasting)
Cron scheduling with Sidekiq-Cron to handle daily data updates from Wikipedia
Permalinks using the FriendlyId gem
Infinitive scrolling (using the Kaminari gem and some JavaScript)
User authentication with the Clearance gem
Sending HTML e-mails with Premailer and the Really Simple Responsive HTML Email Template
User visit and click tracking with Ahoy gem
Admin dashboards with Blazer gem
Controller specific JavaScript embedded into the asset pipeline
Bundle JavaScript libraries with Yarn

Why?

This repo demonstrates my way of building Rails applications. The techniques used to build the app should not be considered as "best practice", maybe there are better ways to build. Any feedback would be appreciated.

Multi container architecture

The application is divided into 7 different containers:

app: Main part. It contains the Rails code to handle web requests (with the help of Nginx and the Puma gem). See the Dockerfile for details. The image is based on ledermann/base, which in turn is based on the official Ruby image and just adds Nginx, Node.js and Yarn.
worker: Background processing. It contains the same Rails code, but only runs Sidekiq
db: PostgreSQL database
elasticsearch: Full text search engine
memcached: Memory caching system (used from within the app via the Dalli gem)
redis: In-memory key/value store (used by Sidekiq and ActionCable)
backup: Regularly backups the database as a dump via CRON to an Amazon S3 bucket

For running tests using RSpec, there are two additional containers:

test: Application code prepared for running tests
selenium: Standalone Chrome for executing system tests containing JavaScript

Check it out!

To start up the application in your Docker environment:

git clone https://github.com/ledermann/docker-rails.git
cd docker-rails
cp .env.example .env
docker-compose up --build

Wait some minutes while the database will be prepared. Then, navigate your browser to http://[DOCKER_HOST]:[DOCKER_PORT].

Username: admin@example.org
Password: secret

Enjoy!

Deployment

On every push, the test suite (including RuboCop checks) is run in public on Travis CI and in private on Gitlab CI.

On every push, a new Docker image is built on Docker Hub. Via its auto-deploy feature it can be deployed to your own cloud server.

On every start of the app container, the database will be migrated (or, if not exists, created with some seeds).

If you are already a Docker Cloud user, you can deploy the whole stack with one click:

Domain setup and SSL encryption with Let's Encrypt

The app container is ready to host with nginx proxy and letsencrypt-nginx-proxy-companion. See docker-cloud.yml for example setup.

zenbakiak / docker-rails