Public | Automated Build

Last pushed: 3 hours ago
Short Description
Simple Rails application to demonstrate using Docker, Docker Hub, Docker Cloud and CI
Full Description


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.



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 (by using the Puma gem). See the Dockerfile for details. The image is based on the Alpine variant of the official Ruby image and uses multi-stage building to get a small image.
  • 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
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].

Sign in to the admin account:



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.

Docker Pull Command
Source Repository