Sample application for Docker/Kubernetes/Helm with Rails

Minimal sample application to demonstrate Rails application development with Docker, Kubernetes and Helm.

See blog for details.

Start preview mode with Docker Compose

Prerequisites

Docker, Docker Compose

$ git clone https://github.com/kwhrtsk/rails-k8s-demoapp.git
$ cd rails-k8s-demoapp

# Start mysql and redis container, and build rails app image and start.
$ docker-compose -f docker-compose-preview.yml up -d

# Open top page in your browser
$ open http://localhost:3000/

# Stop all containers and cleanup volumes
$ docker-compose -f docker-compose-preview.yml down

Start local server processes with MySQL and Redis on Docker Compose

Prerequisites

Docker, Docker Compose
Ruby 2.5.1
Node.js 6.0.0+
Yarn 0.25.2+
foreman

$ git clone https://github.com/kwhrtsk/rails-k8s-demoapp.git
$ cd rails-k8s-demoapp

# Start mysql and redis container
$ docker-compose up -d

# Install rubygems
$ bundle install
$ gem install foreman

# Install npm
$ yarn install

# Initialize database
$ ./bin/rails db:setup

# Start puma, sidekiq and webpack-dev-server
$ foreman start -f Procfile

# In another terminal, open top page in your browser.
$ open http://localhost:3000/

Kubernetes

Tested with:

Name	Version
minikube	0.27.0 (k8s 1.10.0)
kubectl	1.10.2
helm	2.9.1
hyperkit	v0.20171204-60-g0e5b6b
stern	1.6.0

Deploy to Kubernetes cluster with plain YAML manifest files

Example manifests to deploy to minikube instance.

step1
- Use only these API Object: Deployment, Service, ConfigMap, Secret
step2
- Add Job from step1's constitution to execute rails db:setup.
- Supports multiple puma containers.
step3
- Add PersistentVolumeClaim from step2's constitution to persistent data of mysql and redis.
step4
- Add Ingress from step3's constitution to expose application with custom TLS certificate and fixed URL.

Deploy to Kubernetes cluster with Helm Chart