Kubernetes + Rails (NGINX & Unicorn) on GCE

db-service.yaml

apiVersion: v1
kind: Service
metadata:
  name: db
  labels:
    name: db
spec:
  ports:
  - port: 5432
  selector:
    run: db

docker-compose.yml

version: '2'
services:
  web:
    restart: always
    dns:
      - 8.8.8.8
    build:
      context: ./web
    environment:
      RAILS_ENV: production
      WEB_DATABASE_HOST: db
      SECRET_KEY_BASE: a964ebdd62805aeff7659781ae0e017e94b9fb8a90a8187dd01f68fefa3791cd1d72ea36f469bc3ad3da1efa36981147afdffe2461afac518ee2a672fb201948
      WEB_DATABASE_PASSWORD: postgres
    expose:
      - "8080"
    volumes:
      - ./web:/my_project
    links:
      - db
  nginx:
    build: ./nginx
    links:
     - web
    #  - api
    ports:
     - "80:80"
    expose:
     - "80"
    volumes:
      - "/var/run/docker.sock:/tmp/docker.sock"
    volumes_from:
      - web
  db:
    image: postgres:latest
    environment:
      POSTGRES_USER: "postgres"
      POSTGRES_PASSWORD: "postgres"
    ports:
      - "5432:5432"

Dockerfile-Nginx

# Set nginx base image
FROM nginx

# Copy custom configuration file from the current directory
COPY nginx.conf /etc/nginx/nginx.conf

Dockerfile-Rail

FROM foxio/rails

RUN apt-get update -qq && apt-get install -y build-essential libpq-dev nodejs npm nodejs-legacy
RUN mkdir /my_project
WORKDIR /my_project

ADD Gemfile /my_project/Gemfile
ADD Gemfile.lock /my_project/Gemfile.lock
RUN bundle install
ADD . /my_project

RUN rake bower:install

RUN apt-get clean && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*

VOLUME ["/tmp"]

RUN chmod +x /my_project/init.sh
RUN chmod +x /my_project/kubernetes-post-start.sh

CMD ["sh", "/my_project/init.sh"]

ENTRYPOINT bundle exec unicorn -c config/unicorn.rb

init.sh

#!/bin/bash

RAILS_ENV=$RAILS_ENV bundle exec rake assets:precompile

kubernetes-post-start.sh

#!/bin/bash

RAILS_ENV=$RAILS_ENV bundle exec rake db:create
RAILS_ENV=$RAILS_ENV bundle exec rake db:migrate
cp -a /my_project/public/. /assets

nginx.conf

worker_processes 4;

events { worker_connections 1024; }

http {

	upstream unicorn {
	      least_conn;
	      #server web:8080 weight=10 max_fails=3 fail_timeout=30s;
				server unix:/tmp/unicorn.sock fail_timeout=0;
	}

	server {
	      listen 80;

				root /my_project/public;

				# serve static (compiled) assets directly if they exist (for rails production)
				location ~ ^/(assets|images|javascripts|stylesheets|swfs|system)/ {
					include /etc/nginx/mime.types;
					try_files $uri @unicorn;

					access_log off;
					gzip_static on; # to serve pre-gzipped version

					expires max;
					add_header Cache-Control public;

					# Some browsers still send conditional-GET requests if there's a
					# Last-Modified header or an ETag header even if they haven't
					# reached the expiry date sent in the Expires header.
					add_header Last-Modified "";
					add_header ETag "";
					break;
				}

				# send non-static file requests to the app server
			  location / {
			    try_files $uri @unicorn;
			  }

	      location @unicorn {
					#proxy_set_header  X-Real-IP  $remote_addr;
					#proxy_set_header  X-Forwarded-For $proxy_add_x_forwarded_for;
					#proxy_set_header Host $http_host;
					#proxy_redirect off;
					#proxy_pass http://unicorn;
					proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
			    proxy_set_header Host $http_host;
			    proxy_redirect off;

					# If you don't find the filename in the static files
			    # Then request it from the unicorn server
			    if (!-f $request_filename) {
			      proxy_pass http://unicorn;
			      break;
			    }
	      }

				error_page 500 502 503 504 /500.html;
			  location = /500.html {
			    root /my_project/public;
			  }
	}
}

unicorn.rb

worker_processes Integer(ENV['WEB_CONCURRENCY'] || 5)
timeout 60
preload_app true

before_fork do |server, worker|
  Signal.trap 'TERM' do
    puts 'Unicorn master intercepting TERM and sending myself QUIT instead'
    Process.kill 'QUIT', Process.pid
  end
end

after_fork do |server, worker|
  Signal.trap 'TERM' do
    puts 'Unicorn worker intercepting TERM and doing nothing. Wait for master to send QUIT'
  end
end

working_directory "/my_project"

listen "/tmp/unicorn.sock", :backlog => 64

stderr_path "/my_project/log/unicorn.stderr.log"
stdout_path "/my_project/log/unicorn.stdout.log"

web-controller.yaml

apiVersion: v1
kind: ReplicationController
metadata:
  name: www-v1
  labels:
    app: www
spec:
  replicas: 2
  selector:
    app: www
    version: v1
  template:
    metadata:
      labels:
        app: www
        version: v1
    spec:
     volumes:
     - name: web-assets
       emptyDir: {}
     - name: web-sock
       emptyDir: {}
     containers:
     - name: web
       image: gcr.io/[your GCE project]/rails-image:v1
       ports:
         - name: web-server
           containerPort: 8080
       env:
        - name: RAILS_ENV
          value: production
        - name: WEB_DATABASE_HOST
          value: db
        - name: SECRET_KEY_BASE
          value: 4fb2a451674dd7c5641577a0031847d82247bd137fedb0ba91c6d1a6ccbc8d2da370ffa164503f50c2f2c121f46f1f21b89dc946633924e0c464bdb69b368415
       volumeMounts:
        - mountPath: /assets
          name: web-assets
        - mountPath: /tmp
          name: web-sock
       lifecycle:
        postStart:
         exec:
          command:
            - /bin/bash
            - -c
            - /my_project/kubernetes-post-start.sh
     - name: nginx
       image: gcr.io/[your GCE project]/nginx-image:v1
       ports:
        - name: http-server
          containerPort: 80
        - name: https-server
          containerPort: 443
       volumeMounts:
       - mountPath: /my_project/public
         name: web-assets
         readOnly: true
       - mountPath: /tmp
         name: web-sock

web-service.json

{
   "kind":"Service",
   "apiVersion":"v1",
   "metadata":{
      "name":"www",
      "labels":{
         "app":"www"
      }
   },
   "spec":{
      "ports": [
         {
           "name": "http",
           "port":80,
           "targetPort":"http-server"
         },
         {
           "name": "https",
           "port":443,
           "targetPort":"https-server"
         }
      ],
      "selector":{
         "app":"www"
      },
      "type": "LoadBalancer"
   }
}