mechetel/rails_nginx_docker

Create Ruby On Rails app using docker puma postgres nginx

Create Rails Docker file with nginx and puma

At first, create rails container and access it directly.

$ mkdir sample_rails_nginx && cd $_

Directory for create Dockerfile

$ mkdir -p docker/app

Docker file for rails

$ nano docker/app/Dockerfile

	# Base ruby image:
	FROM ruby:2.3.3
	# Install ruby dependencies
	RUN apt-get update -qq && apt-get install -y build-essential libpq-dev nodejs
	# create application directory inside ruby image
	RUN mkdir /myapp
	# Set our working directory inside the image
	WORKDIR /myapp
	ADD Gemfile /myapp/Gemfile
	ADD Gemfile.lock /myapp/Gemfile.lock
	RUN bundle install
	ADD . /myapp
	EXPOSE 3000
	CMD [ "bundle", "exec", "puma", "-C", "config/puma.rb" ]

Create docker-compose file

$ nano docker-compose.yml

	version: '3'
	services:
	  app:
	    build:
	      context: .
	      dockerfile: ./docker/app/Dockerfile
	    volumes:
	      - .:/myapp
	    depends_on:
	      - db
	    ports:
	      - 3000:3000
	  db:
	    image: postgres


$ bundle init

Add rails gem in Gemfile

$ nano Gemfile

gem "rails"

Add Gemfile.lock

$touch Gemfile.lock

Install gems and create rails project.

You may be asked if you wanna overwrite gemfile, then press ‘Y’.

$ docker-compose run app bundle exec rails new . -d postgresql

Set db host to postgres container. This is just sample, and define properly username and password. $ nano config/database.yml

   default: &default
   adapter: postgresql
   encoding: unicode
   host: db
   username: postgres
   pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>

Note: Remember must remove/comment out username and password field in production section on database.yml

Now build docker image and create database.

$ docker-compose build
$ docker-compose run app bundle exec rails db:create RAILS_ENV=production

Run application.

$ docker-compose up

Check your browser with http://localhost:3000

Open another command window/tab.

Check all containers work well.

	$ docker-compose ps
	     Name                   Command               State           Ports
	--------------------------------------------------------------------------------
	samplerailsnginx_web_1   bundle exec puma -C config ...   Up      0.0.0.0:3000->3000/tcp
	samplerailsnginx_db_1    docker-entrypoint.sh postgres    Up      5432/tcp

Then check localhost:3000 which is Rails default welcome page.

Press ctrl+c to stop all those container.

Now add Nginx’s container

Create a directory which is related to nginx container.

$ mkdir docker/web

Add nginx config file to proxy rails application.

$ nano docker/web/app.conf

	upstream puma_rails_app {
	  server app:3000;
	}
	server {
	  listen       80;
	  proxy_buffers 64 16k;
	  proxy_max_temp_file_size 1024m;
	  proxy_connect_timeout 5s;
	  proxy_send_timeout 10s;
	  proxy_read_timeout 10s;
	  location / {
	    try_files $uri $uri/ @rails_app;
	  }
	  location @rails_app {
	    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
	    proxy_set_header Host $http_host;
	    proxy_redirect off;
	    proxy_pass http://puma_rails_app;
	    # limit_req zone=one;
	    access_log /var/www/sample_rails_nginx/log/nginx.access.log;
	    error_log /var/www/sample_rails_nginx/log/nginx.error.log;
	  }
	}

Create docker file for nginx.

$ nano docker/web/Dockerfile

	# Base nginx image:
	FROM nginx
	# Install nginx dependencies
	RUN apt-get update -qq && apt-get -y install apache2-utils
	# establish where Nginx should look for files
	ENV RAILS_ROOT /var/www/sample_rails_nginx
	# Set our working directory inside the image
	WORKDIR $RAILS_ROOT
	# create log directory
	RUN mkdir log
	# copy over static assets
	COPY public public/
	# Copy Nginx config template
	COPY docker/web/app.conf /tmp/docker_example.nginx
	# substitute variable references in the Nginx config template for real values from the environment
	# put the final config in its place
	RUN envsubst '$RAILS_ROOT' < /tmp/docker_example.nginx > /etc/nginx/conf.d/default.conf
	EXPOSE 80
	# Use the "exec" form of CMD so Nginx shuts down gracefully on SIGTERM (i.e. `docker stop`)
	CMD [ "nginx", "-g", "daemon off;" ]

Change docker-compose file to create nginx container. Now add the nginx in docker-compose file $ nano docker-compose.yml

	version: '3'
	services:
	  web:
	    build:
	      context: .
	      dockerfile: ./docker/web/Dockerfile
	    depends_on:
	      - app
	    ports:
	      - 8080:80
	  app:
	    build:
	      context: .
	      dockerfile: ./docker/app/Dockerfile
	    volumes:
	      - .:/myapp
	    depends_on:
	      - db
		  - ports:
	      - 3000:3000
	  db:
	    image: postgres

Build and run the docker image

$ docker-compose build
$ docker-compose up

All containers work well.

	$ docker-compose ps
	     Name                   Command                     State          Ports
	---------------------------------------------------------------------------------
	samplerailsnginx_app_1   bundle exec puma -C config ...   Up     	 3000/tcp
	samplerailsnginx_db_1    docker-entrypoint.sh postgres    Up      	 5432/tcp
	samplerailsnginx_web_1   nginx -g daemon off;             Up       	 0.0.0.0:8080->80/tcp

Now check the localhost:8080, rails’s welcome page.