[Rails AWS Docker] Build an existing Ruby on Rails + MySQL application with Docker and deploy it on AWS (1)

This is the way to build a production environment on AWS by turning a Ruby on Rails application created as a portfolio into a Docker container. The portfolio itself is here. [[Portfolio] Overview of the portfolio created during job change activities (Tec camp)] (https://qiita.com/sho_U/items/058e590325ee6833abb0)

I was suffering a lot, so I hope it helps someone.

The articles that I referred to are listed at the end of (6).

Docker containerization of Rails application in local environment

Docker container environment configuration (local version)

The configuration is above. Deploy nginx as a web server. The app server installs puma.

First, containerize your existing Rails app.

Premise

Account created on AWS Account created on docker hub docker installed Rails app running in a local environment

Build

• Please change the fitO2 part to your own app name.

Add the following files to the folder structure of the current application.

docker-compose.yml

Dockerfile

nginx_docker
  ├── Dockerfile
  └── nginx.conf

config
  └── puma.rb

docker-compose.yml

version: '3'
services:
  app:
    build:
      context: .
    command: bundle exec puma -C config/puma.rb

    volumes:
      - .:/fitO2
      - public-data:/fitO2/public
      - tmp-data:/fitO2/tmp
      - log-data:/fitO2/log
    networks:
      - fitO2-network
    depends_on:
      - db

  db:
    image: mysql:5.7
    environment:
      MYSQL_ROOT_PASSWORD: password
      MYSQL_USER: user
      MYSQL_PASSWORD: password
      MYSQL_DATABASE: fitO2_development
    volumes:
      - db-data:/var/lib/mysql
    networks:
      - fitO2-network

  web:
    build:
      context: ./nginx_docker
    volumes:
      - public-data:/fitO2/public
      - tmp-data:/fitO2/tmp
    ports:
      - 80:80
    depends_on:
      - app
    networks:
      - fitO2-network
      
volumes:
  public-data:
  tmp-data:
  log-data:
  db-data:

networks:
  fitO2-network:
    external: true

easy explanation

** db container ** Pull mysql: 5.7 from docker hub with image. Connect 3306 on the host side and 3306 port on the container side with ports. Use the network fitO2-network that is common to the app container side in networks.

** app container ** Specify the Dockerfile directory (context) with build and create a container from the Dockerfile. In volumes, the directory where docker-compose.yml on the host side exists and/fitO2 on the container side are mounted (common). Specify the configuration file with command and start puma (application server). Connect 3000 on the host side and 3000 ports on the container side with ports. It is specified that it will be executed after the app container is created by depends_on. Use the network fitO2-network that is common to the db container side in networks.

** web container ** Create a container from Dockerfile by specifying the directory (context) where ./nginx_docker is located in build. It is specified that it will be executed after the app container is created by depends_on.

FitO2-network is set in ** networks **.

fitO2/Dockerfile.

FROM ruby:2.5.1

RUN apt-get update -qq && \
  apt-get install -y build-essential \
  nodejs\
  mysql-server\
  mysql-client

WORKDIR /fitO2

COPY Gemfile /fitO2/Gemfile
COPY Gemfile.lock /fitO2/Gemfile.lock

RUN gem install bundler
RUN bundle install

RUN mkdir -p tmp/sockets

easy explanation

Install the ruby: 2.5.1 image from docker hub with FROM. The necessary packages are installed in the first RUN. The working directory is set to/fitO2 in WORKDIR. COPY is copying the gemfile and gemfile.lock on the host side to the/fitO directory of the container. Install bundler on the second RUN. Install the package from the gemfile on the third RUN. Creating a 4th RUN socket file.

fitO2/nginx_docker/Dockerfile.

FROM nginx:1.15.8

RUN rm -f /etc/nginx/conf.d/*

ADD nginx.conf /etc/nginx/conf.d/fitO2.conf

#Start Nginx after build is complete
CMD /usr/sbin/nginx -g 'daemon off;' -c /etc/nginx/nginx.conf

easy explanation

Install the nginx: 1.15.8 image from docker hub with FROM. RUN deletes the include directory. Copy the Nginx configuration file to the container with ADD. I try to start Nginx after the build is completed with CMD.

fitO2/nginx_docker/nginx.conf

upstream fitO2 {
  server unix:///fitO2/tmp/sockets/puma.sock;
}

server {
  listen 80;
# =========Switch between local and production===========
  # server_name ◯◯◯.◯◯◯.◯◯◯.◯◯◯;
  server_name localhost;
# ======================================

  access_log /var/log/nginx/access.log;
  error_log  /var/log/nginx/error.log;

  root /fitO2/public;

  client_max_body_size 100m;
  error_page 404             /404.html;
  error_page 505 502 503 504 /500.html;
  try_files  $uri/index.html $uri @fitO2;
  keepalive_timeout 5;

  location @fitO2 {
    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_pass http://fitO2;
  }
}

This is the nginx configuration file. For local environments, set server_name to localhost.

config/puma.rb

threads_count = ENV.fetch("RAILS_MAX_THREADS") { 5 }.to_i
threads threads_count, threads_count
port        ENV.fetch("PORT") { 3000 }
environment ENV.fetch("RAILS_ENV") { "development" }
plugin :tmp_restart

app_root = File.expand_path("../..", __FILE__)
bind "unix://#{app_root}/tmp/sockets/puma.sock"

stdout_redirect "#{app_root}/log/puma.stdout.log", "#{app_root}/log/puma.stderr.log", true

This is the puma configuration file. The bind "unix: // # {app_root} /tmp/sockets/puma.sock" part must match the server in nginx.conf.

reference

config/database.yml

default: &default
  adapter: mysql2
  encoding: utf8
  pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
#Password and Username are docker-compose.Combine with yml
  username: root
  password: password
  host: db

development:
  <<: *default
  database: fitO2_development

test:
  <<: *default
  database: fitO2_test

Create and start container

Change to your app's directory.

Create a container.

docker-compose build

Create a network.

docker network create fitO2-network

Start the container.

docker-compose up

The first time, the database is initialized. Open the terminal in another tab, move directly under the app and enter the following command.

docker-compose exec app rails db:create 
docker-compose exec app rails db:migrate
docker-compose exec app rails db:seed (Not needed without a seeder)

If it doesn't work, or if you make a trial and error, the seeder may be inserted halfway and it may be played due to validation, so delete the database once as shown below and then execute the above command again. please.

docker-compose exec app rails db:drop

http://localhost

You can access the site by visiting.

If an error occurs, check the log in the docker-compose up terminal.

For the time being, I was able to convert an existing application into a Docker container.

Continue to next time (2) Create a VPC on AWS. Create a public subnet.