DockerでRails6＋PostgreSQLの開発環境を構築する

$ mkdir rails-app
$ cd rails-app

$ touch Gemfile
$ touch Gemfile.lock

source "https://rubygems.org"
git_source(:github) {|repo_name| "https://github.com/#{repo_name}" }

gem "rails", "6.1.5"

FROM ruby:2.7.5

RUN apt-get update -qq && apt-get install -y build-essential postgresql-client

WORKDIR /myapp

# install nodejs(LTS)
RUN curl -fsSL https://deb.nodesource.com/setup_lts.x | bash - && apt-get install -y nodejs

# npm自体のバージョンを最新にする
RUN npm install -g npm

# install yarn
RUN npm install -g yarn

# gem
COPY Gemfile /myapp/
COPY Gemfile.lock /myapp/
RUN gem install bundler
RUN bundle install

# コンテナー起動時に毎回実行されるスクリプトを追加
COPY entrypoint.sh /usr/bin/
RUN chmod +x /usr/bin/entrypoint.sh
ENTRYPOINT ["entrypoint.sh"]

# 3000番ポートをリンクしたサービスのみに公開
EXPOSE 3000

#!/bin/bash
set -e

# server.pidが残っているとrailsが起動できないので削除する
rm -f /myapp/tmp/pids/server.pid

# コンテナーのプロセスを実行する(Dockerfile 内の CMD に設定されているもの)
exec "$@"

version: "3.9"
services:
  db:
    image: postgres:14.2
    container_name: rails-app_db
    volumes:
      - pgdata:/var/lib/postgresql/data
    environment:
      POSTGRES_USER: devuser
      POSTGRES_PASSWORD: devuser
      POSTGRES_INITDB_ARGS: "--encoding=UTF-8 --locale=C"
    networks:
      - mynetwork

  web:
    image: rails-app_web
    build:
      context: .
      dockerfile: Dockerfile
    container_name: rails-app_web
    command: bash -c "bundle install && yarn install --check-files && rm -f tmp/pids/server.pid && bundle exec pumactl start"
    environment:
      TZ: Asia/Tokyo
      RAILS_ENV: development
    volumes:
      - .:/myapp
      - bundle:/usr/local/bundle
      - node_modules:/myapp/node_modules
    ports:
      - "3000:3000"
    depends_on:
      - db
    networks:
      - mynetwork

networks:
  mynetwork:
    name: rails-app

volumes:
  pgdata:
    name: rails-app_pgdata
  bundle:
    name: rails-app_bundle
  node_modules:
    name: rails-app_node_modules
  

$ git init
$ git add -A
$ git commit -m "initial commit"

$ docker-compose run web rails new . --force --no-deps --database=postgresql \
--skip-action-cable --skip-turbolinks --skip-test \
--skip-bundle --skip-webpack-install

$ sudo chown -R ${USER}:${USER} .

source 'https://rubygems.org'
git_source(:github) { |repo| "https://github.com/#{repo}.git" }

ruby '2.7.5'

gem 'rails', '~> 6.1.5'
gem 'pg', '~> 1.2.3'
gem 'puma'
gem 'sass-rails'
gem 'webpacker'
gem 'jbuilder'
gem 'bcrypt'
gem 'bootsnap', require: false
gem 'tzinfo-data'

group :development do
  gem 'web-console'
  gem 'listen'
  gem 'spring'
end

$ git add -A
$ git commit -m "railsプロジェクトを作成"

$ docker-compose build

default: &default
  adapter: postgresql
  encoding: unicode
  pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
  port: 5432
  host: db
  username: devuser
  password: devuser

development:
  <<: *default
  database: myapp_dev

test:
  <<: *default
  database: myapp_test

production:
  <<: *default
  database: myapp_production
  username: <%= ENV["DATABASE_USERNAME"] %>
  password: <%= ENV["DATABASE_PASSWORD"] %>
  host: <%= ENV["DATABASE_HOST"] %>

$ docker-compose run web bundle install

$ docker-compose run web bin/rails webpacker:install

$ docker-compose run web bin/rails db:create

[+] Running 3/1
 ⠿ Network rails-app          Created                                                                                                                      0.1s
 ⠿ Volume "rails-app_pgdata"  Created                                                                                                                      0.0s
 ⠿ Container rails-app_db     Created                                                                                                                      0.0s
[+] Running 1/1
 ⠿ Container rails-app_db  Started                                                                                                                         0.4s
Running via Spring preloader in process 20
Created database 'myapp_dev'
Created database 'myapp_test'

$ docker-compose up

rails-app_web  | => Booting Puma
rails-app_web  | => Rails 6.1.5 application starting in development
rails-app_web  | => Run `bin/rails server --help` for more startup options
rails-app_web  | Puma starting in single mode...
rails-app_web  | * Puma version: 5.6.4 (ruby 2.7.5-p203) ("Birdie's Version")
rails-app_web  | *  Min threads: 5
rails-app_web  | *  Max threads: 5
rails-app_web  | *  Environment: development
rails-app_web  | *          PID: 1
rails-app_web  | * Listening on http://0.0.0.0:3000
rails-app_web  | Use Ctrl-C to stop