Rails6.0環境をDockerで作る手順を真面目にやると１日が終わるのでシェルにした。

前提

Docker, Docker-composeが入っていること

使い方

# ディレクトリを作成
$ mkdir my-rails-app
$ cd my-rails-app

# 以下に書いたシェルの内容をcreate-rails.shなどといったファイル名で保存して実行。
$ ./create-rails.sh
$ docker-compose up

シェル

#!/bin/bash
###########################################################################
# DockerでRailsアプリを新規作成し、開発できる状態にするシェルスクリプト
# Rails: 6.0
# Ruby: 2.6.5
# DB: Mysql 5.7.19
###########################################################################

# Dockerfile作成
cat << _EOT_ > ./Dockerfile
FROM ruby:2.6.5

RUN curl -sS https://dl.yarnpkg.com/debian/pubkey.gpg | apt-key add - && echo "deb https://dl.yarnpkg.com/debian/ stable main" | tee /etc/apt/sources.list.d/yarn.list

RUN apt-get update -qq && apt-get install -y nodejs yarn
RUN mkdir /myapp
WORKDIR /myapp
COPY Gemfile /myapp/Gemfile
COPY Gemfile.lock /myapp/Gemfile.lock
RUN bundle install
COPY . /myapp

EXPOSE 3000

# Start the main process.
CMD ["rails", "server", "-b", "0.0.0.0"]
_EOT_

# Gemfile, Gemfile.lock作成
cat << _EOT_ > ./Gemfile
source 'https://rubygems.org'
gem 'rails', '~>6'
_EOT_
touch Gemfile.lock

# docker-compose.yml作成
cat << _EOT_ > ./docker-compose.yml
version: '3'
services:
  db:
    image: mysql:5.7.19
    environment:
      - MYSQL_ROOT_PASSWORD=root
    ports:
      - "3306:3306"
    volumes:
      - ./tmp/db:/var/lib/mysql
  web:
    build: .
    command: bash -c "rm -f tmp/pids/server.pid && bundle exec rails s -p 3000 -b '0.0.0.0'"
    volumes:
      - .:/myapp
      - bundle-data:/usr/local/bundle
    ports:
      - "3000:3000"
    depends_on:
      - db
volumes:
  bundle-data:
_EOT_

docker-compose run web rails new . --force --no-deps --database=mysql --webpacker
docker-compose build

rm -rf ./config/database.yml
cat << _EOT_ > ./config/database.yml

default: &default
  adapter: mysql2
  encoding: utf8mb4
  pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
  username: root
  password: root
  host: db

development:
  <<: *default
  database: myapp_development

test:
  <<: *default
  database: myapp_test

production:
  <<: *default
  database: myapp_production
  username: myapp
  password: <%= ENV['MYAPP_DATABASE_PASSWORD'] %>

_EOT_

docker-compose run web rails db:create