Rails6 [API mode] + MySQL5.7 environment construction with Docker

Introduction

For myself Rails6 API mode + MySQL5.7 environment construction with Docker (docker compose)

Introduction of Docker itself is omitted

First, create the files necessary for building the environment

• Create the following files
• Top-level directory for apps * Dockerfile * docker-compose.yml * Gemfile * Gemfile.lock

Create & move top level directories for apps

$ cd

$ mkdir sample_app

$ cd sample_app

Create Dockerfile, docker-compose.yml, Gemfile, Gemfile.lock

sample_app$ touch {Dockerfile,docker-compose.yml,Gemfile,Gemfile.lock}

sample_app$ ls
Dockerfile docker-compose.yml Gemfile Gemfile.lock

Write the contents of the file

sample_app/Dockerfile file

Dockerfile

FROM ruby:2.6.5

#Install required packages (Install yarn since Rails 6 has Webpacker)
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 \
		&& apt-get update -qq \
		&& apt-get install -y build-essential libpq-dev nodejs yarn

#Creating a working directory
RUN mkdir /myapp
WORKDIR /myapp

#Add the host side (local) (left side) Gemfile to the container side (right side) Gemfile
ADD ./Gemfile /myapp/Gemfile
ADD ./Gemfile.lock /myapp/Gemfile.lock

#Gemfile bundle install
RUN bundle install
ADD . /myapp

sample_app/docker-compose.yml

docker-compose.yml

version: '3'
services:
  db:
    image: mysql:5.7
    environment:
      MYSQL_ROOT_PASSWORD: password
      MYSQL_DATABASE: root
    ports:
    - "3306:3306"

  web:
    build: .
    command: /bin/sh -c "rm -f tmp/pids/server.pid && bundle exec rails s -p 3001 -b '0.0.0.0'"
    tty: true
    stdin_open: true
    depends_on:
      - db
    ports:
      - "3001:3001"
    volumes:
      - .:/myapp

sample_app/Gemfile

Gemfile

source 'https://rubygems.org'

gem 'rails', '~> 6.0.3'

Gemfile.lock remains empty

Create a Rails app with the docker-compose run command

• Since it is in API mode, the --api option is added.
• Since version 6 or later, --webpacker option is added.

$ docker-compose run web rails new . --force --database=mysql --skip-bundle --api --webpacker

Modify database.yml file

• Describe the DB information created in the container in the sample_app/config/database.yml file.

database.yml

default: &dafault
	adapter: mysql2
	encoding: utf8
	pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
	username: root
	password: password  # docker-compose.yml MYSQL_ROOT_PASSWORD
	host: db    # docker-compose.yml service name

Start a Docker container

• Run container

$ docker-compose build

• Start container
• Perform background execution with the -d option. Doing this will return you to the prompt screen with the container running

$ docker-compose up -d

Create a DB

• If you haven't started the container yet

$ docker-compose up -d

• Confirm container ID

$ docker ps -a

• Enter the container from the confirmed ID

$ docker exec -it <Container ID> /bin/bash

• DB creation

$ rails db:create
$ rails db:migrate

• Get out of the container

$ exit

• When executing locally without entering the container. Run the docker-compose run command after starting the container

$ docker-compose run web rails db:create
$ docker-compose run web rails db:migrate

That's all for construction. Now opens on localhost: 3001.

Other

When stopping the server

--Do not stop with Ctrl + C. The container remains and an error occurs at the next startup --If you do, delete tmp/pids/server.pid and restart with docker-compose up again

$ docker-compose down

Reflect changes in Dockerfile and docker-compose.yml, restart rails server

$ docker-compose up --build

If you want to execute a command such as bundle install

#  docker-compose run {Service name} {Arbitrary command}
$ docker-compose run web bundle install

Connect to MySQL container locally

--Start if the container is not started

$ docker-compose up -d

--Check mysql id

$ docker ps

--Login to MySQL container

$ docker exec -it <MySQL container ID> /bin/bash

$ mysql -u root -p -h 0.0.0.0 -P 3306 --protocol=tcp

mysql>

//escape
mysql> quit

that's all.

Articles that I used as a reference

Rails5 + MySQL on Docker environment construction by too polite Docker-compose (Docker for Mac) [Rails] Building an environment with Rails 6.0 x Docker x MySQL