Hello. This time, I summarized the procedure to introduce Docker to the development environment of the existing Rails application. I haven't studied enough yet, so I would appreciate it if you could point out any corrections or improvements.

Advance preparation

-Install Docker-for-mac --Existing Rails app (This time I will use the simple household account book app I created earlier.)

environment

Ruby:2.5.3 Rails:5.2.4.3 MySQL:5.6 Docker:19.03.8 docker-compose:1.25.4

procedure

1. Add Dockerfile, docker-compose.yml to the root directory

Create Dockerfile and docker-compose.yml directly under the root directory of your existing Rails app. Below are the contents of each file.

Dockerfile


FROM ruby:2.5.3
RUN apt-get update && apt-get install -y \
    build-essential \
    nodejs
WORKDIR /kakeibo
COPY Gemfile Gemfile.lock /kakeibo/
RUN bundle install

--For the FROM ruby: 2.5.3 part, match it with the Ruby version of the app. --RUN apt-get update && apt-get install -y ~ to install the required packages. --Create a folder in the container with WORKDIR / kakeibo. --Copy Gemfile and Gemfile.lock into the container with COPY Gemfile Gemfile.lock / kakeibo /, then run bundle install.

docker-compose.yml

version: '3'

volumes:
  mysql-data:

services:
  web:
    build: .
    command: bundle exec rails s -p 3000 -b '0.0.0.0'
    ports:
      - '3000:3000'
    volumes:
      - '.:/kakeibo'
    tty: true
    stdin_open: true
    depends_on:
      - db
    links:
      - db

  db:
    image: mysql:5.6
    volumes:
      - 'mysql-data:/var/lib/mysql'
    environment:
      - 'MYSQL_ROOT_PASSWORD=password'

A detailed explanation of the contents of Dockerfile and docker-compose.yml is summarized in this article.

2. Edit config / database.yml

default: &default
  adapter: mysql2
  encoding: utf8
  pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
  username: root
  password: password
  host: db

development:
  <<: *default
  database: kakeibo_development

Match the password and host in config / database.yml to the values set in docker-compose.yml.

3. Start container

$ docker-compose build
$ docker-compose up -d
$ docker-compose exec web rails db:create
$ docker-compose exec web rails db:migrate

Now when you visit http: // localhost: 3000, you should be able to see the app successfully.

reference

-Procedure for developing an existing rails project with Docker -Procedure to install Docker in existing Rails app -Create an existing application development environment with Docker [Ruby2.6 + Rails5.2 + Mysql5.7] -[Rails] Procedure for creating Rails + MySQL development environment with Docker -Docker beginners carefully summarize the procedure for building a virtual environment with Rails + PostgreSQL or MySQL -#Linux #Ubuntu #docker #Dockerfile What is this? apt-get install --no-install-recommends -"Dockerfile Best Practices"

Procedure for introducing Docker into the development environment of existing Rails applications [Rails, MySQL, Docker]