environment

MacOS Catalina 10.15.6
Docker 2.3.0.3
Ruby 2.7.1
Rails 6.0.3.2
Bundler 2.1.4
Gem 3.1.2
Yarn 1.22.5

procedure

Please install Docker in advance.

Get Ruby image

$ docker pull ruby

Launch Docker container

Please change <NAME> and <DIRECTORY> as needed.

$ docker run -i -t --name <NAME> -p 3000:3000 -v "$PWD":<DIRECTORY> /bin/bash

Introducing Rails

Change to your working directory.

$ cd <DIRECTORY>

Next, generate a Gemfile

$ bundle init

Confirm that it has been generated.

$ ls
Gemfile

Install vim for editing. (You can also edit directly from the directory on the host PC)

$ apt-get install vim-tiny

Edit Uncomment the # gem" rails "`` # .

$ vim.tiny Gemfile

`After editing`


# frozen_string_literal: true

source "https://rubygems.org"

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

gem "rails"

Install Gem.

$ bundle install

Create a new Rails project.

$ bundle exec rails new .

Install NodeJS.

$ apt-get install nodejs

I will install Webpacker, but I need Yarn before that, so I will install it. However, if you just apt-get install, it will be installed with the version 0.32 + git, It seems that an error occurs when checking the version of yarn that is performed when webpack: install is performed. ** References: [[Rails] ArgumentError: Malformed version number string 0.32 + What to do if webpacker: install cannot be executed with git](https://qiita.com/TomoProg/items/9497be086d338b3b74cc#%E5%8E% 9F% E5% 9B% A0) **

$ 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 && apt-get install yarn

Install Webpacker.

rails webpacker:install

Start Rails Server

You should be able to start it.

$ bundle exec rails server

In my environment, I couldn't connect locally, so I specified it explicitly and I was able to connect successfully.

$ bundle exec rails server -b 0.0.0.0

=> Booting Puma
=> Rails 6.0.3.2 application starting in development 
=> Run `rails server --help` for more startup options
Puma starting in single mode...
* Version 4.3.6 (ruby 2.7.1-p83), codename: Mysterious Traveller
* Min threads: 5, max threads: 5
* Environment: development
* Listening on tcp://0.0.0.0:3000
Use Ctrl-C to stop
Started GET "/" for 172.17.0.1 at 2020-09-07 09:47:16 +0000
Cannot render console from 172.17.0.1! Allowed networks: 127.0.0.0/127.255.255.255, ::1
   (1.5ms)  SELECT sqlite_version(*)
Processing by Rails::WelcomeController#index as HTML
  Rendering /usr/local/bundle/gems/railties-6.0.3.2/lib/rails/templates/rails/welcome/index.html.erb
  Rendered /usr/local/bundle/gems/railties-6.0.3.2/lib/rails/templates/rails/welcome/index.html.erb (Duration: 6.3ms | Allocations: 295)
Completed 200 OK in 21ms (Views: 12.1ms | ActiveRecord: 0.0ms | Allocations: 1651)

Yay! You're on Rails!

end

** References: Rails on Docker starting from knowledge 0 **

Rails on Docker environment construction procedure