Failed to find Chrome binary について

前提

本日学んだことを書いていきます。
Docker
Ruby on Rails
Ruby

本題

Capybara でのテスト実行時に以下のようなエラーが出てしまい、ハマりました。。。

Failure/Error: visit login_path

          Webdrivers::BrowserNotFound:
            Failed to find Chrome binary.

Chrome binary が見つからない？
Chrome がないのが原因？
Docker環境内のためChromeが入っていないのかなと思いました。

解決方法

capybara.rb

#変更前
Capybara.register_driver :chrome_headless do |app|
  options = ::Selenium::WebDriver::Chrome::Options.new

  options.add_argument('--headless')
  options.add_argument('--no-sandbox')
  options.add_argument('--disable-dev-shm-usage')
  options.add_argument('--window-size=1400,1400')

  Capybara::Selenium::Driver.new(app, browser: :chrome, options: options)
end

Capybara.javascript_driver = :chrome_headless

RSpec.configure do |config|
  config.before(:each, type: :system) do
    driven_by :rack_test
  end

  config.before(:each, type: :system, js: true) do
    driven_by :chrome_headless
  end
end

capybara.rb

#変更後
Capybara.register_driver :chrome_headless do |app|
  options = ::Selenium::WebDriver::Chrome::Options.new

  options.add_argument('--headless')
  options.add_argument('--no-sandbox')
  options.add_argument('--disable-dev-shm-usage')
  options.add_argument('--window-size=1400,1400')

  Capybara::Selenium::Driver.new(app, browser: :chrome, options: options)
end

Capybara.javascript_driver = :chrome_headless

RSpec.configure do |config|
  config.before(:each, type: :system) do
    driven_by :rack_test
  end

  config.before(:each, type: :system, js: true) do
    if ENV["SELENIUM_DRIVER_URL"].present?
      driven_by :selenium, using: :chrome, options: {
        browser: :remote,
        url: ENV.fetch("SELENIUM_DRIVER_URL"),
        desired_capabilities: :chrome
      }
    else
      driven_by :selenium_chrome_headless
    end
  end
end

docker-compose.yml

#変更前
version: '3'
services:
  web:
    build: .
    command: bundle exec rails s -p 3000 -b '0.0.0.0'
    volumes:
      - .:/app
    ports:
      - 3000:3000
    depends_on:
      - db
    tty: true
    stdin_open: true
  db:
    image: mysql:5.7
    volumes:
      - db-volume:/var/lib/mysql
    environment:
      MYSQL_ROOT_PASSWORD: password
volumes:
  db-volume:

docker-compose.yml

#変更後
version: '3'
services:
  web:
    build: .
    command: bundle exec rails s -p 3000 -b '0.0.0.0'
    volumes:
      - .:/app
    ports:
      - 3000:3000
    depends_on:
      - db
    tty: true
    stdin_open: true
    environment: #以下追記
    - "SELENIUM_DRIVER_URL=http://selenium_chrome:4444/wd/hub"
  selenium_chrome:
    image: selenium/standalone-chrome-debug
    logging:
      driver: none
  db:
    image: mysql:5.7
    volumes:
      - db-volume:/var/lib/mysql
    environment:
      MYSQL_ROOT_PASSWORD: password
volumes:
  db-volume:

上記設定で解決しました。