Rspec with headless Chrome/Chromium on Alpine Linux

Question

On Alpine 3.10.1, I'm trying to run RSpec with headless_chrome.

 config.before(:each, type: :system, js: true) do
    driven_by :selenium, using: :headless_chrome
  end

I have installed capybara and webdrivers.

Since I haven't found a way to install Chrome on Alpine, I have tried with Chromium (76.0.3809.87-r0). But, when I run the spec, it doesn't find the driver.

ChildProcess::LaunchError: No such file or directory - /root/.webdrivers/chromedriver

I have tried also to install chromium-chromedriver directly via apk but the outcome has been the same.

Is there a way to install Chrome on Alpine or to use Chromium with Capybara?

Anticline

I'm facing this too — tests previously running successfully with Chromium installed under /usr/bin/chromium-browser. Switching to webdrivers/selenium-webdriver gives the error you're seeing. Even with WD_CHROME_PATH set. The file chromedriver is actually there any the Jenkins user has permiissions for it too. – Kmeson

We had this kind of errors in the past. Not sure it can help you but here is an extract of part of our patch for Linux platforms: "Selenium::WebDriver::Chrome.path = (which chromium.presence || which chromium-browser).chomp" – Yale

Answer 1

There are three things necessary to get this working:

1. Use selenium-webdriver instead of webdrivers
2. Install chromium, chromium-chromedriver and selenium on your Docker image
3. Configure a Capybara driver

Details below.

Use selenium-webdriver instead of webdrivers

If you happen to be using the webdrivers gem in your Gemfile, replace it with selenium-webdriver.

Install chromium, chromium-chromedriver and selenium on your Docker image

Alter your Dockerfile so that the following packages are being installed:

chromium chromium-chromedriver python3 python3-dev py3-pip

Then, after that, include the line RUN pip3 install -U selenium.

Below is a full sample Dockerfile.

FROM ruby:2.7.2-alpine AS builder

RUN apk add --no-cache \
    build-base libffi-dev \
    nodejs yarn tzdata \
    postgresql-dev postgresql-client zlib-dev libxml2-dev libxslt-dev readline-dev bash \
    #
    # For testing
    chromium chromium-chromedriver python3 python3-dev py3-pip \
    #
    # Nice-to-haves
    git vim \
    #
    # Fixes watch file issues with things like HMR
    libnotify-dev

RUN pip3 install -U selenium

FROM builder AS development

# Add the current apps files into docker image
RUN mkdir -p /usr/src/app
WORKDIR /usr/src/app

# Install any extra dependencies via Aptfile - These are installed on Heroku
# COPY Aptfile /usr/src/app/Aptfile
# RUN apk add --update $(cat /usr/src/app/Aptfile | xargs)

ENV PATH /usr/src/app/bin:$PATH

# Install latest bundler
RUN bundle config --global silence_root_warning 1

EXPOSE 3000
CMD ["rails", "server", "-b", "0.0.0.0", "-p", "3000"]

FROM development AS production

COPY Gemfile /usr/src/app
COPY .ruby-version /usr/src/app
COPY Gemfile.lock /usr/src/app

COPY package.json /usr/src/app
COPY yarn.lock /usr/src/app

# Install Ruby Gems
RUN bundle config set deployment 'true'
RUN bundle config set without 'development:test'
RUN bundle check || bundle install --jobs=$(nproc)

# Install Yarn Libraries
RUN yarn install --check-files

# Copy the rest of the app
COPY . /usr/src/app

# Precompile the assets
RUN RAILS_SERVE_STATIC_FILES=enabled SECRET_KEY_BASE=secret-key-base RAILS_ENV=production RACK_ENV=production NODE_ENV=production bundle exec rake assets:precompile

# Precompile Bootsnap
run RAILS_SERVE_STATIC_FILES=enabled SECRET_KEY_BASE=secret-key-base RAILS_ENV=production RACK_ENV=production NODE_ENV=production bundle exec bootsnap precompile --gemfile app/ lib/

Configure a Capybara driver

Put the following in spec/support/chrome.rb.

# spec/support/chrome.rb

driver = :selenium_chrome_headless

Capybara.server = :puma, {Silent: true}

Capybara.register_driver driver 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 = driver

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

I wrote up a little more detail in a blog post I wrote on this topic.

Primitive

Thanks for the detailed answer (and blog post)! I was wondering if you could discuss why selenium-webdriver vs webdrivers (as webdrivers was the pointed to from the deprecated chromedriver-helper)? Any substantial differences? I'm haven't done front-end testing in a long time, so just trying to get a better feel for the current situation as I try to jump back in. Thanks! – Engadine

Sorry, I wish I could remember but I can't. My fuzzy memory is that webdrivers gave some kind of error or failed in some way like that. – Primitive

Answer 2

Jason Swett's answer ultimately works but it has a lot of overhead. Most notably to get Capybara working on Alpine I didn't need to install Selenium or Python.

The simplest way I found to get RSpec + Capybara working on Alpine:

Dockerfile

FROM ruby:3.0.2-alpine

RUN apk --update add --no-cache chromium chromium-chromedriver

Gemfile

group :test do
  gem 'capybara' # 3.36.0 as of writing this
  gem 'selenium-webdriver' # 4.0.3 as of writing this
  # Make sure no other gems are installed, such as `webdrivers`
end

rails_helper.rb

Capybara.register_driver :headless_chromium 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=1280,900")
  Capybara::Selenium::Driver.new(app, browser: :chrome, capabilities: options)
end
Capybara.javascript_driver = :headless_chromium

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