Using selenium/standalone-chrome docker image within a Ruby / Capybara test suite - ruby

Question

I am attempting to write a Capybara test suite in Ruby (without Rails).
I would like to run the Ruby code in a Docker container.
FROM ruby:2.7
RUN gem install bundler
COPY Gemfile Gemfile
COPY Gemfile.lock Gemfile.lock
RUN bundle install
COPY . .
CMD ["bundle", "exec", "rspec", "spec"]
My tests require a headless version of Chrome which is not available in the Ruby image. I have attempted to create a docker-compose file to include the Ruby code and a headless Chrome image.
version: '3.7'
networks:
mynet:
services:
admin:
container_name: mrt-integ-tests
image: cdluc3/mrt-integ-tests
build:
context: .
dockerfile: Dockerfile
volumes:
- type: bind
source: ./config/test_config.yml
target: /config/test_config.yml
stdin_open: true
tty: true
networks:
mynet:
depends_on:
- chrome
chrome:
container_name: chrome
image: selenium/standalone-chrome
ports:
- published: 4444
target: 4444
networks:
mynet:
This is how I am attempting to create my Capybara session:
Capybara.register_driver :selenium_chrome do |app|
args = ['--no-default-browser-check', '--start-maximized', '--headless', '--disable-dev-shm-usage']
caps = Selenium::WebDriver::Remote::Capabilities.chrome("chromeOptions" => {"args" => args})
Capybara::Selenium::Driver.new(
app,
browser: :remote,
desired_capabilities: caps,
url: "http://chrome:4444/wd/hub"
)
end
#session = Capybara::Session.new(:selenium_chrome)
When I start my containers, I see the following error.
chrome | 05:39:44.350 INFO [GridLauncherV3.lambda$buildLaunchers$3] - Launching a standalone Selenium Server on port 4444
chrome | 2020-06-04 05:39:44.420:INFO::main: Logging initialized #766ms to org.seleniumhq.jetty9.util.log.StdErrLog
chrome | 05:39:44.920 INFO [WebDriverServlet.<init>] - Initialising WebDriverServlet
chrome | 05:39:45.141 INFO [SeleniumServer.boot] - Selenium Server is up and running on port 4444
chrome | 05:39:47.431 INFO [ActiveSessionFactory.apply] - Capabilities are: {
chrome | "browserName": "chrome",
chrome | "chromeOptions": {
chrome | "args": [
chrome | "--no-default-browser-check",
chrome | "--start-maximized",
chrome | "--headless",
chrome | "--disable-dev-shm-usage"
chrome | ]
chrome | },
chrome | "cssSelectorsEnabled": true,
chrome | "javascriptEnabled": true,
chrome | "nativeEvents": false,
chrome | "rotatable": false,
chrome | "takesScreenshot": false,
chrome | "version": ""
chrome | }
chrome | 05:39:47.435 INFO [ActiveSessionFactory.lambda$apply$11] - Matched factory org.openqa.selenium.grid.session.remote.ServicedSession$Factory (provider: org.openqa.selenium.chrome.ChromeDriverService)
chrome | Starting ChromeDriver 83.0.4103.39 (ccbf011cb2d2b19b506d844400483861342c20cd-refs/branch-heads/4103#{#416}) on port 13554
chrome | Only local connections are allowed.
chrome | Please see https://chromedriver.chromium.org/security-considerations for suggestions on keeping ChromeDriver safe.
chrome | ChromeDriver was started succ[e1s5s9f1u2l4l9y1.8
chrome | 7.473][SEVERE]: bind() failed: Cannot assign requested address (99)
chrome | 05:39:48.211 INFO [ProtocolHandshake.createSession] - Detected dialect: W3C
chrome | 05:39:48.247 INFO [RemoteSession$Factory.lambda$performHandshake$0] - Started new session 1ed95304843a1d5ab904708d998710a0 (org.openqa.selenium.chrome.ChromeDriverService)
What suggestions do you have to resolve this error?

Answer 1

I have a partial solution here. Adding --whitelisted-ips to my browser options makes my tests function. See https://github.com/RobCherry/docker-chromedriver/issues/15
args = ['--no-default-browser-check', '--start-maximized', '--headless', '--disable-dev-shm-usage']
to
args = ['--no-default-browser-check', '--start-maximized', '--headless', '--disable-dev-shm-usage', '--whitelisted-ips']
Interestingly, the following error is still generated in the chrome container.
[1591286416.104][SEVERE]: bind() failed: Cannot assign requested address (99)

Answer 2

You need to setup whitelisted-ips argument for chromedriver executable. You can achive it by set env JAVA_OPTS for docker chrome-node image. In your case:
chrome:
container_name: chrome
image: selenium/standalone-chrome
ports:
- published: 4444
target: 4444
environment:
- JAVA_OPTS=-Dwebdriver.chrome.whitelistedIps=
networks:
mynet: