Capybara/Selenium/Firefox/Proxy.

gistfile1.rb

  require 'capybara/firebug'            
  # Disable Webmock if needed.
  WebMock.disable_net_connect!(allow_localhost: true)
  # Same thing for VCR if it has been imported somewhere.
  VCR.configure do |c|                                                                                                                                                             
    c.ignore_localhost = true                                                                                                                                                      
  end                                                                                                                                                                              
                                                                                                                                                                                   
  ENV['NO_PROXY'] = ENV['no_proxy'] = '127.0.0.1'                                                                                                                                  
                                                                                                                                                                                   
  Capybara.app_host = 'http://127.0.0.1:3000'                                                                                                                                    
  Capybara.server_port = 3000                                                                                                                                                      
  Capybara.default_driver = :selenium                                                                                                                                              
  Capybara.default_selector = :css                                                                                                                                                 
  Capybara.default_wait_time = 10                                                                                                                                                  
                                                                                                                                                                                   
  Capybara.register_driver :selenium do |app|                                                                                                                                      
    # Use an existing profile                                                                                                                                                      
    profile = Selenium::WebDriver::Firefox::Profile.new('/path/to/Firefox/Profiles/blahblah.test')                                          
                                                                                                                                                                                   
    profile.enable_firebug                                                                                                                                                         
                                                                                                                                                                                   
    # Configure proxy manually.                                                                                                                                                    
    profile["network.proxy.type"] = 1     
    # Auto-detect proxy = 4
    # No proxy = 3
    # Use system proxy settings = 5
    profile["network.proxy.http"] = 'localhost'                                                                                                                              
    profile["network.proxy.http_port"] = 3128                                                                                                                                      
                                                                                                                                                                                   
    Capybara::Selenium::Driver.new(app, browser: :firefox, profile: profile)                                                                                                       
  end                                                                                                                                                                              
                                                                                                                                                                                   
  # Uncomment to run against standalone server.                                                                                                                                    
  #Capybara.run_server = false 

Here's my code that works in July 2020:

  # entrypoint
  def start_capybara_with_proxy(url)
    proxy_address = format(
      '%s:%s',
      BLAZING_SEO_PROXY_HOST,
      BLAZING_SEO_PROXY_PORTS.sample
    )
    proxy = Selenium::WebDriver::Proxy.new(
      http: proxy_address,
      ssl: proxy_address
    )
    start_capybara(url, proxy)
  end

  def start_capybara(url, proxy = nil)
    configure_driver(proxy)
    @driver = Capybara::Session.new(:selenium_headless)
    @driver.visit(url)
  end

  def configure_driver(proxy)
    Selenium::WebDriver::Firefox::Binary.path = '/app/vendor/firefox/firefox' if Rails.env.production?

    Capybara.register_driver :selenium_headless do |app|
      browser_options = Selenium::WebDriver::Firefox::Options.new
      browser_options.args << '--headless' unless ENV['HEADLESS'] == 'false'
      desired_caps = Selenium::WebDriver::Remote::Capabilities.firefox(
        proxy: proxy
      )
      Capybara::Selenium::Driver.new(
        app,
        browser: :firefox,
        desired_capabilities: desired_caps,
        options: browser_options
      )
    end
  end

Unfortunately, I realize I need to get proxy working with username and password (like @tchret), which has been a headache.

Does anyone know how to do this on either Chrome/Chromedriver or on Firefox/geckodriver? On Firefox, I believe it involves downloading an extension, and setting username/password through that. I was unable to fill out the popup username/password prompt through Capybara