How to get Firefox and geckodriver to work on Heroku

geckodriver-on-heroku.md

How to get Firefox and geckodriver working with Capybara on Heroku—thank me later

Why all this trouble to use Firefox/geckodriver on Heroku? I had to use Firefox and not Chrome because getting Chromedriver up with proxy credentials I think is impossible actually (not just extremely difficult).

1. Use this Heroku buildpack to install latest Firefox.

Tip: Set your Webdriver path with Selenium::WebDriver::Firefox::Binary.path = "/app/vendor/firefox/firefox"

Tip: To only do this on production branch on Rails.env.production?

2. Use the webdrivers gem, to install latest geckodriver.

Tip: call Webdrivers::Geckodriver.update if you want to force Geckodriver to download

3. Use the headless option for Capybara:

   Capybara.register_driver :selenium_headless do |app|
     browser_options = Selenium::WebDriver::Firefox::Options.new
     browser_options.args << '--headless'
   
     Capybara::Selenium::Driver.new(app, {
       browser: :firefox,
       options: browser_options,
     })
   end
   
   driver = Capybara::Session.new(:selenium_headless)
   driver.visit('https://google.com')
   

4. Add the Heroku Aptfile buildpack and put the following dependencies for Firefox in your Aptfile

libappindicator1 libasound2 libatk1.0-0 libatk-bridge2.0-0 libcairo-gobject2 libgconf-2-4 libgtk-3-0 libice6 libnspr4 libnss3 libsm6 libx11-xcb1 libxcomposite1 libxcursor1 libxdamage1 libxfixes3 libxi6 libxinerama1 libxrandr2 libxss1 libxt6 libxtst6 fonts-liberation

How the flying heck people can figure this out, I don't know. Btw an Aptfile is like a Gemfile that's language agnostic

5. If anything goes wrong, you can get some useful debug output by calling the following:

Selenium::WebDriver.logger.level = :debug
Webdrivers.logger.level = :DEBUG

Also to get a faster feedback loop, run your Capybara code in the rails console on Heroku (heroku ps:exec then rails c). That was big for me.

If you liked this, check out my blog https://rishi.io :)

@RishiHQ I'm following your advice on using the evosystem-jp/heroku-buildpack-firefox but one question: how do you set the Selenium configuration?

Do you add something like GECKODRIVER_PATH and FIREFOX_BIN to the heroku config, or do something like this in the actual repo code?

Selenium::WebDriver::Firefox::Binary.path = "/app/vendor/firefox/firefox"
Selenium::WebDriver::Gecko.path = "/app/vendor/geckodriver/geckodriver"