This buildpack downloads and installs Xvfb and Google Chrome from your choice of release channels.
Note that Google Chrome now has a --headless flag, so for many applications,
Xvfb may not be required. If so, consider this buildpack instead.
You can choose your Chrome release channel by specifying GOOGLE_CHROME_CHANNEL as
a config var for your app, in your app.json (for Heroku CI and Review Apps),
or in your pipeline settings (for Heroku CI).
Valid values are stable, beta, and unstable. If unspecified, the stable
channel will be used.
This buildpack installs shims that always add --disable-gpu
and --no-sandbox to any google-chrome command as you'll have trouble
running Chrome on a Heroku dyno otherwise.
You'll have two of these shims on your path: google-chrome and
google-chrome-$GOOGLE_CHROME_CHANNEL. They both point to the binary of
the selected channel.
To use Selenium with this buildpack, you'll also need Chrome's webdriver. This buildpack does not install chromedriver, but there is a chromedriver buildpack also available.
Additionally, chromedriver expects Chrome to be installed at /usr/bin/google-chrome,
but that's a read-only filesystem in a Heroku slug. You'll need to tell Selenium/chromedriver
that the chrome binary is at /app/.apt/usr/bin/google-chrome instead.
To make that easier, this buildpack makes $GOOGLE_CHROME_BIN available as
an environment variable. With it, you can use the standard location
locally and the custom location on Heroku. An example configuration for Ruby's
Capybara:
chrome_bin = ENV.fetch('GOOGLE_CHROME_BIN', nil)
chrome_opts = chrome_bin ? { "chromeOptions" => { "binary" => chrome_bin } } : {}
Capybara.register_driver :chrome do |app|
Capybara::Selenium::Driver.new(
app,
browser: :chrome,
desired_capabilities: Selenium::WebDriver::Remote::Capabilities.chrome(chrome_options)
)
end