Setting up Wallaby with Docker Compose, Chrome and Selenium

I don’t have any experience with Wallaby, chrome or selenium, but I have some with Docker.

Can you try:

 "http://hub:4444/wd/hub/",

So you are replacing localhost by the name of the service in docker compose, because that’s how containers communicate between them. Using localhost inside a container will reach the container internal network, not the your host network or the other container network.

Nope didn’t work

There has to be a way for it to work with containers but can’t figure it out.

Are you trying to use the Chromedriver Wallaby backend or the Selenium Wallaby backend? If you have both of the above lines in your config, you’ll end up using Selenium. I am not familiar with how the selenium/hub and selenium/node-chrome docker images work but it seems that they are exposing Selenium.

Looking at the Feature module documentation, won’t that result in the test trying to create two browser instances? I think the feature macro will call start_session for you already, but I may be wrong.

I think to set capabilities when using the feature macro, the @sessions module attribute should be used. But you should double check with the documentation.

Are you sure that Firefox is available to be started by your selenium hub? You can check that by navigating to http://localhost:4444/wd/hub/ in your browser, clicking Create Browser and selecting Firefox in the dropdown.

Hi there,

I have been setting up Wallaby in docker with my new Phoenix app and today I finished setting up. It works very well and I have no problems, but I am using the default Wallaby.Chrome driver.

Out of curiousity, I added this one line to my config/test.exs:

config :wallaby, driver: Wallaby.Selenium

and ran the tests again. I immediately got this error:

** (RuntimeError) Wallaby had an internal issue with HTTPoison:
     %HTTPoison.Error{id: nil, reason: :checkout_timeout}
     %HTTPoison.Error{id: nil, reason: :econnrefused}
     stacktrace:
       (wallaby 0.26.2) lib/wallaby/httpclient.ex:50: Wallaby.HTTPClient.make_request/5
       (wallaby 0.26.2) lib/wallaby/selenium.ex:92: Wallaby.Selenium.start_session/1

which seems to be the same problem as you.

Then I saw this:

https://github.com/elixir-wallaby/wallaby/issues/351

which describes the same problem over two years ago.

I strongly recommend not using Wallaby.Selenium and sticking with the default Wallaby.Chrome driver.

The Wallaby.Chrome driver will start chromedriver for you, whereas the Wallaby.Selenium driver does not start the selenium server automatically. I believe you are getting that error because you have not started the selenium server.

This issue you linked is regarding the old phantom js driver, so I don’t think it is relevant.

For the top-level post, to get selenium to run using chrome and Wallaby.Feature, you can set the default capabilities in your application config to use chrome

config :wallaby,
  driver: Wallaby.Selenium,
  selenium: [
    capabilities: %{
      javascriptEnabled: true,
      browserName: "chrome",
      "chromeOptions": %{
         args: [
           "--no-sandbox",
           "window-size=1280,800",
           "--disable-gpu",
           "--headless",
           "--fullscreen",
           "--user-agent=Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/41.0.2228.0 Safari/537.36"
        ]
      }
    }
  ]

If you are running selenium and your tests using docker-compose, you need to make sure to set the remote_url to the appropriate value, using the docker-compose created network http://hub:4444/wd/hub/. This currently isn’t supported by app config, so if using with the Wallaby.Feature module, you’ll need to pass it in as an option to start_session.

defmodule MyAppWeb.AFeatureTest do
  use ExUnit.Case
  use Wallaby.Feature
  
  @sessions [[remote_url: "http://hub:4444/wd/hub"]]
  feature "my test", %{session: session} do
    # ...
  end
end

Or, you can write your own ExUnit.CaseTemplate to start this in a setup, while using import Wallaby.Feature instead of use Wallaby.Feature. You can find an example of this at the bottom of this page: Wallaby.Feature — wallaby v0.31.0.

I apologize for just seeing this, but I recently set an alert on the wallaby tag. I should be notified of any further questions

Thanks for the clarification.

Can you advise please - is there any reason why Selenium driver might be preferred over Chrome driver?

You would want to use the selenium driver in order to test with Firefox, edge, or safari. Or if you’re using a hosted selenium service.

There is a crucial problem in this that you should change. The remote_url has to end in a trailing slash / or else it won’t work.

You can see this in webdriver_client.ex in the wallaby lib:

    request(:post, "#{base_url}session", params)

It just does bare string interpolation.

Good point to mention. That should be fixed. Thanks!

While I have your attention, I am getting a problem while trying to use Selenium (default driver works fine for me). I am using

    {:ok, session} = Wallaby.start_session(metadata: metadata, capabilities: chrome_capabilities, remote_url: "http://selenium-hub:4444/wd/hub/")

and I get this error:

* (RuntimeError) Content-Type header does not indicate utf-8 encoded json: application/json
     stacktrace:
       (wallaby 0.26.2) lib/wallaby/httpclient.ex:136: Wallaby.HTTPClient.check_for_response_errors/1
       (wallaby 0.26.2) lib/wallaby/httpclient.ex:56: Wallaby.HTTPClient.make_request/5
       (wallaby 0.26.2) lib/wallaby/selenium.ex:92: Wallaby.Selenium.start_session/1
       (wallaby 0.26.2) lib/wallaby.ex:83: Wallaby.start_session/1

Any ideas? No need to spend much time on it, just if you have any “hunch” of what might be happening.