Running selenium tests using Behat Drupal Extension inside DDEV containers - selenium

Question

Problem: Get Behat Drupal Extension based testing working inside of ddev containers. This includes adding a separate selenium container to the existing configuration, being able to run Behat tests, and having the be able to reference the web host container.

Answer 1

Prerequisites: have a working ddev instance hosting Drupal. There are examples already to set that up, so I won't repeat that here.
The above task required the following additions:
selenium container: The container running selenium. I used the chrome standalone version. Add the following to your .ddev folder:
File: docker-compose.selenium.yml
version: '3.6'
services:
selenium:
container_name: ddev-${DDEV_SITENAME}-selenium
image: selenium/standalone-chrome-debug:3.13.0-argon
networks:
default:
aliases:
- web
The last bit is critical; the selenium container needs to know about the web container running the drupal instance to connect to it, but as it is a dependency of the web container, you can't use 'links'. You have to use the aliases approach, using the default network.
compose override: A file overriding the defaults for the web container to link the selenium container to it.
File: docker-compose.override.yml
version: '3.6'
services:
web:
depends_on:
- db
- selenium
links:
- db:db
- selenium:selenium
Behat configuration: The following Behat configuration for MinkExtension worked for me:
(modify file behat.yml)
default:
extensions:
"Behat\\MinkExtension":
goutte: null
base_url: 'http://web'
javascript_session: selenium2
selenium2:
browser: "chrome"
wd_host: http://selenium:4444/wd/hub
capabilities:
extra_capabilities:
idle-timeout: 50
base_url and wd_host entries were critical in getting this to work.
For more information on the last, see step 5 in the Behat Drupal Extension docs:
Configure your testing environment by creating a file called behat.yml with the following. Be sure that you point the base_url at the web site YOU intend to test. Do not include a trailing slash:
default:
suites:
default:
contexts:
- FeatureContext
- Drupal\DrupalExtension\Context\DrupalContext
- Drupal\DrupalExtension\Context\MinkContext
- Drupal\DrupalExtension\Context\MessageContext
- Drupal\DrupalExtension\Context\DrushContext
extensions:
Drupal\MinkExtension:
goutte: ~
selenium2: ~
base_url: http://seven.l
Drupal\DrupalExtension:
blackbox: ~