How to run Selenium Grid 4 network in GitLab CI? - selenium

Question

I want to run selenum grid containers in GitLab. They would be: one selenium hub and two chrome node containers connected by a shared network. I know how to deploy those using a yaml file, but I have no idea how to start those containers in gitlab.
Ideally, the 3 cotainers would be started in pipleine, and then I would execute a script that would run some Selenium tests using the grid.
There's my yml file that would start selenium grid locally:
version: '3.7'
services:
selenium-1:
image: selenium/node-chrome:latest
shm_size: '2gb'
depends_on:
- selenium-hub
environment:
- SE_EVENT_BUS_HOST=selenium-hub
- SE_EVENT_BUS_PUBLISH_PORT=4442
- SE_EVENT_BUS_SUBSCRIBE_PORT=4443
selenium-2:
image: selenium/node-chrome:latest
shm_size: '2gb'
depends_on:
- selenium-hub
environment:
- SE_EVENT_BUS_HOST=selenium-hub
- SE_EVENT_BUS_PUBLISH_PORT=4442
- SE_EVENT_BUS_SUBSCRIBE_PORT=4443
selenium-hub:
image: selenium/hub:latest
expose:
- 4444
There's the script that would start the selenium tests:
#!/usr/bin/env bash
set -e
python -m pytest
The .gitlab-ci.yml I have so far:
stages:
- e2e
e2e:
stage: e2e
interruptible: false
services:
- selenium/hub:latest
- selenium/node-chrome:latest
script:
- bash run_test_page.sh

Answer 1

i basically use dind to run the compose file.
in the snippets below, i am trying to mention the essential bits, you can see a full project example here
also, i am using java and maven, not much change should be needed for python in your case
docker-compose used by the gitlab pipeline -
version: "3"
services:
selenium-chrome-01: &selenium-chrome
image: selenium/node-chrome:4.3.0-20220726
shm_size: 2gb
depends_on:
- selenium-hub
environment:
SE_EVENT_BUS_HOST: ${SELENIUM_SERVER_NAME}
SE_EVENT_BUS_PUBLISH_PORT: 4442
SE_EVENT_BUS_SUBSCRIBE_PORT: 4443
selenium-chrome-02:
<<: *selenium-chrome
selenium-hub:
image: selenium/hub:4.3.0-20220726
shm_size: 2gb
container_name: ${SELENIUM_SERVER_NAME}
ping:
image: alpine/curl
tests:
image: openjdk:11
working_dir: /app
volumes:
- ${CI_PROJECT_DIR}:/app
environment:
ENVIRONMENT: remote
SELENIUM_SERVER_URL: ${SELENIUM_SERVER_URL}
the compose file has 4 containers - 2 worker nodes, 1 hub, 1 to check the status of the hub, and 1 to run the tests
gitlab pipeline file -
stages:
- test
variables:
SELENIUM_SERVER_NAME: selenium
SELENIUM_SERVER_URL: http://${SELENIUM_SERVER_NAME}:4444
DOCKER_HOST: tcp://docker:2375
services:
- docker:20.10.16-dind
test:
stage: test
image: docker/compose
before_script:
- docker-compose up -d selenium-hub selenium-chrome-01 selenium-chrome-02
- sleep 10
- docker-compose run ping curl ${SELENIUM_SERVER_URL}/status
script:
- docker-compose run tests ./mvnw test -Dtest=TestClass
i think if you can configure shm_size on the gitlab runner's config, you can run the selenium grid as services which i feel is a better solution