Browser Performance Testing with the Sitespeed.io container

This example shows how to run the Sitespeed.io container on your code by using GitLab CI/CD and Sitespeed.io using Docker-in-Docker.

First, you need a GitLab Runner with the docker-in-docker executor. Once you set up the Runner, add a new job to .gitlab-ci.yml, called performance:

performance:
  stage: performance
  image: docker:git
  variables:
    URL: https://example.com
  services:
    - docker:stable-dind
  script:
    - mkdir gitlab-exporter
    - wget -O ./gitlab-exporter/index.js https://gitlab.com/gitlab-org/gl-performance/raw/master/index.js
    - mkdir sitespeed-results
    - docker run --shm-size=1g --rm -v "$(pwd)":/sitespeed.io sitespeedio/sitespeed.io:6.3.1 --plugins.add ./gitlab-exporter --outputFolder sitespeed-results $URL
    - mv sitespeed-results/data/performance.json performance.json
  artifacts:
    paths:
    - performance.json
    - sitespeed-results/

The above example will:

1. Create a performance job in your CI/CD pipeline and will run Sitespeed.io against the webpage you defined in URL.
2. The GitLab plugin for Sitespeed.io is downloaded in order to export key metrics to JSON. The full HTML Sitespeed.io report will also be saved as an artifact, and if you have GitLab Pages enabled, it can be viewed directly in your browser.

For further customization options of Sitespeed.io, including the ability to provide a list of URLs to test, please consult their documentation.

TIP: Tip: For GitLab Premium users, key metrics are automatically extracted and shown right in the merge request widget. Learn more about Browser Performance Testing.

Performance testing on Review Apps

The above CI YML is great for testing against static environments, and it can be extended for dynamic environments. There are a few extra steps to take to set this up:

1. The performance job should run after the dynamic environment has started.
2. In the review job, persist the hostname and upload it as an artifact so it's available to the performance job (the same can be done for static environments like staging and production to unify the code path). Saving it as an artifact is as simple as echo $CI_ENVIRONMENT_URL > environment_url.txt in your job's script.
3. In the performance job, read the previous artifact into an environment variable, like $CI_ENVIRONMENT_URL, and use it to parameterize the test URLs.
4. You can now run the Sitespeed.io container against the desired hostname and paths.

Your .gitlab-ci.yml file would look like:

stages:
  - deploy
  - performance

review:
  stage: deploy
  environment:
    name: review/$CI_COMMIT_REF_SLUG
    url: http://$CI_COMMIT_REF_SLUG.$APPS_DOMAIN
  script:
    - run_deploy_script
    - echo $CI_ENVIRONMENT_URL > environment_url.txt
  artifacts:
    paths:
      - environment_url.txt
  only:
    - branches
  except:
    - master

performance:
  stage: performance
  image: docker:git
  services:
    - docker:stable-dind
  dependencies:
    - review
  script:
    - export CI_ENVIRONMENT_URL=$(cat environment_url.txt)
    - mkdir gitlab-exporter
    - wget -O ./gitlab-exporter/index.js https://gitlab.com/gitlab-org/gl-performance/raw/master/index.js
    - mkdir sitespeed-results
    - docker run --shm-size=1g --rm -v "$(pwd)":/sitespeed.io sitespeedio/sitespeed.io:6.3.1 --plugins.add ./gitlab-exporter --outputFolder sitespeed-results "$CI_ENVIRONMENT_URL"
    - mv sitespeed-results/data/performance.json performance.json
  artifacts:
    paths:
      - performance.json
      - sitespeed-results/

A complete example can be found in our Auto DevOps CI YML.