dependencies: pre: npm install -g sitespeed.io
And something like this test. Craft the URI to meet your testing environment, browser types, and number of test iterations to meet your needs.
test: override: - sitespeed.io -u http://SITE.LOCAL --budget cnf/sitespeed/budget.json -b chrome -n 3 -r $CIRCLE_ARTIFACTS/sitespeed --suppressDomainFolder --outputFolderName test
The test specifies performance budget file which sets the performance requirements. You can tune the specifications in this file for the characteristics that you're looking for- first paint time, final render time, etc. Your test results are put into the artifacts directory so you can browse them at some later point- here's where the artifacts are in the circle build:
And here's an actual report which has been run as part of the CircleCi build.
Arguably the hardest part of this process is building the performance budget file which is tailored to your needs, particularly since running them on a CI server is going to have a different profile than your production environment.