Merge branch 'enable-perf-in-mr' into 'master'

Enabling performance metrics on Review Apps

Closes #57881

See merge request gitlab-org/gitlab-ce!25549

.gitlab-ci.yml

@@ -1045,6 +1045,20 @@ review-qa-all:
     - gitlab-qa Test::Instance::Any "${QA_IMAGE}" "${CI_ENVIRONMENT_URL}"
   when: manual
 
+review-performance:
+  <<: *review-qa-base
+  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 "$(pwd)":/sitespeed.io sitespeedio/sitespeed.io:6.3.1 --plugins.add ./gitlab-exporter --outputFolder sitespeed-results "$CI_ENVIRONMENT_URL"
+    - mv sitespeed-results/data/performance.json performance.json
+  artifacts:
+    paths:
+      - sitespeed-results/
+    reports:
+      performance: performance.json
+
 review-stop:
   <<: *review-base
   <<: *single-script-job

doc/development/testing_guide/review_apps.md

@@ -95,6 +95,14 @@ You can also manually start the `review-qa-all`: it runs the full QA suite.
 
 Note that both jobs first wait for the `review-deploy` job to be finished.
 
+## Performance Metrics
+
+On every [pipeline][gitlab-pipeline] during the `test` stage, the
+`review-performance` job is automatically started: this job does basic
+browser performance testing using [Sitespeed.io Container](https://docs.gitlab.com/ee/user/project/merge_requests/browser_performance_testing.html) .
+
+This job waits for the `review-deploy` job to be finished.
+
 ## How to?
 
 ### Log into my Review App?