[TP] Final Lab: Blocking performance test in continuous integration

What you will learn in this TP
Write a smoke test for CI
Create the workflow
Observe a blocked pull request

Introduction #

What you will learn in this section
Write a smoke test for CI
Create the workflow
Observe a blocked pull request

Context. A performance regression reached production last month. From now on, no pull request may degrade latency beyond the SLO.

Prerequisites: GitHub account, test repository · Estimated time: 40 min

Performance tested on every change.

Guided steps, with their solutions.

1. Prepare the repository
Why? The test lives next to the code it protects.
In a repository, create docker-compose.yml (httpbin on port 8080) and tests/perf/smoke.js (10 VUs, 30 s, thresholds p95 < 300 ms and failures < 1%) targeting http://localhost:8080/get.
2. Write the workflow
Why? The official actions install k6 and run the script; an unmet threshold fails the job.
Create .github/workflows/perf.yml, triggered on pull requests.
3. Open a healthy pull request
Why? To check the nominal path.
Push to a branch and open a pull request: the job should succeed.
4. Simulate a regression
Why? Proof that the safeguard works.
Change the tested route to /delay/1 (simulating slower code), push and observe the result.

Difficulty level : ●●●○○ (3/5)

My progress

⏱ Estimated time : ≈ 40 min

No questions yet: be the first to ask for help or share your configuration.