Add Grafana K6 performance test scripts for all 5 microservices

[devin-ai-integration]

Summary

Adds Grafana K6 performance test scripts for all 5 microservices (Identity, Customer, Order, Product, Notification) plus a combined all-services test that runs 10 VUs across all services simultaneously.

Files added (k6-tests/)

File	Purpose
config.js	Shared config — service URLs, __ENV mapping, default stages & thresholds
utils.js	Auth helpers (Bearer + Basic), check() wrappers for GET/POST
data/*.json	20 production-realistic records per service for data-driven testing via SharedArray
identity-test.js	GET /api/identity, GET /api/identity/{id}
customer-test.js	GET /api/customer, GET /api/customer/{id}
order-test.js	GET /api/order, GET /api/order/{id}
product-test.js	GET /api/product, GET /api/product/{id}
notification-test.js	GET (paginated), GET by ID, GET preview, POST /events/order-placed
all-services-test.js	Combined test — 10 VUs (2 per service), 25 iterations each, ~5 min with pacing

Combined test results (actual run)

All 250 iterations completed, 1750/1750 checks passed (100%), all thresholds met:

Service	Requests	Avg	Med	p95	Max
Identity	100	2.10ms	0.98ms	1.77ms	47ms
Customer	100	1.86ms	0.95ms	3.85ms	39.76ms
Order	100	1.94ms	0.99ms	1.98ms	32.46ms
Product	100	2.03ms	1.02ms	2.15ms	30.38ms
Notification	200	8.41ms	2.49ms	7.35ms	408.93ms
Overall	601	4.14ms	1.24ms	6.25ms	408.93ms

Error rate: 0.16% (1/601) — within the 5% threshold.

Bug fix included

Fixed Notification.API.csproj — Shared project reference paths were ../../Shared/ but needed ../../../Shared/ (three levels up from Services/Notification/Notification.API/).

Review & Testing Checklist for Human

• Run docker compose up --build and execute k6 run k6-tests/all-services-test.js to verify end-to-end
• Review threshold values in config.js / all-services-test.js for your target SLAs
• Verify the Notification.API.csproj path fix doesn't break your local IDE or CI build

Notes

• The combined test uses per-vu-iterations executor for precise control: exactly 2 VUs × 25 iterations = 50 requests per service
• Pacing (~10s ± 3s jitter between iterations) spreads load realistically across the 5-minute window
• Each iteration picks different data records (20 per service) to avoid cache hits and emulate production variance

Link to Devin session: https://partner-workshops.devinenterprise.com/sessions/c2a7605ddb284e07a746fbc9eabb5eac
Requested by: @vinodsvv

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[devin-ai-integration]

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[devin-ai-integration]

Devin Review found 1 potential issue.

View 5 additional findings in Devin Review.

[devin-ai-integration]

🟡 Notification test setup() missing basic auth fallback, unlike default function

In notification-test.js, the setup() function constructs headers manually (lines 53-55) and sends the seed POST request without any Authorization header when fetchBearerToken() returns null. However, the default function (lines 82-84) correctly falls back to basicAuthHeaders() when no token is available. This inconsistency means the seed request goes out unauthenticated while all other requests use Basic auth. If the service (or API Gateway) requires authentication but the token endpoint is unavailable, the seed request will fail with 401, leaving seededId as null. This silently causes Groups 3 and 4 ("Get By ID" and "Preview") to be skipped entirely (line 158), so half the notification test coverage is lost without any test failure or warning.

Suggested change

	const headers = token
	? { 'Content-Type': 'application/json', Accept: 'application/json', Authorization: `Bearer ${token}` }
	: { 'Content-Type': 'application/json', Accept: 'application/json' };
	const headers = token
	? { 'Content-Type': 'application/json', Accept: 'application/json', Authorization: `Bearer ${token}` }
	: basicAuthHeaders();

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