Manual Validation for Prometheus metrics foundation with /metrics admin endpoint PR

Validation output are inline after the curl cmds

Start Praxis and a dummy endpoint:

cargo run -p praxis -- -c examples/configs/operations/admin-interface.yaml
python3 -m http.server 3000 both running.

Step 2: /metrics returns Prometheus text format

$ curl -si http://localhost:9901/metrics
HTTP/1.1 200 OK
Content-Type: text/plain; version=0.0.4; charset=utf-8
Date: Tue, 28 Apr 2026 05:06:20 GMT
Connection: keep-alive

# TYPE praxis_http_requests_total counter
praxis_http_requests_total{method="GET",status_class="4xx",route="unknown",cluster="backend"} 2
praxis_http_requests_total{method="HEAD",status_class="2xx",route="unknown",cluster="backend"} 2
praxis_http_requests_total{method="GET",status_class="2xx",route="unknown",cluster="backend"} 4
praxis_http_requests_total{method="POST",status_class="5xx",route="unknown",cluster="backend"} 2

# TYPE praxis_http_request_duration_seconds summary
praxis_http_request_duration_seconds{method="GET",status_class="2xx",route="unknown",cluster="backend",quantile="0"} 0
praxis_http_request_duration_seconds{method="GET",status_class="2xx",route="unknown",cluster="backend",quantile="0.5"} 0
praxis_http_request_duration_seconds{method="GET",status_class="2xx",route="unknown",cluster="backend",quantile="0.9"} 0
praxis_http_request_duration_seconds{method="GET",status_class="2xx",route="unknown",cluster="backend",quantile="0.95"} 0
praxis_http_request_duration_seconds{method="GET",status_class="2xx",route="unknown",cluster="backend",quantile="0.99"} 0
praxis_http_request_duration_seconds{method="GET",status_class="2xx",route="unknown",cluster="backend",quantile="0.999"} 0
praxis_http_request_duration_seconds{method="GET",status_class="2xx",route="unknown",cluster="backend",quantile="1"} 0
praxis_http_request_duration_seconds_sum{method="GET",status_class="2xx",route="unknown",cluster="backend"} 0.008274873
praxis_http_request_duration_seconds_count{method="GET",status_class="2xx",route="unknown",cluster="backend"} 4
praxis_http_request_duration_seconds{method="GET",status_class="4xx",route="unknown",cluster="backend",quantile="0"} 0
praxis_http_request_duration_seconds{method="GET",status_class="4xx",route="unknown",cluster="backend",quantile="0.5"} 0
praxis_http_request_duration_seconds{method="GET",status_class="4xx",route="unknown",cluster="backend",quantile="0.9"} 0
praxis_http_request_duration_seconds{method="GET",status_class="4xx",route="unknown",cluster="backend",quantile="0.95"} 0
praxis_http_request_duration_seconds{method="GET",status_class="4xx",route="unknown",cluster="backend",quantile="0.99"} 0
praxis_http_request_duration_seconds{method="GET",status_class="4xx",route="unknown",cluster="backend",quantile="0.999"} 0
praxis_http_request_duration_seconds{method="GET",status_class="4xx",route="unknown",cluster="backend",quantile="1"} 0
praxis_http_request_duration_seconds_sum{method="GET",status_class="4xx",route="unknown",cluster="backend"} 0.010357936
praxis_http_request_duration_seconds_count{method="GET",status_class="4xx",route="unknown",cluster="backend"} 2
praxis_http_request_duration_seconds{method="POST",status_class="5xx",route="unknown",cluster="backend",quantile="0"} 0
praxis_http_request_duration_seconds{method="POST",status_class="5xx",route="unknown",cluster="backend",quantile="0.5"} 0
praxis_http_request_duration_seconds{method="POST",status_class="5xx",route="unknown",cluster="backend",quantile="0.9"} 0
praxis_http_request_duration_seconds{method="POST",status_class="5xx",route="unknown",cluster="backend",quantile="0.95"} 0
praxis_http_request_duration_seconds{method="POST",status_class="5xx",route="unknown",cluster="backend",quantile="0.99"} 0
praxis_http_request_duration_seconds{method="POST",status_class="5xx",route="unknown",cluster="backend",quantile="0.999"} 0
praxis_http_request_duration_seconds{method="POST",status_class="5xx",route="unknown",cluster="backend",quantile="1"} 0
praxis_http_request_duration_seconds_sum{method="POST",status_class="5xx",route="unknown",cluster="backend"} 0.002428343
praxis_http_request_duration_seconds_count{method="POST",status_class="5xx",route="unknown",cluster="backend"} 2
praxis_http_request_duration_seconds{method="HEAD",status_class="2xx",route="unknown",cluster="backend",quantile="0"} 0
praxis_http_request_duration_seconds{method="HEAD",status_class="2xx",route="unknown",cluster="backend",quantile="0.5"} 0
praxis_http_request_duration_seconds{method="HEAD",status_class="2xx",route="unknown",cluster="backend",quantile="0.9"} 0
praxis_http_request_duration_seconds{method="HEAD",status_class="2xx",route="unknown",cluster="backend",quantile="0.95"} 0
praxis_http_request_duration_seconds{method="HEAD",status_class="2xx",route="unknown",cluster="backend",quantile="0.99"} 0
praxis_http_request_duration_seconds{method="HEAD",status_class="2xx",route="unknown",cluster="backend",quantile="0.999"} 0
praxis_http_request_duration_seconds{method="HEAD",status_class="2xx",route="unknown",cluster="backend",quantile="1"} 0
praxis_http_request_duration_seconds_sum{method="HEAD",status_class="2xx",route="unknown",cluster="backend"} 0.003298737
praxis_http_request_duration_seconds_count{method="HEAD",status_class="2xx",route="unknown",cluster="backend"} 2

Step 3: Existing admin endpoints still work

$ curl -si http://localhost:9901/healthy
HTTP/1.1 200 OK
Content-Type: application/json
Date: Tue, 28 Apr 2026 04:57:15 GMT
Connection: keep-alive


$ curl -si http://localhost:9901/ready
HTTP/1.1 200 OK
Content-Type: application/json
Date: Tue, 28 Apr 2026 04:57:15 GMT
Connection: keep-alive

{"status":"ok"}

Step 4: Request counter increments with traffic

$ curl -s http://localhost:8080/       # 2xx
$ curl -s http://localhost:8080/nonexistent  # 4xx

$ curl -s http://localhost:9901/metrics | grep praxis_http_requests_total
# TYPE praxis_http_requests_total counter
praxis_http_requests_total{method="GET",status_class="4xx",route="unknown",cluster="backend"} 2
praxis_http_requests_total{method="HEAD",status_class="2xx",route="unknown",cluster="backend"} 2
praxis_http_requests_total{method="GET",status_class="2xx",route="unknown",cluster="backend"} 4
praxis_http_requests_total{method="POST",status_class="5xx",route="unknown",cluster="backend"} 2

Step 5: Duration histogram appears with quantiles
$ curl -s http://localhost:9901/metrics | grep praxis_http_request_duration_seconds
# TYPE praxis_http_request_duration_seconds summary
praxis_http_request_duration_seconds{method="GET",status_class="2xx",route="unknown",cluster="backend",quantile="0"} 0
praxis_http_request_duration_seconds{method="GET",status_class="2xx",route="unknown",cluster="backend",quantile="0.5"} 0
praxis_http_request_duration_seconds{method="GET",status_class="2xx",route="unknown",cluster="backend",quantile="0.9"} 0
praxis_http_request_duration_seconds{method="GET",status_class="2xx",route="unknown",cluster="backend",quantile="0.95"} 0
praxis_http_request_duration_seconds{method="GET",status_class="2xx",route="unknown",cluster="backend",quantile="0.99"} 0
praxis_http_request_duration_seconds{method="GET",status_class="2xx",route="unknown",cluster="backend",quantile="0.999"} 0
praxis_http_request_duration_seconds{method="GET",status_class="2xx",route="unknown",cluster="backend",quantile="1"} 0
praxis_http_request_duration_seconds_sum{method="GET",status_class="2xx",route="unknown",cluster="backend"} 0.008274873
praxis_http_request_duration_seconds_count{method="GET",status_class="2xx",route="unknown",cluster="backend"} 4
praxis_http_request_duration_seconds{method="GET",status_class="4xx",route="unknown",cluster="backend",quantile="0"} 0
praxis_http_request_duration_seconds{method="GET",status_class="4xx",route="unknown",cluster="backend",quantile="0.5"} 0
praxis_http_request_duration_seconds{method="GET",status_class="4xx",route="unknown",cluster="backend",quantile="0.9"} 0
praxis_http_request_duration_seconds{method="GET",status_class="4xx",route="unknown",cluster="backend",quantile="0.95"} 0
praxis_http_request_duration_seconds{method="GET",status_class="4xx",route="unknown",cluster="backend",quantile="0.99"} 0
praxis_http_request_duration_seconds{method="GET",status_class="4xx",route="unknown",cluster="backend",quantile="0.999"} 0
praxis_http_request_duration_seconds{method="GET",status_class="4xx",route="unknown",cluster="backend",quantile="1"} 0
praxis_http_request_duration_seconds_sum{method="GET",status_class="4xx",route="unknown",cluster="backend"} 0.010357936
praxis_http_request_duration_seconds_count{method="GET",status_class="4xx",route="unknown",cluster="backend"} 2
praxis_http_request_duration_seconds{method="POST",status_class="5xx",route="unknown",cluster="backend",quantile="0"} 0
praxis_http_request_duration_seconds{method="POST",status_class="5xx",route="unknown",cluster="backend",quantile="0.5"} 0
praxis_http_request_duration_seconds{method="POST",status_class="5xx",route="unknown",cluster="backend",quantile="0.9"} 0
praxis_http_request_duration_seconds{method="POST",status_class="5xx",route="unknown",cluster="backend",quantile="0.95"} 0
praxis_http_request_duration_seconds{method="POST",status_class="5xx",route="unknown",cluster="backend",quantile="0.99"} 0
praxis_http_request_duration_seconds{method="POST",status_class="5xx",route="unknown",cluster="backend",quantile="0.999"} 0
praxis_http_request_duration_seconds{method="POST",status_class="5xx",route="unknown",cluster="backend",quantile="1"} 0
praxis_http_request_duration_seconds_sum{method="POST",status_class="5xx",route="unknown",cluster="backend"} 0.002428343
praxis_http_request_duration_seconds_count{method="POST",status_class="5xx",route="unknown",cluster="backend"} 2
praxis_http_request_duration_seconds{method="HEAD",status_class="2xx",route="unknown",cluster="backend",quantile="0"} 0
praxis_http_request_duration_seconds{method="HEAD",status_class="2xx",route="unknown",cluster="backend",quantile="0.5"} 0
praxis_http_request_duration_seconds{method="HEAD",status_class="2xx",route="unknown",cluster="backend",quantile="0.9"} 0
praxis_http_request_duration_seconds{method="HEAD",status_class="2xx",route="unknown",cluster="backend",quantile="0.95"} 0
praxis_http_request_duration_seconds{method="HEAD",status_class="2xx",route="unknown",cluster="backend",quantile="0.99"} 0
praxis_http_request_duration_seconds{method="HEAD",status_class="2xx",route="unknown",cluster="backend",quantile="0.999"} 0
praxis_http_request_duration_seconds{method="HEAD",status_class="2xx",route="unknown",cluster="backend",quantile="1"} 0
praxis_http_request_duration_seconds_sum{method="HEAD",status_class="2xx",route="unknown",cluster="backend"} 0.00161027
praxis_http_request_duration_seconds_count{method="HEAD",status_class="2xx",route="unknown",cluster="backend"} 1

Step 6: Separate label sets per HTTP method

$ curl -s -I http://localhost:8080/
HTTP/1.1 200 OK
Server: SimpleHTTP/0.6 Python/3.12.3
Date: Tue, 28 Apr 2026 05:03:28 GMT
Content-Type: text/html; charset=utf-8
Content-Length: 986
via: 1.1 praxis
Connection: keep-alive

$ curl -s http://localhost:9901/metrics | grep praxis_http_requests_total
# TYPE praxis_http_requests_total counter
praxis_http_requests_total{method="HEAD",status_class="2xx",route="unknown",cluster="backend"} 1
praxis_http_requests_total{method="GET",status_class="2xx",route="unknown",cluster="backend"} 4
praxis_http_requests_total{method="POST",status_class="5xx",route="unknown",cluster="backend"} 2
praxis_http_requests_total{method="GET",status_class="4xx",route="unknown",cluster="backend"} 2

Step 7: Unknown admin route returns 404
$ curl -si http://localhost:9901/nonexistent
HTTP/1.1 404 Not Found
Content-Type: application/json
Date: Tue, 28 Apr 2026 04:57:31 GMT
Connection: keep-alive

{"error":"not found"}

Step 8: No body-byte metrics present
$ curl -s http://localhost:9901/metrics | grep body_bytes
(no output — body_bytes metrics correctly absent)

Step 9: Cluster label preserved on 5xx
$ curl -s http://localhost:9901/metrics | grep 'status_class="5xx"'
praxis_http_requests_total{method="POST",status_class="5xx",route="unknown",cluster="backend"} 2
praxis_http_request_duration_seconds{method="POST",status_class="5xx",route="unknown",cluster="backend",quantile="0"} 0
praxis_http_request_duration_seconds{method="POST",status_class="5xx",route="unknown",cluster="backend",quantile="0.5"} 0
praxis_http_request_duration_seconds{method="POST",status_class="5xx",route="unknown",cluster="backend",quantile="0.9"} 0
praxis_http_request_duration_seconds{method="POST",status_class="5xx",route="unknown",cluster="backend",quantile="0.95"} 0
praxis_http_request_duration_seconds{method="POST",status_class="5xx",route="unknown",cluster="backend",quantile="0.99"} 0
praxis_http_request_duration_seconds{method="POST",status_class="5xx",route="unknown",cluster="backend",quantile="0.999"} 0
praxis_http_request_duration_seconds{method="POST",status_class="5xx",route="unknown",cluster="backend",quantile="1"} 0
praxis_http_request_duration_seconds_sum{method="POST",status_class="5xx",route="unknown",cluster="backend"} 0.002428343
praxis_http_request_duration_seconds_count{method="POST",status_class="5xx",route="unknown",cluster="backend"} 2