Kong: the prometheus plugin exposes metrics on the status port

curl -X POST http://localhost:8001/plugins \
  --data name=prometheus \
  --data config.status_code_metrics=true \
  --data config.latency_metrics=true \
  --data config.upstream_health_metrics=true

curl http://localhost:8100/metrics

kong_http_requests_total{service="billing",code="200"} 48210
kong_request_latency_ms_bucket{service="billing",le="100"} 47990
kong_upstream_target_health{upstream="billing-upstream",state="healthy"} 1
kong_nginx_connections_total{state="active"} 42

# Per-consumer metrics are off by default and are the ones that explode
# cardinality - one time series per consumer per service per status code.