| Identified misleading symptom |
Tested cross-namespace connectivity on both ports; identified NetworkPolicy as the blocker within 10 min |
Noticed the metrics port was blocked but took time to find the NetworkPolicy |
Investigated Grafana data sources or Prometheus configuration extensively |
| Found root cause in kubernetes domain |
Found the default-deny NetworkPolicy and the missing port 9090 allow rule |
Found the NetworkPolicy but not the missing port detail |
Assumed the services stopped exporting metrics |
| Remediated in networking domain |
Created a targeted NetworkPolicy allowing Prometheus scrapes from monitoring namespace, plus DNS egress |
Added a broad allow rule that fixed the issue but was overly permissive |
Changed Prometheus configuration or service annotations instead |
| Cross-domain thinking |
Explained the tension between security hardening and observability; proposed standard templates |
Acknowledged NetworkPolicy broke metrics but did not propose prevention |
Treated it as a single-domain observability or Kubernetes issue |