Kubernetes Network Policies: Lessons from Production Incidents

Short summary

A practical guide to Kubernetes Network Policies based on real production incidents, covering default-deny strategies, DNS egress requirements, metrics scraping gaps, and external API call failures. Includes concrete YAML examples for namespace-level and pod-level policies, CNI compatibility notes, and a recommended progression from coarse namespace-level rules to tighter pod-level restrictions for sensitive services.

• •Default-deny network policies break DNS, metrics, and external calls — plan for it
• •Three real incident case studies: DNS failure, Prometheus scraping gap, Stripe API blocked
• •Start with namespace-level policies, tighten to pod-level for sensitive services

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