Wellingtone Luvonga details a practical guide to shifting Kubernetes from default-allow to explicit microsegmentation using NetworkPolicies. The approach focuses on securing a three-tier architecture by enforcing strict ingress and egress rules via label-driven policies. Calico CNI is utilized to actually intercept and enforce these restrictions on standard Kubernetes API objects.
- Shift from default-allow to explicit, label-driven microsegmentation for zero-trust.
- Secure three-tier apps (Frontend, Backend, DB) with specific ingress/egress rules.
- Kubernetes API objects define intent; the CNI (Calico) enforces the actual traffic blocking.
- Validate restrictions by testing traffic flow between tiers in a dedicated namespace.