Container Runtime Security with eBPF and Cilium

Kubernetes network policies aren’t enough. We need to see inside containers — what processes are running, where they communicate, what files they open. eBPF makes this possible without a performance penalty.

What Is eBPF?¶

eBPF (extended Berkeley Packet Filter) is a Linux kernel technology that allows running sandboxed code safely — without modifying the kernel. Observability, networking, and security — all at the kernel level.

Cilium for Network Security¶

Cilium replaced kube-proxy and Calico in our cluster. L7-aware network policies (HTTP, gRPC, Kafka), transparent encryption, and detailed flow visibility. Policy: “service A may call service B only on endpoint /api/v1/orders using the GET method.”

Falco for Runtime Detection¶

Falco (CNCF) monitors syscalls in containers using eBPF. Rules: shell spawned in a container = alert, reading /etc/shadow = alert, unexpected outbound connection = alert. Integration with PagerDuty.

eBPF Is Changing Container Security¶

Kernel-level visibility without overhead. Cilium + Falco = networking and runtime security in one place.