The Kubernetes network model read from the room up — why a Pod gets one IP and shares it across containers, the three rules every CNI must satisfy and where NAT still lives, how a Pod IP is born in two steps and dies only with the Pod, what kubelet actually does when it probes, and the /24-vs-/32 choice that decides whether the host sees every packet.
Isolating other people’s code on a shared EKS hosting cluster — why gVisor over plain containers, Fargate or per-team nodes, why Cilium replaces the default VPC CNI while the cluster is still empty, how the node bootstrap installs a pinned and checksummed gVisor that fails closed, the missing gvisor-bin directory that broke the first apply, and the app domain and __Host- cookie that keep user apps away from the dashboard.
How a container’s room gets out — Docker’s network modes compared with real namespace numbers, inside/outside pairing by @ifN, docker0 joined to the NIC by routing and NAT, CNM vs CNI and one CNI plugin call, VXLAN overlay, and one Go server knocked on from four places: another container, the host, another machine, and a container sharing its room.
Ambassador 패턴은 왜 요즘 잘 안 쓰일까 — 사이드카의 한계에서 출발해 Sidecarless 메시, CNI의 실체, eBPF까지. 하는 일은 그대로인데 프록시의 근무지만 이사 중이라는 이야기.
eBPF 로 Pod 네트워크와 네트워크 정책, 서비스 로드 밸런싱, 통신 관측을 처리하는 CNI 플러그인. Hubble 로 누가 어디로 통신했고 왜 막혔는지 기록한다.
컨테이너가 만들어질 때 네트워크를 붙이는 방법을 정한 규격. 런타임이 플러그인 실행 파일을 부르고, 플러그인이 Pod 안에 인터페이스와 IP·경로를 만든다.