Bypass Container Overlay Networks with Transparent BPF-driven Socket Replacement
Containerization on the cloud offers several crucial benefits. However, these benefits are negated by the effects of virtual network stack and address encapsulation, especially for workloads that require intense communication. Socket replacement is a promising approach to breach this wall without changing the underlay infrastructure by replacing a nested network stack with a simple host network stack. Current state-of-the-art approaches perform this replacement by preloading the overridden socket library in a containerized process. However, the preloading approach requires user effort to modify the deploying manifests and a compromised security policy configuration of privileged containers to access the host namespace. This paper introduces a new replacement framework where a secured control plane agent performs the replacement by utilizing low-overhead BPF kernel tracing technology. As a result, containers can obtain host-native network performance and neither modification nor escalated privileges are required for user containers. Experiments on multiple benchmarks including iPerf, MPI, memslap, and GROMACS have been conducted to confirm efficacy.