On today’s podcast, Justin Cormack discusses how the modern operating system is being decomposed with toolkits and libraries such as LinuxKit, eBPF, XDP, and what the kernel space service mesh Cilium is doing. Wes Reisz and Justin Cormack also discuss how Cilium differs from service meshes like an Istio, Linkerd2 (previously Conduit), or Envoy. Justin is a systems engineer at Docker. He previously was working with unikernels at Unikernel Systems in Cambridge before being acquired by Docker. (edited)

*Key Takeaways:*

* LinuxKit is an appliance way of thinking about your operating system and is gaining adoption. There are contributions now from Oracle, Cloudflare, Intel, etc. Docker has seen interesting use cases such as customers running LinuxKit on large cloud providers directly on bare metal (more on this coming soon).

* The operating system of today is really unchanged since the Sun workstation of the 90’s. Yet everything else about software has really changed such as automation, build pipelines, and delivery.

* XDP (eXpress Data Path) is a packet processing layer for Linux that lets you run fast in kernel compiled safe program in kernel called eBPF. It’s used for things like packet filtering and encapsulation/decapsulation.

* Cilium is an in-kernel, high performance service mesh that leverages eBPF. Cilium is very good at layer 4 processing, but doesn’t really do the layer 7 things that some of the other services meshes can offer (such as proxying http/1 to http/2)