Technology · Ebook

Kuasar: A Multi-Sandbox Container Runtime

by Shriira Press

Kuasar is a low-level, Rust-based container runtime, open-sourced by Huawei and now a CNCF sandbox project, that answers a question older runtimes dodged: what if one node needed several isolation technologies at once? A plain container, a hardware-isolated microVM, a WebAssembly module, and an app-kernel sandbox each suit different workloads, yet earlier runtimes forced them through a model built for Linux containers. Kuasar rebuilds the runtime around the containerd Sandbox API, treating the sandbox as a first-class citizen and replacing per-container shims with a single resident sandboxer. This book moves from the problem and ecosystem context, through Kuasar's architecture and each sandboxer — microVM, Wasm, app-kernel, and runc — to its containerd integration and how teams run it in practice.

Contents

1. 1Preface
2. 2Chapter 1 — What Kuasar Is
3. 3Chapter 2 — The Sandbox API and the Shim Problem
4. 4Chapter 3 — Architecture: Sandboxer and Task
5. 5Chapter 4 — The MicroVM Sandboxer
6. 6Chapter 5 — Wasm and App-Kernel Sandboxers
7. 7Chapter 6 — Integrating with containerd
8. 8Chapter 7 — Kuasar in Practice