kuasar VS gvisor

Right now most early examples alas boot a container with a wasm runtime for each wasm instance, which is a sad waste. The whole advantage of wasm should be very lightweight low overhead wasm runtime instances atop a common wasm process. Having a process or container for each instance loses a ton of the benefit, makes it not much better than a regular container.

Thankfully there is work like the Containerd Sandbox API which enables new architectures like this. https://github.com/containerd/containerd/issues/4131

It's still being used to spawn a wasm processes per instance for now, but container runtime project Kuasar is already using the Sandbox API to save significant resources, and has already chimed in in comments on HN to express a desire to have shared-process/multi-wasm-instamxe runtimes, which could indeed allow sub ms spawning that could enable instance per request architectures. https://github.com/kuasar-io/kuasar

Isn't gVisor kind of this as well?

"gVisor is an application kernel for containers. It limits the host kernel surface accessible to the application while still giving the application access to all the features it expects. Unlike most kernels, gVisor does not assume or require a fixed set of physical resources; instead, it leverages existing host kernel functionality and runs as a normal process. In other words, gVisor implements Linux by way of Linux."

https://github.com/google/gvisor

This sort of feels like seeing someone riding a bike and saying: why don’t they just get a car? The simple fact is that containers and VMs are quite different. Whether something uses VMX and friends or not is also a red herring, as gVisor also “rolls it own VMM” [1].

[1] https://github.com/google/gvisor/tree/master/pkg/sentry/plat...

There's two major production-ready Go-based operating system(-ish) projects:

- Google's gVisor[1] (a re-implementation of a significant subset of the Linux syscall ABI for isolation, also mentioned in the article)

- USBArmory's Tamago[2] (a single-threaded bare-metal Go runtime for SOCs)

Both of these are security-focused with a clear trade off: sacrifice some performance for memory safe and excellent readability (and auditability). I feel like that's the sweet spot for low-level Go - projects that need memory safety but would rather trade some performance for simplicity.

[1]: https://github.com/google/gvisor

[2]: https://github.com/usbarmory/tamago

It uses gVisor to create a TCP/IP stack in userspace, and starts a wireguard interface on it, which the HTTP server from http.Serve listens on. The library will print a URL after startup, where you can access your server. You can create multiple listeners in one binary.

The playground compiles the program with GOOS=linux, GOARCH=amd64 and runs the program with gVisor. Detailed documentation is available at the gVisor site.

You could use a container sandbox like gVisor, light virtual machines as containers (Kata containers, firecracker + containerd) or full virtual machines (virtlet as a CRI).