The default runtime for the Krustlet project is wasi.

The wasi runtime uses a project called wasmtime. wasmtime is a standalone JIT-style host runtime for WebAssembly modules. It is focused primarily on standards compliance with the WASM specification as it relates to WASI. If your WebAssembly module complies with the WebAssembly specification, wasmtime can run it.

It’s important to note that the WASI standard and wasmtime are still under heavy development. There are some key features (like networking) that are currently missing, but will be made available in future updates.

Additional Providers

There are various other providers available as well.

  • wasmcloud: The wasmcloud runtime is a secure WebAssembly host runtime, connecting “actors” and “capability providers” together to connect your WebAssembly runtime to cloud-native services like message brokers, databases, or other external services normally unavailable to the WebAssembly runtime. This provider used to be available in this repo but was moved under the wasmCloud project so it could be maintained both by the Krustlet maintainers and the wasmCloud maintainers.
  • CRI: A Container Runtime Interface provider implementation for Krustlet. This runtime allows you to run the containers you know and love within Krustlet.