Wasm Intro

Rainer Stropek | @rstropek

Material

• These slides 🔗
• Client-side sample 🔗
• Server-side sample 🔗

What is WebAssembly (Wasm)

• Binary instruction format
  • Open specification 🔗
• Stack-based VM
• Portable compilation target
• Deployable on (web) client and servers
• Sandboxed execution environment
  • Security policies of the browsers are enforced
  • When embedded in JS runtime, interact with JS

Rust and Wasm

• Use cases on the client
  • Build part of an application
    • Reuse existing code (e.g. rendering logic)
    • Implement CPU-intensive, performance-critical parts
  • Build an entire web application
    • E.g. yew 🔗
• Use cases on the server
  • Build part of an application (e.g. in combination with Node.js)
  • Build web apps/APIs
    • ​E.g. WAGI  🔗, Spin 🔗
    • Similar to Container technology

What is WASI?

• WebAssembly System Interface
• Not focusing on web apps, but server apps
  • Yet, it can run in a web-browser
• Standard set of APIs to interact with OS
  • E.g. file access, networking
  • Portable, not OS-specific

Wasmtime, Wasmer, Krustlet & Co

• Runtimes for WebAssembly and WASI
  • Wasmtime 🔗
  • Wasmer 🔗
• Wasm in K8s
  • Krustlet 🔗