Что такое WASI
WASI (WebAssembly System Interface) — standard API для WebAssembly вне браузера. Даёт WASM access to filesystem, network, env vars в sandboxed way. Enables server-side WASM: Fastly Compute@Edge, Fermyon Spin, Docker WASM containers, Envoy WASM filters. Сompetes с containers для lightweight serverless. Runtimes: Wasmtime (Mozilla), WasmEdge, WasmCloud.
Ниже: подробности, пример, смежные термины, FAQ.
Подробности
- WASI Preview 1: basic POSIX-like interface (deprecated — 2019)
- WASI Preview 2 (2024 stable): component model, world interfaces
- Sandboxing: capability-based security (explicit file/net access)
- Start time: 1-5 ms vs container 100ms+ vs JVM 1s+
- Languages: Rust, C/C++, Go, Python, TinyGo all compile to WASI
Пример
// Rust → WASI
// Cargo.toml
[dependencies]
wasi = "0.13"
// main.rs
use std::fs;
fn main() {
let content = fs::read_to_string("/data/input.txt").unwrap();
println!("{}", content);
}
// Build: cargo build --target wasm32-wasi
// Run: wasmtime --dir=/host/data main.wasmСмежные термины
Больше по теме
Часто задаваемые вопросы
WASI vs containers?
WASI: much faster start, smaller (KB vs MB), language-neutral. Containers: больше compatibility с existing software. Для serverless/edge — WASI win.
Когда production-ready?
Preview 2 released 2024 stable. Fastly, Cloudflare Workers используют внутри. Для mainstream — 2026+.
Замена containers?
Не замена, а complement. Containers сохранятся для legacy apps. Новые edge functions, plugins, serverless — WASI.