WebAssembly 容器

const bytes = Uint8Array.from([
  0x00, 0x61, 0x73, 0x6d, 0x01, 0x00, 0x00, 0x00,
  0x01, 0x05, 0x01, 0x60, 0x01, 0x7f, 0x00,
  0x02, 0x0e, 0x01, 0x04, 0x68, 0x6f, 0x73, 0x74,
  0x05, 0x61, 0x75, 0x64, 0x69, 0x74, 0x00, 0x00,
  0x03, 0x02, 0x01, 0x00,
  0x07, 0x07, 0x01, 0x03, 0x72, 0x75, 0x6e, 0x00,
  0x01,
  0x0a, 0x08, 0x01, 0x06, 0x00, 0x20, 0x00, 0x10,
  0x00, 0x0b,
]);

const module = await WebAssembly.compile(bytes);
const required = WebAssembly.Module.imports(module)[0];
console.log(`requires: ${required.module}.${required.name} (${required.kind})`);

try {
  await WebAssembly.instantiate(module, {});
} catch (error) {
  console.log(`without grant: ${error.name}`);
}

const imports = { host: { audit: value => console.log(`audit: ${value}`) } };
const instance = await WebAssembly.instantiate(module, imports);
instance.exports.run(7);

import { createHash } from "node:crypto";
import { mkdir, writeFile } from "node:fs/promises";

const root = "double-oci";
const wasm = Buffer.from([
  0x00, 0x61, 0x73, 0x6d, 0x01, 0x00, 0x00, 0x00,
  0x01, 0x06, 0x01, 0x60, 0x01, 0x7f, 0x01, 0x7f,
  0x03, 0x02, 0x01, 0x00,
  0x07, 0x0a, 0x01, 0x06, 0x64, 0x6f, 0x75, 0x62,
  0x6c, 0x65, 0x00, 0x00,
  0x0a, 0x09, 0x01, 0x07, 0x00, 0x20, 0x00, 0x41,
  0x02, 0x6c, 0x0b,
]);
const encode = value => Buffer.from(JSON.stringify(value));
const digest = data => `sha256:${createHash("sha256").update(data).digest("hex")}`;
const descriptor = (mediaType, data) => ({ mediaType, digest: digest(data), size: data.length });

await mkdir(`${root}/blobs/sha256`, { recursive: true });
const put = async data => writeFile(`${root}/blobs/sha256/${digest(data).slice(7)}`, data);
const layer = descriptor("application/wasm", wasm);
const configBytes = encode({ architecture: "wasm", os: "wasip1", layerDigests: [layer.digest] });
const config = descriptor("application/vnd.wasm.config.v0+json", configBytes);
const manifestBytes = encode({
  schemaVersion: 2,
  mediaType: "application/vnd.oci.image.manifest.v1+json",
  config,
  layers: [layer],
});
const manifest = descriptor("application/vnd.oci.image.manifest.v1+json", manifestBytes);
manifest.annotations = { "org.opencontainers.image.ref.name": "double:v1" };

await Promise.all([put(wasm), put(configBytes), put(manifestBytes)]);
await writeFile(`${root}/oci-layout`, encode({ imageLayoutVersion: "1.0.0" }));
await writeFile(`${root}/index.json`, encode({ schemaVersion: 2, manifests: [manifest] }));

console.log(`layer: ${layer.digest} (${layer.size} bytes)`);
console.log(`config: ${config.mediaType}`);
console.log(`manifest: ${manifest.digest}`);
console.log("files: 5");

const runtimeClass = {
  apiVersion: "node.k8s.io/v1",
  kind: "RuntimeClass",
  metadata: { name: "wasm-wasmtime" },
  handler: "wasmtime",
  scheduling: {
    nodeSelector: { "runtime.codewiki.dev/wasmtime": "true" },
  },
};

const pod = {
  metadata: { name: "receipt-worker" },
  spec: {
    runtimeClassName: "wasm-wasmtime",
    containers: [{ name: "worker", image: "registry.example/receipt:v1" }],
  },
};

const configuredHandlers = new Set(["runc", "wasmtime"]);
const eligibleNodes = [
  { name: "worker-a", labels: { "runtime.codewiki.dev/wasmtime": "true" } },
  { name: "worker-b", labels: {} },
].filter(node =>
  Object.entries(runtimeClass.scheduling.nodeSelector)
    .every(([key, value]) => node.labels[key] === value),
);

console.log(`class selected: ${pod.spec.runtimeClassName === runtimeClass.metadata.name}`);
console.log(`handler configured: ${configuredHandlers.has(runtimeClass.handler)}`);
console.log(`eligible nodes: ${eligibleNodes.map(node => node.name).join(", ")}`);