feat: add http-gateway library and cloudflare gateway example project

.gitignore

@@ -5,6 +5,7 @@ dist/
 pocket-ic
 .env
 Cargo.lock
+.wrangler
 
 .DS_Store
 .idea

README.md

@@ -20,10 +20,9 @@ You can read more about this protocol in [the spec](https://github.com/dfinity/i
 
 ## Related Projects
 
-- [Response Verification](https://github.com/dfinity/response-verification/)
-- [Service Worker](https://github.com/dfinity/ic/tree/master/typescript/service-worker)
-- [ICX Proxy](https://github.com/dfinity/ic/tree/master/rs/boundary_node/icx_proxy)
+- [ic-gateway](https://github.com/dfinity/ic-gateway)
 - [Desktop HTTP Proxy](https://github.com/dfinity/http-proxy)
+- [Response Verification](https://github.com/dfinity/response-verification)
 
 ## Contributing
 

examples/http-gateway/cloudflare/README.md

@@ -0,0 +1,19 @@
+# Cloudflare Worker based ICP HTTP Gateway
+
+## Environment variables
+
+Set the `API_GATEWAY` and `CANISTER_ID` variables in the `wrangler.json` file. Run `pnpm run -F http-gateway-cloudflare-example cf-typegen` to regenerate the `worker-configuration.d.ts` file.
+
+## Notes
+
+- Do not alter the response body, status codes or headers in any way. Local HTTP Gateways on an end user's computer may re-validate the response and reject it if it has been altered.
+
+## Possible optimizations
+
+- Early hints:
+  - https://developers.cloudflare.com/workers/examples/103-early-hints/.
+  - https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Link.
+  - Link headers should be set on the canister side and certified. The implementation of this will depend on the frontend framework and bundler that is used.
+- Cache control:
+  - Cloudflare reads the `Cache-Control` header and caches the response based on the value of the header.
+  - This header should be completely controlled by the canister.

examples/http-gateway/cloudflare/package.json

@@ -0,0 +1,16 @@
+{
+  "name": "http-gateway-cloudflare-example",
+  "version": "0.0.0",
+  "private": true,
+  "scripts": {
+    "start": "wrangler dev",
+    "deploy": "wrangler deploy",
+    "cf-typegen": "wrangler types"
+  },
+  "dependencies": {
+    "@dfinity/http-gateway": "workspace:*"
+  },
+  "devDependencies": {
+    "wrangler": "^4.14.3"
+  }
+}

examples/http-gateway/cloudflare/src/index.ts

@@ -0,0 +1,40 @@
+import { HttpGatewayClient } from '@dfinity/http-gateway';
+import { HttpAgent } from '@dfinity/agent';
+import RESPONSE_VERIFICATION_WASM from '@dfinity/response-verification/dist/web/web_bg.wasm';
+
+export default {
+  async fetch(request, env): Promise<Response> {
+    const cachedResponse = await caches.default.match(request);
+    if (cachedResponse) {
+      return mapResponse(cachedResponse);
+    }
+
+    const agent = HttpAgent.createSync({ host: env['API_GATEWAY'] });
+    const client = new HttpGatewayClient({
+      agent,
+      responseVerificationWasm: RESPONSE_VERIFICATION_WASM,
+      canisterId: env['CANISTER_ID'],
+    });
+
+    const response = await client.request({
+      request,
+    });
+
+    await caches.default.put(request, mapResponse(response.clone()));
+
+    return mapResponse(response);
+  },
+} satisfies ExportedHandler<Env>;
+
+function mapResponse(res: Response): Response {
+  return new Response(res.body, {
+    headers: res.headers,
+    status: res.status,
+    // This prevents Cloudflare from automatically encoding the response body
+    // according to the response's Content-Encoding header. Otherwise, the
+    // response body would be double-encoded.
+    //
+    // See: https://developers.cloudflare.com/workers/runtime-apis/response/#parameters
+    encodeBody: 'manual',
+  });
+}

examples/http-gateway/cloudflare/tsconfig.json

@@ -0,0 +1,17 @@
+{
+  "extends": "../../../tsconfig.json",
+	"compilerOptions": {
+		"target": "es2021",
+		"lib": ["es2021"],
+		"module": "es2022",
+		"moduleResolution": "Bundler",
+		"resolveJsonModule": true,
+		"allowJs": true,
+		"checkJs": false,
+		"noEmit": true,
+		"isolatedModules": true,
+		"allowSyntheticDefaultImports": true
+	},
+	"exclude": ["test"],
+	"include": ["worker-configuration.d.ts", "typings.d.ts", "src/**/*.ts"]
+}

examples/http-gateway/cloudflare/typings.d.ts

@@ -0,0 +1,4 @@
+declare module '@dfinity/response-verification/dist/web/web_bg.wasm' {
+  const value: Uint8Array;
+  export default value;
+}