Question about cloud edge functions support

[elct9620]

Hi,

I find the microblog document has some notes about Recently, cloud edge functions like Cloudflare Workers have also gained popularity as JavaScript runtimes

Does Fedify expect to support it natively?

If I choose to use Cloudflare Workers, I need to use the Bindings feature to get the key-value store.

interface Bindings {
  Cache: KVNamespace;
}

const app = new Hono<{ Bindings: Bindings }>()

// ...
app.use(federation(fedi, (ctx) => {
   // the "ctx.env.Cache" is here
  return // ...
}));  

However, the Federation object is required kv and initialized before handling the request.

const fedi = createFederation<string>({
  // ctx.env.Cache is not available yet
});

const app = new Hono();
app.use(federation(fedi, (ctx) => "context data"));  

Or the expected usage is like this

interface Bindings {
  Cache: KVNamespace;
}

const app = new Hono<{ Bindings: Bindings }>()

app.use(async (ctx, next) => {
  const fedi = createFederation<string>({
    kv: new MyKVStore(ctx.env.Cache)
  });
  
  ctx.set('fedi', fedi) // use this later

  await next()
});  

[dahlia]

Creating a Federation instance for every request technically makes no problem, but I doubt that Fedify currently work well on Cloudflare Workers, as it's never tested on that. 🤔

[elct9620]

I will test it before I start my project. If I encounter any problems, I will report them or make a PR.

[elct9620]

Tested with Cloudflare Workers (local dev mode) but the shim-deno broke it.

✘ [ERROR] service core:user:poc-fedify: Uncaught ReferenceError: __dirname is not defined

    at null.<anonymous> (index.js:4178:186) in
  node_modules/@deno/shim-deno/dist/deno/stable/variables/mainModule.js
    at null.<anonymous> (index.js:32:50) in __require2
    at null.<anonymous> (index.js:6211:27) in
  node_modules/@deno/shim-deno/dist/deno/stable/variables.js
    at null.<anonymous> (index.js:32:50) in __require2
    at null.<anonymous> (index.js:11061:26) in
  node_modules/@deno/shim-deno/dist/deno/stable/functions.js
    at null.<anonymous> (index.js:32:50) in __require2
    at null.<anonymous> (index.js:11503:18) in node_modules/@deno/shim-deno/dist/deno/stable/main.js
    at null.<anonymous> (index.js:32:50) in __require2
    at null.<anonymous> (index.js:11541:18) in node_modules/@deno/shim-deno/dist/deno.js
    at null.<anonymous> (index.js:32:50) in __require2

It seems some packages or features are not supported by Cloudflare Worker.
https://developers.cloudflare.com/workers/runtime-apis/nodejs/

Is it possible to avoid using shim in Fedify for better capabilities?

[dahlia]

We're willing to support edge functions including Cloudflare Workers in a long term, but I guess it wouldn't be trivial in a short term… 😭 One cloud edge function I've tested with Fedify is Deno Deploy at the moment.

[dahlia]

Ah, Fedify on JSR would work better with edge functions.

[elct9620]

Switching to npx jsr add @fedify/fedify can resolve the shim issue. However, it throws a Temporal is not defined error.

I use new SimpleKvStore() here, but not relate it because I created a mock store that still does not work.

✘ [ERROR] ReferenceError: Temporal is not defined

      at kvCache
  (file:///Users/elct9620/Desktop/poc-fedify/node_modules/@fedify/fedify/runtime/docloader.ts:356:26)
      at new FederationImpl
  (file:///Users/elct9620/Desktop/poc-fedify/node_modules/@fedify/fedify/federation/middleware.ts:354:53)
      at createFederation
  (file:///Users/elct9620/Desktop/poc-fedify/node_modules/@fedify/fedify/federation/middleware.ts:245:10)
      at Array.<anonymous> (file:///Users/elct9620/Desktop/poc-fedify/src/index.ts:7:16)
      at Object.dispatch
  (file:///Users/elct9620/Desktop/poc-fedify/node_modules/hono/dist/hono-base.js:187:37)
      at Object.fetch
  (file:///Users/elct9620/Desktop/poc-fedify/node_modules/hono/dist/hono-base.js:213:17)
      at fetchDispatcher
  (file:///Users/elct9620/Desktop/poc-fedify/.wrangler/tmp/bundle-ZHjIs9/middleware-loader.entry.ts:54:17)
      at __facade_invokeChain__
  (file:///Users/elct9620/Desktop/poc-fedify/node_modules/wrangler/templates/middleware/common.ts:53:9)
      at Object.next
  (file:///Users/elct9620/Desktop/poc-fedify/node_modules/wrangler/templates/middleware/common.ts:50:11)
      at jsonError
  (file:///Users/elct9620/Desktop/poc-fedify/node_modules/wrangler/templates/middleware/middleware-miniflare3-json-error.ts:22:30)

[elct9620]

Updated:

Fixed, the typo caused the web finger not to return anything.

---

I can run it correctly after adding polyfill.

According to the tutorial - https://fedify.dev/tutorial/basics#actor-dispatcher

I can call curl -H "Accept: application/activity+json" http://localhost:8787/users/me to get the correct response, but Web Finger (curl "http://localhost:8787/.well-known/webfinger?resource=acct:me@localhost:887") returns 404.

[dahlia]

Could you try a polyfill for Temporal API?

[scruffymongrel]

I can call curl -H "Accept: application/activity+json" http://localhost:8787/users/me to get the correct response, but Web Finger (curl "http://localhost:8787/.well-known/webfinger?resource=acct:me@localhost:887") returns 404.

@elct9620, shouldn't resource=acct:me@localhost:887 be resource=acct:me@localhost:8787?

Also, did you manage to get Fedify working with Cloudflare Workers?

[valtlai]

I got Fedify working on Cloudflare Workers by

• using the JSR version (as suggested earlier in this thread)
• adding the Temporal polyfill (as suggested earlier in this thread)
• stripping import attributes from the .js files in the @fedify/fedify module.

For the last one, I used this dirty solution:

// package.json

{
  "scripts": {
+    "prepare": "node ./patch-fedify-for-workers.js"
  }
}

// patch-fedify-for-workers.js

import { glob, readFile, writeFile } from 'node:fs/promises';
import { join } from 'node:path';

const cwd = 'node_modules/@fedify/fedify';
const codeToDelete = ' with {\n  type: "json"\n}';

for await (const entry of glob('*/*.js', { cwd })) {
  (async () => {
    const filePath = join(cwd, entry);
    const originalContent = await readFile(filePath, 'utf8');
    const patchedContent = originalContent.replace(codeToDelete, '');
    if (originalContent !== patchedContent) {
      await writeFile(filePath, patchedContent);
    }
  })();
}

The prepare lifecycle script automatically runs after npm install.

This could be done better with esbuild, but I think this is good enough for myself as a temporary solution. I assume Workers will eventually support import attributes (and the Temporal API as well).