Modern and Module Federation: assetPrefix vs getPublicPath

[42tg]

Hi,

I still try to setup an working Module Federation to use by my Company. After tackling a while with different Build tools (all based on rspack for the most part) I struggle hard to integrate an modern js remote into an modern js host application.

It still tries to load the remote sources from its own domain (eg mf-host-app.internal.domain) and after that I tried to put an getPublicPath configuration to the module-federation.config.ts but it seems that this gets somehow overwritten.

When I then configure output.assetPrefix as mentioned in the docs it also appears into something wich I would assume is the getPublicPath function from Module Federation. (when I'm closer look into the remoteEntry.js in the build output).

So far so fine but weirdly enough the modern deploy starts to respond on all routes with the generated index.html instead of serving assets, and I still struggling to find the root cause of that.

As I'm unsure now what should I use to deploy my Application correctly ? And it is maybe noteworthy to prefer assetPrefix over getPublicPath ?

I double checked the examples regarding that as well but could not find any clue why assetPrefix causes such a weird behaviour.

Greetings

[zllkjc]

The problem is that the current version of Modern.js server doesn't manage MF products well enough.

Previously, we recommended developers to upload all MF products to CDN (for example, manifest.json, remoteEntry.js, etc.) instead of directly using the Modern.js server. Therefore, when using the Modern.js server to handle these resources (for example, modern build + modern serve or run index.js after modern deploy), we will encounter some problems.

For example, you mentioned "404". I think it's because when you configure assetPrefix, static resources can't be matched, and if you don't configure this value, MF can't correctly obtain the resources of remote modules.

We have fixed all these issues in the latest MR like #7155.

I believe you can find the answer in this issue #7075. I've released the latest code to the canary version and verified it in the repository provided by joselrodrigues.

These changes will be released in Thursday's version, and then I will update the examples in Modern.js Example.

---

After this, the application of SSR or CSR, whether you run it with dev, serve, or deploy commands, you will get the same result.

In the production environment, you can deploy MF resources directly using the server of Modern.js without upload resources to CDN, and keep it consistent with the development phase. The only thing you need to do is configure output.assetPrefix.

[zllkjc]

Thank you for your support of Modern.js~ If you have any other questions, feel free to ask me in the above issue, or continue to ask me here.

[42tg]

Thanks alot for the quick Answer,

thats awesome that you already working on that.
As I'm resides in Europe our usage of CDN's is still quite medieval. But as far as I understand it would be sufficient to host the static Files somewhere (Docker + Nginx) and still deploy another Container wich runs the modern deploy output ?

(at least until your PR is merged)

But to be precise the recommended way to manipulate the Public Path for Modern JS + Module Federation is through output.assetPrefix?

[zllkjc]

Yeah..you can see the product mf-manifest.json:

There is a configuration for publicPath in this file, which comes from the output.assetPrefix of modern.js. This is also the reason why, when no configuration is set, resource files are always requested from the current domain name.

[zllkjc]

But I think this configuration should work with getPublicPath, and getPublicPath should have a higher priority. I will confirm this issue and reply to you later.

[42tg]

Yeah, in development it does but in production all strings I want to return are stripped away.

At least in my remoteEntry.js. Have to check the manifest also.

[zllkjc]

#7189